The DOI matches its Crossref record; 88 of the 91 references it cites were found in a registry or an index; 45 of the 224 sources its claims cite were checked for support.
School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: A Review of the Literature
Open accessAbstract
BACKGROUND: Insufficient sleep in adolescents has been shown to be associated with a wide variety of adverse outcomes, from poor mental and physical health to behavioral problems and lower academic grades. However, most high school students do not get sufficient sleep. Delaying school start times for adolescents has been proposed as a policy change to address insufficient sleep in this population and potentially to improve students' academic performance, reduce engagement in risk behaviors, and improve health. METHODS: This article reviews 38 reports examining the association between school start times, sleep, and other outcomes among adolescent students. RESULTS: Most studies reviewed provide evidence that delaying school start time increases weeknight sleep duration among adolescents, primarily by delaying rise times. Most of the studies saw a significant increase in sleep duration even with relatively small delays in start times of half an hour or so. Later start times also generally correspond to improved attendance, less tardiness, less falling asleep in class, better grades, and fewer motor vehicle crashes. CONCLUSIONS: Although additional research is necessary, research results that are already available should be disseminated to stakeholders to enable the development of evidence-based school policies.
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Claims the paper makes
45 of 224 cited sources checked · 34 supported · 0 flagged · accuracy not yet measured
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“Insufficient sleep has been linked to excess weight,6–13 decreased physical activity,14 and increased food intake, possibly due to alterations in appetite-regulating hormones.12”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > BACKGROUND
What the sources say
- Partly supportedcites [6] sourceExperimental — accuracy not yet measured
Section 3.5 reports that shorter sleep was associated with greater odds of obesity among female US high school students. It found no significant association among male students, so the source does not establish the link across adolescents generally; the Conclusion also describes a negative association in younger children while noting inconsistencies across age groups. No page numbers are provided in our copy. (LLM, conf=0.85)
- Not checked — no full text of the sourcecites [7] source
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- Not checked — no full text of the sourcecites [13] source
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes- Partly supported
The sources with a verdict support this claim; the rest weren’t checked yet, have no full text we could read, or their verdicts aren’t rated yet.
In the paper
“Results of investigations into longitudinal changes in weight attributable to sleep duration, however, have been mixed.10,15”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > BACKGROUND
What the sources say
- Not checked — no full text of the sourcecites [10] source
- Supportedcites [15] source
The Discussion states that longitudinal evidence on sleep and weight in adults has been mixed, describing studies with inverse, U-shaped, and no longitudinal associations. It also says the evidence for an association in adolescents and adults is mixed. (LLM, conf=0.91)
Strength:plain· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesThe sources with a verdict support this claim; the rest weren’t checked yet, have no full text we could read, or their verdicts aren’t rated yet.
In the paper
“A solid body of literature has found that insufficient sleep in this young population is tied to poor mental health, including depression, depressive symptoms,8,16–22 and suicidal ideation.8,18,20,22–25”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > BACKGROUND
What the sources say
- Not checked — no full text of the sourcecites [8] source
- Supportedcites [18] source
The Discussion states that shorter sleep duration and adolescents’ perceptions of not getting enough sleep are associated with suicidal ideation. This supports the citing sentence’s claim of a link, without requiring a causal interpretation. (LLM, conf=0.93)
- Not checked — no full text of the sourcecites [20] source
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- Supportedcites [23] source
The Introduction says shorter sleep was associated with greater suicidal ideation or attempts, especially among adolescents. “What This Study Adds” also describes an association between sleep duration and suicidal ideation or attempts among Korean adolescents. (LLM, conf=0.93)
- Not checked — no full text of the sourcecites [24] source
- Not checked — no full text of the sourcecites [25] source
Tests✓ Asserted: passes✓ Checkable: passes✓ Load-bearing: passes✓ Based: passesThe sources with a verdict support this claim; the rest weren’t checked yet, have no full text we could read, or their verdicts aren’t rated yet.
In the paper
“A solid body of literature has found that insufficient sleep in this young population is tied to poor mental health, including depression, depressive symptoms,8,16–22 and suicidal ideation.8,18,20,22–25”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > BACKGROUND
What the sources say
- Not checked — no full text of the sourcecites [8] source
- Not checked — no full text of the sourcecites [16] source
- Not checked — no full text of the sourcecites [17] source
- Supportedcites [18] source
The Abstract reports associations between inadequate sleep and depression and depressive symptoms in adolescents, as well as between short sleep and suicidal ideation. The Discussion also reports that adolescents with depression or suicidal ideation had shorter sleep durations and were more likely to perceive that they were not getting enough sleep. Page numbers are not provided in our copy. (LLM, conf=0.93)
- Not checked — no full text of the sourcecites [19] source
- Not checked — no full text of the sourcecites [20] source
- Not checked — no full text of the sourcecites [21] source
- Not checked — no full text of the sourcecites [22] source
Tests✓ Asserted: passes✓ Checkable: passes✓ Load-bearing: passes✓ Based: passesEvery source the paper cites for this claim was checked and supports it.
In the paper
“Short sleep duration has also been found to be associated with a higher risk of unintentional injury.30”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > BACKGROUND
What the sources say
- Supportedcites [30] source
The Results (p. 4) report that adolescents sleeping less than 7 hours per night had significantly higher odds of multiple unintentional injuries than those sleeping 7 hours or more. The association with a single injury was not statistically significant, but the finding for multiple injuries supports the cited statement. (LLM, conf=0.91)
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes- Supported
Every source the paper cites for this claim was checked and supports it.
In the paper
“In addition, a few studies have shown an association between insufficient sleep and unhealthy risk behaviors including alcohol use,17,19,20,22 tobacco smoking,20,22 marijuana use,20,22 use of other illicit/prescription drugs,22 unhealthy weight control strategies,26 and recent sexual activity.20”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > BACKGROUND
What the sources say
- Supportedcites [26] source
The Conclusion reports an association between self-reported short sleep duration and unhealthy weight-control behaviors. The Discussion likewise says very short sleep was associated with a higher prevalence of these behaviors among male and female high school students. (LLM, conf=0.94)
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes- Supported
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“Rise times, on the other hand, are primarily determined by a single factor—school start times.43”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > BACKGROUND
What the sources say
- Partly supportedcites [43] sourceExperimental — accuracy not yet measured
The Results and Discussion identify school start time as the strongest predictor of wake time among adolescents on school days. The claim omits that condition: the Results also report a strong weekend effect, so the paper does not establish school start time as the primary determinant of rise times generally. (LLM, conf=0.88)
Tests✓ Asserted: passes✓ Checkable: passes✓ Load-bearing: passes✓ Based: passes- Partly supported
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“Not surprisingly, students at schools with later start times got out of bed later on school days than those at earlier starting schools.35,36,50,53,55,56,60,62–69”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
What the sources say
- Not checked — no full text of the sourcecites [35] source
- Partly supportedcites [36] sourceExperimental — accuracy not yet measured
In Results (Part Three, Table 6), children at schools with later start times had later mean wake times than those at control schools after the intervention: 7:13 and 7:16 versus 7:01. But Methods (Measures) says mean wake time combined weekdays and weekends; the reported comparison does not establish the claim specifically for school days. Page numbers are unavailable in our copy. (LLM, conf=0.84)
- Not matchedcites [50]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
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Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- Not checked — no full text of the sourcecites [55] source
- Not matchedcites [56]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- Supportedcites [60]
The Executive Summary reports that high school students in District A, which adopted a later start time, got up roughly an hour later on school days than students in two comparable districts with earlier start times. This directly supports the attributed comparison. (LLM, conf=0.94)
- Not checked — no full text of the sourcecites [62] source
- Not checked — no full text of the sourcecites [63]
- Not checked — no full text of the sourcecites [64] source
Tests✓ Asserted: passes✓ Checkable: passes✓ Load-bearing: passes✓ Based: passes- Rests on an assumption: The 38 reviewed reports are sufficiently comparable in design, measures, and populations to be synthesized into general conclusions about school start times.
Every source the paper cites for this claim was checked and supports it.
In the paper
“In Paksarian et al, bedtimes were delayed by only 10 minutes for each 30 minute delay in school start times.71”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
What the sources say
- Supportedcites [71] source
The Results (Weeknight Bedtime) report that each half-hour later school start time was associated with a 10.48-minute later bedtime after adjustment. The claim accurately rounds that estimate to 10 minutes; the paper describes an association, not an observed effect of changing a school's start time. (LLM, conf=0.92)
Strength:plain· not yet calibratedCausal:direct· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes- Rests on an assumption: The 38 reviewed reports are sufficiently comparable in design, measures, and populations to be synthesized into general conclusions about school start times.
- Supported
The sources with a verdict support this claim; the rest weren’t checked yet, have no full text we could read, or their verdicts aren’t rated yet.
In the paper
“Of 19 studies that evaluated the association between school start times and bedtime, there were no start time-associated differences in weekday bedtimes in eleven studies.35,50,53–55,60,62,67,68,70”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
What the sources say
- Not checked — no full text of the sourcecites [35] source
- Not matchedcites [50]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- Not matchedcites [53]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- Not matchedcites [54]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- Not checked — no full text of the sourcecites [55] source
- Supportedcites [60]
Table 1 in the Report Introduction and Findings reports school-night bedtimes of 11:21, 11:20, and 11:09 p.m. for the three high schools and marks them with the same significance superscript, indicating no statistically significant difference. This report supports the finding for one study; it does not itself establish the citing sentence’s count of eleven out of nineteen studies. (LLM, conf=0.91)
- Not checked — no full text of the sourcecites [62] source
- Not checked — no full text of the sourcecites [67] source
- Not checked — no full text of the sourcecites [68] source
- Not checked — no full text of the sourcecites [70] source
Strength:plain· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes- Rests on an assumption: The 38 reviewed reports are sufficiently comparable in design, measures, and populations to be synthesized into general conclusions about school start times.
The sources with a verdict support this claim; the rest weren’t checked yet, have no full text we could read, or their verdicts aren’t rated yet.
In the paper
“However, six studies observed a later bedtime among students in schools that started at later times.34,36,56,64,66,71”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
What the sources say
- Not checked — no full text of the sourcecites [34] source
- Supportedcites [36] source
The Results (Part Three, Table 6; page not provided) show later bedtimes at follow-up in both school-start-delay groups: 21:20 to 21:34 and 21:25 to 21:37. This supports citing the study as one that observed later bedtimes among students whose schools started later; the table also shows a later bedtime in the control group. (LLM, conf=0.91)
- Not matchedcites [56]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- Not checked — no full text of the sourcecites [64] source
- Not checked — no full text of the sourcecites [66] source
- Supportedcites [71] source
The Results (Weeknight Bedtime) report that adolescents at schools with later start times went to bed later after adjustment. This paper supports its inclusion as one of the six cited studies; it does not need to establish the findings of the other five. (LLM, conf=0.93)
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes- Rests on an assumption: The 38 reviewed reports are sufficiently comparable in design, measures, and populations to be synthesized into general conclusions about school start times.
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“In 29 reports, a later start time was found to be associated with longer weekday sleep duration,34,36,38,51–56,60–79 including the studies that noted later bedtimes.34,36,56,64,66,71”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
What the sources say
- Not checked — no full text of the sourcecites [34] source
- Partly supportedcites [36] sourceExperimental — accuracy not yet measured
The Discussion (Main Findings and Significance) reports that a 30-minute delay in school start time increased sleep duration by 25.2 minutes, supporting this paper’s inclusion among reports of longer sleep after later starts. The Methods (Measures) say the reported mean combines weekday and weekend sleep; the cited paper does not report the intervention’s effect on weekday sleep duration separately. The count of 29 reports is not a finding this individual paper could establish. (LLM, conf=0.82)
- Supportedcites [38] source
In “School Start Times and the Sleep Habits or Problems,” the paper reports that earlier starts were associated with shorter weekday sleep. This supports citing it as one of the reports linking later start times with longer weekday sleep; the count of 29 reports describes the citing paper’s collection, not a finding attributed to this individual study. (LLM, conf=0.91)
- Not matchedcites [51]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- Not matchedcites [52]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- Not matchedcites [53]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- Not matchedcites [54]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- Not checked — no full text of the sourcecites [55] source
- Not matchedcites [56]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- Not matchedcites [60]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
Tests✓ Asserted: passes✓ Checkable: passes✓ Load-bearing: passes✓ Based: passes- Rests on an assumption: The 38 reviewed reports are sufficiently comparable in design, measures, and populations to be synthesized into general conclusions about school start times.
The sources with a verdict support this claim; the rest weren’t checked yet, have no full text we could read, or their verdicts aren’t rated yet.
In the paper
“Eleven of the positive studies found that students got at least one additional minute of sleep for every two minutes of difference in start time (eg, at least 30 minutes more sleep when start time was one hour later),34,55,56,60,61,64,65,68,70,72,78”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
What the sources say
- Not checked — no full text of the sourcecites [34] source
- Not checked — no full text of the sourcecites [55] source
- Not matchedcites [56]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- Supportedcites [60]
The report’s Executive Summary says District A students got a full hour more sleep per school night than students in two comparable districts with earlier start times. Table 4 lists starts at 8:30 a.m. in District A versus 7:25 and 7:15 a.m. in the other districts, so this study meets the cited threshold of at least one extra minute of sleep per two minutes of later start time. The report does not establish the aggregate count of eleven studies; it supports its own inclusion among them. (LLM, conf=0.90)
- Not matchedcites [61]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- Not checked — no full text of the sourcecites [64] source
- Not checked — no full text of the sourcecites [65] source
- Not checked — no full text of the sourcecites [68] source
- Not checked — no full text of the sourcecites [70] source
- Not checked — no full text of the sourcecites [72] source
Tests✓ Asserted: passes✓ Checkable: passes✓ Load-bearing: passes✓ Based: passes- Rests on an assumption: The 38 reviewed reports are sufficiently comparable in design, measures, and populations to be synthesized into general conclusions about school start times.
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“Another study observed a significantly longer sleep duration for 7th- and 8th-grade students of only one of two later-starting districts.60”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
What the sources say
- Partly supportedcites [60]Experimental — accuracy not yet measured
The Executive Summary says middle-school students in the two later-starting districts, B and C, got more sleep than those in District A. The Conclusions describe the same pattern, but the available passages do not establish that the difference was statistically significant in only one of those districts. (LLM, conf=0.78)
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes- Rests on an assumption: The 38 reviewed reports are sufficiently comparable in design, measures, and populations to be synthesized into general conclusions about school start times.
- Partly supported
The sources with a verdict support this claim; the rest weren’t checked yet, have no full text we could read, or their verdicts aren’t rated yet.
In the paper
“Two studies observed no difference in sleepiness based on school start times.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
What the sources say
- Not checked — no full text of the sourcecites [78] source
- Supportedcites [80]
The Discussion (page unavailable) reports no difference in daytime sleepiness between students whose schools started one hour earlier and those whose schools started later. This confirms the finding attributed to this study; the source alone does not establish what the other study found. (LLM, conf=0.91)
Strength:plain· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesThe sources with a verdict support this claim; the rest weren’t checked yet, have no full text we could read, or their verdicts aren’t rated yet.
In the paper
“students with later start times were less likely to report daytime sleepiness or falling asleep in class in nearly all studies that assessed these outcomes.34,36,55,56,60,64,65,69,72,74”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
What the sources say
- Not checked — no full text of the sourcecites [34] source
- Supportedcites [36] source
The Results (Part Three; page unavailable) report that daytime sleepiness decreased in both groups whose school start times were delayed, while it increased in the control group. This study supports the cited sentence’s daytime-sleepiness finding; the paper does not need to establish the pattern across all the other cited studies. (LLM, conf=0.90)
- Not checked — no full text of the sourcecites [55] source
Tests✓ Asserted: passes✓ Checkable: passes✓ Load-bearing: passes✓ Based: passesThe sources with a verdict support this claim; the rest weren’t checked yet, have no full text we could read, or their verdicts aren’t rated yet.
In the paper
“Three studies that included information about daytime naps noted that students with earlier school start times reported more napping,38,66,75”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
What the sources say
- Supportedcites [38] source
In “School Start Times and the Sleep Habits or Problems” (page not provided), the paper reports that students whose schools started before 7:30 were more likely to report naps after school. This supports the finding attributed to this study; the other two studies are not being attributed to this source alone. (LLM, conf=0.94)
- Not checked — no full text of the sourcecites [66] source
- Not matchedcites [75]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes- Supported
Every source the paper cites for this claim was checked and supports it.
In the paper
“Mean self-reported grades for the two districts that started before 7:30 AM were 6.4 and 6.5 (on a scale from 1 = mostly F’s to 9 = mostly A’s) compared to 7.1 for the district starting at 8:30 AM (p < .05).”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Academics and Cognition
What the sources say
- Supportedcites [60]
The self-reported-grades row in Table 4 (Discussion of Table 2: Student Academic Achievement; page unavailable) gives 7.08 for the 8:30 AM district and 6.50 and 6.37 for the 7:25 AM and 7:15 AM districts. These round to the cited values, and the table note says the differing superscripts indicate a difference at p < .05. (LLM, conf=0.93)
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes- Supported
The sources with a verdict support this claim; the rest weren’t checked yet, have no full text we could read, or their verdicts aren’t rated yet.
In the paper
“There was no consistent association between school start time and homework time.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Academics and Cognition
What the sources say
- Supportedcites [60]
Table 4 (Discussion of Table 2: Student Academic Achievement; page unavailable) shows no consistent pattern between start time and homework hours. District A started later and reported more homework than District B, but its homework hours were closer to those of District C, which started early like B. (LLM, conf=0.88)
- Not checked — no full text of the sourcecites [57] source
- Not checked — no full text of the sourcecites [67] source
Strength:plain· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes- Supported
Every source the paper cites for this claim was checked and supports it.
In the paper
“Among older students, U.S. Air Force Academy freshmen, students assigned to a first period course and therefore an earlier start to the school day had poorer grades.58”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Academics and Cognition
What the sources say
- Supportedcites [58] source
The Data section (p. 5) identifies the students as U.S. Air Force Academy freshmen and says they were randomly assigned to course periods. The Results (p. 14) report that students assigned a first-period course earned lower average grades in courses taken that day than students without one. (LLM, conf=0.94)
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes- Supported
Every source the paper cites for this claim was checked and supports it.
In the paper
“Hinrichs also evaluated the association between school start times and standardized test scores in Kansas (Kansas State Assessments) and the Virginia suburbs of Washington DC.59 Again, he found no association between school start times and academic achievement in these analyses.59”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Academics and Cognition
What the sources say
- Supportedcites [59] source
The Kansas State Assessment Analysis (p. 11) reports that school start times did not appear to affect reading scores and that the other assessed subjects also showed no effect. The Virginia End of Course Exam Analysis (p. 13) identifies its sample as roughly the Virginia suburbs of Washington, DC, and says its imprecise results gave no evidence of an effect on test scores. (LLM, conf=0.93)
Strength:plain· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes- Supported
Every source the paper cites for this claim was checked and supports it.
In the paper
“Hinrichs’ investigation into ACT scores and school start times in the Minneapolis-St. Paul area, which included school districts that did not delay school start times, controlled for various covariates and found no association between school start times and ACT scores.59”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Academics and Cognition
What the sources say
- Supportedcites [59] source
The Data and Empirical Methods section (p. 6) describes ACT data from 48 districts in the Twin Cities area and regressions controlling for covariates. The Results section (p. 8) reports that the adjusted estimates of the relationship between school start times and composite ACT scores were statistically insignificant. (LLM, conf=0.94)
Strength:plain· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes- Supported
Every source the paper cites for this claim was checked and supports it.
In the paper
“The first cross-sectional school start time study by the University of Minnesota found higher self-reported grades for students in later starting schools.60”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Academics and Cognition
What the sources say
- Supportedcites [60]
The Executive Summary reports that students in District A, which had a later high-school start time, reported higher grades than students in two similar earlier-starting districts. The Discussion of Table 2 repeats the finding while noting that other factors could explain the difference; the claim reports an association, not a causal effect. (LLM, conf=0.92)
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes- Supported
Every source the paper cites for this claim was checked and supports it.
In the paper
“In Milic et al.’s study in Croatia, students with an earlier school start time performed better academically than students at the schools with later start times.80”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Academics and Cognition
What the sources say
- Supportedcites [80]
The Abstract reports that students starting school earlier had better school success. The Discussion states that their school success was significantly better than that of students starting later, matching the claim about the Croatian study. (LLM, conf=0.94)
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes- Supported
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“Several studies included in this review found that earlier start times were also related to more frequent tardiness and more absences.55,57,60,61,64,65”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Attendance/Tardiness
What the sources say
- Not checked — no full text of the sourcecites [55] source
- Not checked — no full text of the sourcecites [57] source
- Partly supportedcites [60]Experimental — accuracy not yet measured
In Report Introduction and Findings (page unavailable), students at the later-start school reported significantly less lateness to class because of oversleeping than students at the two earlier-start schools. Table 1 in the same section shows slightly more days home sick at the earlier-start schools, but the difference was not statistically significant; it does not establish a relationship with absences generally. (LLM, conf=0.85)
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes- Rests on an assumption: Attendance matters for academic success.
The sources with a verdict support this claim; the rest weren’t checked yet, have no full text we could read, or their verdicts aren’t rated yet.
In the paper
“Students at later-starting schools appeared to experience fewer depression symptoms (lower depression scores).55,60,65,67”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Depression
What the sources say
- Not checked — no full text of the sourcecites [55] source
- Supportedcites [60]
The Executive Summary reports that students at the later-starting District A high school had fewer depressive feelings and behaviors than students at earlier-starting schools. The Abstract likewise describes fewer reports of depressive feelings and behaviors; the claim's cautious wording matches the report's observational framing. (LLM, conf=0.93)
- Not checked — no full text of the sourcecites [65] source
Tests✓ Asserted: passes✓ Checkable: passes✓ Load-bearing: passes✓ Based: passesEvery source the paper cites for this claim was checked and supports it.
In the paper
“However, one study of schools in the Minneapolis-St. Paul area found no association between school start times and overall attendance rates.59”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Attendance/Tardiness
What the sources say
- Supportedcites [59] source
Section III (p. 10) says the paper uses Minnesota school-level average daily attendance data to examine whether changes in attendance were attributable to later start times. The Conclusion (p. 17) says the analysis found no effect on school attendance, supporting the citing sentence’s description of no association. (LLM, conf=0.91)
Strength:plain· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes- Supported
Every source the paper cites for this claim was checked and supports it.
In the paper
“During the 2009–2010 school year, crash rates among 16–18 year olds were higher (p < .05) in the county with the earlier school start times.88”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Motor Vehicle Crashes
What the sources say
- Supportedcites [88] source
The Abstract reports that in 2009–2010, 16–18-year-old drivers in earlier-starting Chesterfield County had a higher crash rate than those in later-starting Henrico County: 48.8 versus 37.9 per 1,000 licensed drivers (p = 0.04). The Discussion likewise identifies the difference for 16–18-year-old drivers. (LLM, conf=0.94)
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes- Supported
Every source the paper cites for this claim was checked and supports it.
In the paper
“In 2007 and 2008, the teen crash rates were significantly higher in the city with an earlier school start time.87”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Motor Vehicle Crashes
What the sources say
- Supportedcites [87] source
The Conclusions (page not provided) state that teen crash rates were statistically significantly higher in Virginia Beach in both 2007 and 2008. The paper identifies Virginia Beach as the city with earlier high school start times. (LLM, conf=0.94)
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes- Supported
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“For both cities, teen crashes peaked during the morning commute time.87”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Motor Vehicle Crashes
What the sources say
- Partly supportedcites [87] sourceExperimental — accuracy not yet measured
The temporal-pattern passage reports a morning crash-rate peak in each city during the likely school commute. But the same section reports higher afternoon rates, including the greatest rate in Chesapeake, so the morning was not the overall peak in either city. (LLM, conf=0.88)
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes- Partly supported
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“Later start times also generally correspond to improved attendance, less tardiness, less falling asleep in class, better grades, and fewer motor vehicle crashes.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > Abstract > RESULTS
Tests✓ Asserted: passes✓ Checkable: passes✓ Load-bearing: passes✓ Based: passes- Rests on an assumption: The 38 reviewed reports are sufficiently comparable in design, measures, and populations to be synthesized into general conclusions about school start times.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“Most of the studies saw a significant increase in sleep duration even with relatively small delays in start times of half an hour or so.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > Abstract > RESULTS
Tests✓ Asserted: passes✓ Checkable: passes✓ Load-bearing: passes✓ Based: passes- Rests on an assumption: The 38 reviewed reports are sufficiently comparable in design, measures, and populations to be synthesized into general conclusions about school start times.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“Later start times also generally correspond to improved attendance, less tardiness, less falling asleep in class, better grades, and fewer motor vehicle crashes.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > Abstract > RESULTS
Tests✓ Asserted: passes✓ Checkable: passes✓ Load-bearing: passes✓ Based: passes- Rests on an assumption: The 38 reviewed reports are sufficiently comparable in design, measures, and populations to be synthesized into general conclusions about school start times.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“Later start times also generally correspond to improved attendance, less tardiness, less falling asleep in class, better grades, and fewer motor vehicle crashes.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > Abstract > RESULTS
Tests✓ Asserted: passes✓ Checkable: passes✓ Load-bearing: passes✓ Based: passes- Rests on an assumption: The 38 reviewed reports are sufficiently comparable in design, measures, and populations to be synthesized into general conclusions about school start times.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“Later start times also generally correspond to improved attendance, less tardiness, less falling asleep in class, better grades, and fewer motor vehicle crashes.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > Abstract > RESULTS
Tests✓ Asserted: passes✓ Checkable: passes✓ Load-bearing: passes✓ Based: passes- Rests on an assumption: The 38 reviewed reports are sufficiently comparable in design, measures, and populations to be synthesized into general conclusions about school start times.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“Later start times also generally correspond to improved attendance, less tardiness, less falling asleep in class, better grades, and fewer motor vehicle crashes.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > Abstract > RESULTS
Tests✓ Asserted: passes✓ Checkable: passes✓ Load-bearing: passes✓ Based: passes- Rests on an assumption: The 38 reviewed reports are sufficiently comparable in design, measures, and populations to be synthesized into general conclusions about school start times.
None of the sources cited for this claim have been checked yet.
In the paper
“In contrast to the majority of studies that observed longer sleep duration in later starting schools, two studies comparing students from schools with different start times did not observe a significant difference in sleep duration.35,50”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
What the sources say
- Not checked — no full text of the sourcecites [35] source
- Not matchedcites [50]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
Strength:plain· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes- Rests on an assumption: The 38 reviewed reports are sufficiently comparable in design, measures, and populations to be synthesized into general conclusions about school start times.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“The association between school start times and bedtimes, however, was mixed.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes- Rests on an assumption: The 38 reviewed reports are sufficiently comparable in design, measures, and populations to be synthesized into general conclusions about school start times.
A claim is checked only against the cited paper’s full text, never its abstract, and none is available for its sources.
In the paper
“Two studies unexpectedly reported earlier bedtimes after a delay in start times.65,69”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
What the sources say
Strength:plain· not yet calibratedCausal:direct· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes- Rests on an assumption: The 38 reviewed reports are sufficiently comparable in design, measures, and populations to be synthesized into general conclusions about school start times.
In the paper
“It should be noted that in the study by Wolfson and colleagues, this bedtime difference was observed only in the autumn.64”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
What the sources say
- Not checked — no full text of the sourcecites [64] source
Strength:plain· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes- Rests on an assumption: The 38 reviewed reports are sufficiently comparable in design, measures, and populations to be synthesized into general conclusions about school start times.
None of the sources cited for this claim have been checked yet.
In the paper
“although six other studies observed smaller, yet statistically significant, differences.51,52,62,63,73,74”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
What the sources say
- Not matchedcites [51]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- Not matchedcites [52]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- Not checked — no full text of the sourcecites [62] source
- Not checked — no full text of the sourcecites [63]
- Not checked — no full text of the sourcecites [73]
- Not checked — no full text of the sourcecites [74] source
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes- Rests on an assumption: The 38 reviewed reports are sufficiently comparable in design, measures, and populations to be synthesized into general conclusions about school start times.
- Not matched
In the paper
“Even with a delay in start time, falling asleep during class appears to remain a major problem, however.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
What the sources say
- Not matchedcites [61]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
Strength:hedged· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes- Not matched
A claim is checked only against the cited paper’s full text, never its abstract, and none is available for its sources.
In the paper
“Although nearly all the studies reviewed used self-reported sleep data either from sleep diaries or survey questions, the two studies that used data from electronic wrist monitors (actigraphs) worn during sleep confirmed the general finding of longer weeknight sleep duration for students with later start times.62,70”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
What the sources say
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes- Rests on an assumption: The 38 reviewed reports are sufficiently comparable in design, measures, and populations to be synthesized into general conclusions about school start times.
In the paper
“the mean inductive reasoning score, a measure of intelligence which is positively associated with attention, was significantly lower for the latest-starting school than the other two schools.77”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Academics and Cognition
What the sources say
- Not checked — no full text of the sourcecites [77] source
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIn the paper
“A longitudinal study of nearly 200 boarding school students did not see a change in self-reported grades after a 25 minute delay in school start times.67”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Academics and Cognition
What the sources say
- Not checked — no full text of the sourcecites [67] source
Strength:plain· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIn the paper
“In their latest longitudinal study including 8 schools, the same group noted that most schools saw an increase in grade point average after delaying school start times.61”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Academics and Cognition
What the sources say
- Not matchedcites [61]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
Strength:plain· not yet calibratedCausal:direct· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes- Not matched
A claim is checked only against the cited paper’s full text, never its abstract, and none is available for its sources.
In the paper
“Two studies found that students with later start times reported fewer problems concentrating and paying attention.70,72”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Academics and Cognition
What the sources say
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIn the paper
“One study asked students about caffeine consumption and observed that caffeine use decreased after a 25 minute delay in school start time.67”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
What the sources say
- Not checked — no full text of the sourcecites [67] source
Strength:plain· not yet calibratedCausal:direct· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes- Rests on an assumption: Adolescents who are sleepy might use caffeine to counteract their sleepiness.
In the paper
“a study in Spain measured attention level via a sustained attention task among students at three schools with different start times (8:00, 8:15, and 8:30) and observed the highest average attention level at the school starting at 8:15.77”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Academics and Cognition
What the sources say
- Not checked — no full text of the sourcecites [77] source
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIn the paper
“In the cross-sectional component of that study, an hour later start time corresponded to higher test scores on both math and reading (on the order of 3 percentile points).57”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Academics and Cognition
What the sources say
- Not checked — no full text of the sourcecites [57] source
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIn the paper
“However, the increase in grades observed from this group’s subsequent longitudinal study was small and not statistically significant.55”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Academics and Cognition
What the sources say
- Not checked — no full text of the sourcecites [55] source
Strength:plain· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIn the paper
“In the cross-sectional component of his study, Edwards found that students at schools that started later reported less time watching television.57”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Other Outcomes
What the sources say
- Not checked — no full text of the sourcecites [57] source
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIn the paper
“During the same time period, crash rates for this age group increased by 7.8% in the rest of the state.74”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Motor Vehicle Crashes
What the sources say
- Not checked — no full text of the sourcecites [74] source
Load-bearingStrength:plain· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes✓ Load-bearing: passes✓ Based: passesIn the paper
“In a Kentucky county, Danner and Phillips saw a 16.5% decrease (p < .01) in motor vehicle crash rates for 17- and 18-year-old students in the 2 years following a 1-hour delay in school start time by county high schools.74”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Motor Vehicle Crashes
What the sources say
- Not checked — no full text of the sourcecites [74] source
Tests✓ Asserted: passes✓ Checkable: passes✓ Load-bearing: passes✓ Based: passesIn the paper
“However, as recently reported by Owens et al.90 in their examination of school districts that have delayed school start times, many anticipated problems fail to materialize or are only temporary.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > IMPLICATIONS FOR SCHOOL HEALTH
What the sources say
- Not checked — no full text of the sourcecites [90] source
Strength:plain· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIn the paper
“However, within each grade, these behaviors were associated with shorter sleep duration”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Other Outcomes
What the sources say
- Not matchedcites [54]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes- Not matched
In the paper
“When he limited his analyses to schools that changed start times over the time course of the study, he confirmed that students at schools that delayed their start times reported significantly less time watching television.57”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Other Outcomes
What the sources say
- Not checked — no full text of the sourcecites [57] source
Strength:plain· not yet calibratedCausal:direct· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIn the paper
“However, when comparing 10th graders before and after the delay in high school start times, attendance rates were lower after the delay.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Attendance/Tardiness
What the sources say
- Not matchedcites [81]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
Strength:plain· not yet calibratedCausal:direct· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes- Not matched
In the paper
“In one study, even with delaying start times from 8:00 AM to 8:55 AM, nearly a third of students reported being late to class because of oversleeping in the 2 weeks before the survey.61”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Attendance/Tardiness
What the sources say
- Not matchedcites [61]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
Strength:plain· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes- Not matched
In the paper
“Among 197 boarding school students, no change in time spent in athletics or extracurricular activities was reported after a 25 minute delay in start time.67”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Other Outcomes
What the sources say
- Not checked — no full text of the sourcecites [67] source
Strength:plain· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIn the paper
“One study found no difference in students’ positive or negative affect with delayed school start time.78”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Depression
What the sources say
- Not checked — no full text of the sourcecites [78] source
Strength:plain· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesThe paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“Most of the studies saw a significant increase in sleep duration even with relatively small delays in start times of half an hour or so.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > CONCLUSION
Tests✓ Asserted: passes✓ Checkable: passes✓ Load-bearing: passes✓ Based: passesIn the paper
“Finally, in a small study of 15 students who transitioned from grade 9 (school start time 8:25) to grade 10 (school start time 7:20), self-reported conduct problems and aggressive behaviors decreased with the change to an earlier start time.54”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Other Outcomes
What the sources say
- Not matchedcites [54]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
Strength:plain· not yet calibratedCausal:direct· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes- Not matched
In the paper
“Several school districts have seen savings in transportation costs after changes made to facilitate delayed start times.90”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > IMPLICATIONS FOR SCHOOL HEALTH
What the sources say
- Not checked — no full text of the sourcecites [90] source
Strength:plain· not yet calibratedCausal:direct· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIn the paper
“Insufficient sleep has been linked to excess weight,6–13 decreased physical activity,14 and increased food intake, possibly due to alterations in appetite-regulating hormones.12”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > BACKGROUND
What the sources say
- Not checked — no full text of the sourcecites [12] source
Strength:hedged· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesA claim is checked only against the cited paper’s full text, never its abstract, and none is available for its sources.
In the paper
“In addition, a few studies have shown an association between insufficient sleep and unhealthy risk behaviors including alcohol use,17,19,20,22 tobacco smoking,20,22 marijuana use,20,22 use of other illicit/prescription drugs,22 unhealthy weight control strategies,26 and recent sexual activity.20”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > BACKGROUND
What the sources say
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesThe paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“Insufficient sleep in adolescents has been shown to be associated with a wide variety of adverse outcomes, from poor mental and physical health to behavioral problems and lower academic grades.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > Abstract > BACKGROUND
Tests✓ Asserted: passes✓ Checkable: passes✓ Load-bearing: passes✓ Based: passesIn the paper
“Insufficient sleep has been linked to excess weight,6–13 decreased physical activity,14 and increased food intake, possibly due to alterations in appetite-regulating hormones.12”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > BACKGROUND
What the sources say
- Not checked — no full text of the sourcecites [14] source
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIn the paper
“However, most high school students do not get sufficient sleep.”
- Also stated in: § BACKGROUND · plain
“fewer than 8% of high school students report getting this amount.4”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > Abstract > BACKGROUND
What the sources say
- Not checked — no full text of the sourcecites [4] source
Load-bearingStrength:plain· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes✓ Load-bearing: passes✓ Based: passes- Also stated in: § BACKGROUND · plain
A claim is checked only against the cited paper’s full text, never its abstract, and none is available for its sources.
In the paper
“Most adolescents may need at least 9 hours sleep per night1–3; however, fewer than 8% of high school students report getting this amount.4”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > BACKGROUND
What the sources say
Load-bearingStrength:hedged· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes✓ Load-bearing: passes✓ Based: passesIn the paper
“Less than a third of students report 8 or more hours of sleep, and this proportion decreases as school grade level increases so that fewer than a quarter of high school seniors get this amount.4”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > BACKGROUND
What the sources say
- Not checked — no full text of the sourcecites [4] source
Strength:plain· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesThe paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“Insufficient sleep in adolescents has been shown to be associated with a wide variety of adverse outcomes, from poor mental and physical health to behavioral problems and lower academic grades.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > Abstract > BACKGROUND
Tests✓ Asserted: passes✓ Checkable: passes✓ Load-bearing: passes✓ Based: passesIn the paper
“fewer than 8% of high school students report getting this amount.4”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > BACKGROUND
What the sources say
- Not checked — no full text of the sourcecites [4] source
Strength:plain· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesThe paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“Insufficient sleep in adolescents has been shown to be associated with a wide variety of adverse outcomes, from poor mental and physical health to behavioral problems and lower academic grades.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > Abstract > BACKGROUND
Tests✓ Asserted: passes✓ Checkable: passes✓ Load-bearing: passes✓ Based: passesA claim is checked only against the cited paper’s full text, never its abstract, and none is available for its sources.
In the paper
“In addition, a few studies have shown an association between insufficient sleep and unhealthy risk behaviors including alcohol use,17,19,20,22 tobacco smoking,20,22 marijuana use,20,22 use of other illicit/prescription drugs,22 unhealthy weight control strategies,26 and recent sexual activity.20”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > BACKGROUND
What the sources say
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIn the paper
“One of these negative studies failed to find a correlation between school night sleep duration and grade point average.37”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > BACKGROUND
What the sources say
- Not checked — no full text of the sourcecites [37] source
Strength:plain· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIn the paper
“Other factors that have been found to be associated with insufficient sleep include risk-taking behaviors,27 bullying,28 school violence-related behaviors,29 and physical fighting.20”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > BACKGROUND
What the sources say
- Not checked — no full text of the sourcecites [27] source
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIn the paper
“Other factors that have been found to be associated with insufficient sleep include risk-taking behaviors,27 bullying,28 school violence-related behaviors,29 and physical fighting.20”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > BACKGROUND
What the sources say
- Not checked — no full text of the sourcecites [20] source
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesA conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Adolescents tend to get insufficient sleep because of a combination of late bedtimes and early rise times.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > BACKGROUND
Tests✓ Asserted: passes✓ Checkable: passes✓ Load-bearing: passes✓ Based: passesWhat the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“The primary limitation to this review is its reliance on indexing by PubMed and Scopus, which could lead to omission of reports not indexed by these databases.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Methods
Strength:hedged· not yet calibratedCausal:conditional· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIn the paper
“In addition, a few studies have shown an association between insufficient sleep and unhealthy risk behaviors including alcohol use,17,19,20,22 tobacco smoking,20,22 marijuana use,20,22 use of other illicit/prescription drugs,22 unhealthy weight control strategies,26 and recent sexual activity.20”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > BACKGROUND
What the sources say
- Not checked — no full text of the sourcecites [20] source
Strength:hedged· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIn the paper
“Their natural body clocks can keep adolescents awake until 11 PM or later, in spite of going to bed earlier and good sleep hygiene, such as avoiding stimulating activity at night and minimizing caffeine intake in the afternoon or evening.39”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > BACKGROUND
What the sources say
- Not checked — no full text of the sourcecites [39] source
Tests✓ Asserted: passes✓ Checkable: passes✓ Load-bearing: passes✓ Based: passesIn the paper
“Other factors that have been found to be associated with insufficient sleep include risk-taking behaviors,27 bullying,28 school violence-related behaviors,29 and physical fighting.20”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > BACKGROUND
What the sources say
- Not checked — no full text of the sourcecites [29] source
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesA claim is checked only against the cited paper’s full text, never its abstract, and none is available for its sources.
In the paper
“In addition, a few studies have shown an association between insufficient sleep and unhealthy risk behaviors including alcohol use,17,19,20,22 tobacco smoking,20,22 marijuana use,20,22 use of other illicit/prescription drugs,22 unhealthy weight control strategies,26 and recent sexual activity.20”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > BACKGROUND
What the sources say
Strength:hedged· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIn the paper
“In addition, a few studies have shown an association between insufficient sleep and unhealthy risk behaviors including alcohol use,17,19,20,22 tobacco smoking,20,22 marijuana use,20,22 use of other illicit/prescription drugs,22 unhealthy weight control strategies,26 and recent sexual activity.20”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > BACKGROUND
What the sources say
- Not checked — no full text of the sourcecites [22] source
Strength:hedged· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIn the paper
“Other factors that have been found to be associated with insufficient sleep include risk-taking behaviors,27 bullying,28 school violence-related behaviors,29 and physical fighting.20”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > BACKGROUND
What the sources say
- Not checked — no full text of the sourcecites [28] source
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIn the paper
“A recent report found that short sleep duration was strongly associated with odds of school absences.82”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Attendance/Tardiness
What the sources say
- Not checked — no full text of the sourcecites [82] source
Strength:boosted· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesA conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“which indicates that at least some of the decrease in these behaviors may be due to maturation.54”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Other Outcomes
Strength:hedged· not yet calibratedCausal:conditional· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIn the paper
“Sleep is strongly linked with many psychiatric disorders, including depression and anxiety.83”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Depression
What the sources say
- Not checked — no full text of the sourcecites [83] source
Strength:boosted· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passes
- It may state two separate claims as one. 39
- Probably not a substantial claim. 20
The sources with a verdict support this claim; the rest weren’t checked yet, have no full text we could read, or their verdicts aren’t rated yet.
In the paper
“Finally, students who do not get enough sleep also may be more likely to have problems paying attention and poor academic performance,17,21,31–36 although not all research agrees.37,38”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > BACKGROUND
What the sources say
- Not checked — no full text of the sourcecites [17] source
- Not checked — no full text of the sourcecites [21] source
- Supportedcites [31] source
The Discussion reports a pathway in teenagers from short sleep duration through daytime somnolence and reduced attention to lower academic achievement. The Conclusions likewise report correlations among these variables. The citing sentence uses tentative language; its caveat that not all research agrees is attached to other citations, not this source. (LLM, conf=0.92)
- Not checked — no full text of the sourcecites [32] source
- Not checked — no full text of the sourcecites [33] source
- Not checked — no full text of the sourcecites [34] source
- Not checked — no full text of the sourcecites [35] source
- Supportedcites [36] source
The Introduction links insufficient sleep to attention problems, and the Results report that children sleeping under nine hours had higher odds of poor academic achievement. The Discussion says daytime sleepiness and, in some cases, short sleep duration were associated with impaired attention and achievement. The citing sentence assigns the qualification about research disagreement to other citations. (LLM, conf=0.92)
- Not checked — no full text of the sourcecites [37] source
- Supportedcites [38] source
The Discussion links sleep deprivation with reduced alertness and reports poorer school performance among students who did not make up weekday sleep loss. The paper qualifies the performance finding: short weekday sleep alone was not associated with poorer performance, whereas chronic sleep deprivation was. The claim’s ‘may’ is consistent with that qualification; its ‘not all research agrees’ caveat is attached to other citations. (LLM, conf=0.88)
Strength:hedged· not yet calibratedCausal:conditional· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIt may state two separate claims as one.
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“External factors that contribute to later bedtimes among adolescents include an increase in schoolwork; participation in afterschool activities, including employment; fewer parent-set bedtimes; and late-night use of technology in the bedroom.39–43”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > BACKGROUND
What the sources say
- Not checked — no full text of the sourcecites [39] source
- Not checked — no full text of the sourcecites [40] source
- Not checked — no full text of the sourcecites [41] source
- Partly supportedcites [42] sourceExperimental — accuracy not yet measured
The Introduction links later adolescent bedtimes to increased academic workload, part-time employment, and technology use, particularly in the bedroom. The Results and Discussion associate parent-set bedtimes with earlier bedtimes. The paper does not establish that afterschool activities generally, beyond employment, contribute to later bedtimes; its comparison of extracurricular commitments was between bedtime-setting groups, not a test of that claim. (LLM, conf=0.84)
- Partly supportedcites [43] sourceExperimental — accuracy not yet measured
The Results section (page not provided) associates more time spent working, using computers, and socializing with later bedtimes among US adolescents aged 15–17. It reports minimal effects for hours in school and does not establish increased schoolwork, fewer parent-set bedtimes, or technology use specifically in the bedroom. The Discussion also cautions that the activity associations do not establish causation. (LLM, conf=0.88)
Strength:plain· not yet calibratedCausal:direct· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIt may state two separate claims as one.
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“In further analysis, the authors found the longer sleep duration for boys only (20 minutes for each 30 minute delay in school start times) and that there was variation by urbanicity, with an increase in sleep duration for boys in major metropolitan”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
What the sources say
- Partly supportedcites [71] sourceExperimental — accuracy not yet measured
The Results (Interaction by Sex) report about 20 additional minutes of sleep for boys, but only for each 30-minute delay in start times before 8:01 am; no association was found from 8:01 am onward or for girls. The Results (Interaction by Urbanicity) also report variation by urbanicity, including increased sleep duration for boys in major metropolitan counties. The citing sentence omits the before-8:01-am limit on its 20-minute figure. (LLM, conf=0.88)
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIt may state two separate claims as one.
- Rests on an assumption: The 38 reviewed reports are sufficiently comparable in design, measures, and populations to be synthesized into general conclusions about school start times.
- Partly supported
Every source the paper cites for this claim was checked and supports it.
In the paper
“Paksarian et al. observed longer sleep durations with later school start times (11 minutes for each 30 minute delay in school start times), but only for schools that started before 8:01 AM.71”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
What the sources say
- Supportedcites [71] source
The Discussion reports an estimate of about 11 additional minutes of sleep per 30-minute later start before 8:01 am. It also describes a plateau beyond 8:01 am, matching the claim's qualification. (LLM, conf=0.94)
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIt may state two separate claims as one.
- Rests on an assumption: The 38 reviewed reports are sufficiently comparable in design, measures, and populations to be synthesized into general conclusions about school start times.
- Supported
The sources with a verdict support this claim; the rest weren’t checked yet, have no full text we could read, or their verdicts aren’t rated yet.
In the paper
“some evidence suggests a positive association between later school start time and academic performance,57,58,60,61,64,81 although the association may be relatively weak55 and not universal.59,67,80”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Academics and Cognition
What the sources say
- Not checked — no full text of the sourcecites [57] source
- Supportedcites [58] source
The paper supports the positive-link portion of the sentence: on p. 2, the authors report that later school starts significantly improve academic achievement. The sentence assigns the 'relatively weak' and 'not universal' qualifications to other citations, not necessarily to this paper. (LLM, conf=0.92)
- Not matchedcites [60]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
Tests✓ Asserted: passes✓ Checkable: passes✓ Load-bearing: passes✓ Based: passesIt may state two separate claims as one.
- Rests on an assumption: Grades are not standardized and differ across subjects, teachers, and schools.
- Rests on an assumption: Not all students take standardized tests like the SAT or ACT, and those who do are more likely to be college-bound.
- Rests on an assumption: Students who already perform very well before a start time delay have little room to improve.
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“The annual ACT participation rate among Minnesota high school graduates varied from 59% to 66% during the study period (1993–2002).59”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Academics and Cognition
What the sources say
- Partly supportedcites [59] sourceExperimental — accuracy not yet measured
In A. Data and Empirical Methods (p. 6), the paper reports annual ACT participation among Minnesota high school graduates ranging from 59% to 66%. It gives the participation-rate period as 1994–2002, not 1993–2002; the ACT test-score data begin in the 1993–94 school year. (LLM, conf=0.88)
Strength:plain· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes✗ Load-bearing: fails✓ Based: passesProbably not a substantial claim. The paper’s conclusions may not depend on it.
- Partly supported
Every source the paper cites for this claim was checked and supports it.
In the paper
“More time working has been linked to poorer academic performance.89”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Other Outcomes
What the sources say
- Supportedcites [89] source
The Results report that adolescents had lower GPAs when working intensive hours than when not working. The claim describes an association, not a causal effect, and is consistent with that finding. (LLM, conf=0.94)
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes✗ Load-bearing: fails✓ Based: passesProbably not a substantial claim. The paper’s conclusions may not depend on it.
- Supported
Every source the paper cites for this claim was checked and supports it.
In the paper
“The following year, crash rates among 16–17 year olds were higher (p < .05) in the same county, but difference was not statistically significant when 18 year olds were included in comparison (p = 0.09).88”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Motor Vehicle Crashes
What the sources say
- Supportedcites [88] source
Table 1 (page not provided) reports that in 2010–2011 Chesterfield County had a higher crash rate than Henrico County among 16–17-year-olds (p = 0.046). The difference for 16–18-year-olds was not statistically significant (p = 0.088), rounded to 0.09 in the Results. (LLM, conf=0.94)
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIt may state two separate claims as one.
- Supported
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“Most studies reviewed provide evidence that delaying school start time increases weeknight sleep duration among adolescents, primarily by delaying rise times.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > Abstract > RESULTS
Load-bearingCausal:direct· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes✓ Load-bearing: passes✗ Based: failsProbably not a substantial claim. The paper may give no reason why it holds. It may state two separate claims as one.
- Rests on an assumption: The 38 reviewed reports are sufficiently comparable in design, measures, and populations to be synthesized into general conclusions about school start times.
In the paper
“For one of these, the difference in sleep duration did not meet the authors’ effect size criterion, although the difference would not have been expected to be large since the difference in school start times was only 20 minutes.35”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
What the sources say
- Not checked — no full text of the sourcecites [35] source
Strength:plain· not yet calibratedSingle caseTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIt may state two separate claims as one.
- Rests on an assumption: The 38 reviewed reports are sufficiently comparable in design, measures, and populations to be synthesized into general conclusions about school start times.
In the paper
“In the study by Owens et al., some students stated that after seeing the benefits of getting more sleep with the delay in school start times, they sought to further increase their sleep by going to bed earlier.65”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
What the sources say
- Not checked — no full text of the sourcecites [65] source
Strength:plain· not yet calibratedCausal:direct· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes✗ Load-bearing: fails✓ Based: passesProbably not a substantial claim. The paper’s conclusions may not depend on it.
- Rests on an assumption: The 38 reviewed reports are sufficiently comparable in design, measures, and populations to be synthesized into general conclusions about school start times.
None of the sources cited for this claim have been checked yet.
In the paper
“Seven reports that evaluated weekend sleep patterns found more “catch-up” sleep on the weekends for earlier start times,51,61,64,66,69,74,78 although one found no difference in this outcome.71”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
What the sources say
- Not matchedcites [51]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- Not matchedcites [61]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- Not checked — no full text of the sourcecites [64] source
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIt may state two separate claims as one.
- Rests on an assumption: A gap between school-night and weekend sleep can signal that students are not getting enough sleep on school nights and are compensating on weekends.
- Not matched
In the paper
“The other study observed longer sleep duration for students at the later starting school, but the difference was not statistically significant.50”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
What the sources say
- Not matchedcites [50]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
Strength:plain· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIt may state two separate claims as one.
- Rests on an assumption: The 38 reviewed reports are sufficiently comparable in design, measures, and populations to be synthesized into general conclusions about school start times.
- Not matched
In the paper
“In Wahlstrom and colleagues’ survey of students post-start time change, 27% reported falling asleep in a morning class in the previous 2 weeks, and 29% fell asleep in an afternoon class.61”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
What the sources say
- Not matchedcites [61]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
Strength:plain· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIt may state two separate claims as one.
- Not matched
In the paper
“After an advance in start time from 8:25 AM to 7:20 AM, students had a shorter REM sleep latency (time between sleep onset and onset of REM sleep) on polysomnography and a shorter sleep latency (time to sleep onset during a standard testing protocol).62”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
What the sources say
- Not checked — no full text of the sourcecites [62] source
Strength:plain· not yet calibratedCausal:direct· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIt may state two separate claims as one.
In the paper
“Sleep duration for the second later-starting district was also longer than for the early-starting district, but the difference was not statistically significant.60”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
What the sources say
- Not matchedcites [60]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
Strength:plain· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIt may state two separate claims as one.
- Rests on an assumption: The 38 reviewed reports are sufficiently comparable in design, measures, and populations to be synthesized into general conclusions about school start times.
- Not matched
None of the sources cited for this claim have been checked yet.
In the paper
“Wahlstrom and colleagues found that students with later school start times reported less hours of homework,60 whereas Edwards observed the reverse57 and Boergers and colleagues saw no difference.67”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Academics and Cognition
What the sources say
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIt may state two separate claims as one.
In the paper
“One study assessed weeknight and weekend sleep and observed longer weeknight sleep duration and no change in weekend sleep patterns after a delay in school start time”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
What the sources say
- Not checked — no full text of the sourcecites [67] source
Strength:plain· not yet calibratedCausal:direct· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIt may state two separate claims as one.
In the paper
“The longitudinal component of the same report looked at schools that had changed school start times over the course of the study and found that a one hour delay in start time corresponded to a 2 percentile increase in math and 1.5 percentile increase in reading.57”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Academics and Cognition
What the sources say
- Not checked — no full text of the sourcecites [57] source
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIt may state two separate claims as one.
In the paper
“Wolfson and colleagues observed higher grades after delaying school start times for 8th grade, although not for 7th-grade students.64”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Academics and Cognition
What the sources say
- Not checked — no full text of the sourcecites [64] source
Strength:plain· not yet calibratedCausal:direct· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIt may state two separate claims as one.
In the paper
“The Norwegian study that delayed start times on Mondays included reaction time tests and found that students at the school with delayed start time had significantly fewer lapses and faster reaction times on Monday than Friday compared to no difference among students at the control (no delay) school.78”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Academics and Cognition
What the sources say
- Not checked — no full text of the sourcecites [78] source
Strength:plain· not yet calibratedCausal:direct· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIt may state two separate claims as one.
In the paper
“Arlington Public Schools (Arlington County, Virginia) observed an improvement in 10th grade students’ 1st period grades after a 45 minute delay in high school start times, with no change in 7th grade students’ 1st period grades after a 20 minute advance in middle school start times.81”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Academics and Cognition
What the sources say
- Not matchedcites [81]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
Strength:plain· not yet calibratedCausal:direct· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIt may state two separate claims as one.
- Not matched
In the paper
“One study saw that students at schools with later start times spent less time at work during the school week (p < .05).60”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Other Outcomes
What the sources say
- Not matchedcites [60]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes✗ Load-bearing: fails✓ Based: passesProbably not a substantial claim. The paper’s conclusions may not depend on it.
- Not matched
In the paper
“Despite this finding, academic performance improved for those students.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Attendance/Tardiness
What the sources say
- Not matchedcites [81]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIt may state two separate claims as one.
- Not matched
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“Although not all studies found that later start times corresponded to improved academic performance, no studies found a negative impact of later school start times on academics.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > CONCLUSION
Load-bearingStrength:plain· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes✓ Load-bearing: passes✓ Based: passesIt may state two separate claims as one.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“Later school start times also generally corresponded to improved attendance, less tardiness, less falling asleep in class, fewer depression symptoms, and fewer motor vehicle crashes.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > CONCLUSION
Tests✓ Asserted: passes✓ Checkable: passes✓ Load-bearing: passes✓ Based: passesIt may state two separate claims as one.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“Nearly all studies to date provide evidence that delaying school start time accomplishes the goal of increasing sleep duration among these students, primarily by delaying rise times.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > CONCLUSION
Tests✓ Asserted: passes✓ Checkable: passes✓ Load-bearing: passes✓ Based: passesIt may state two separate claims as one.
- Rests on an assumption: Adolescents as a group are largely sleep-deprived.
In the paper
“Two areas saw major decreases (≥65%) in teen crash rates after the delays, while one saw a small decrease (6%), and another saw a small increase (9%).61”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Motor Vehicle Crashes
What the sources say
- Not matchedcites [61]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
Strength:plain· not yet calibratedCausal:direct· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIt may state two separate claims as one.
- Not matched
In the paper
“Less than a third of students report 8 or more hours of sleep, and this proportion decreases as school grade level increases so that fewer than a quarter of high school seniors get this amount.4”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > BACKGROUND
What the sources say
- Not checked — no full text of the sourcecites [4] source
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIt may state two separate claims as one.
In the paper
“One of the early changes associated with puberty is alteration of a child’s circadian rhythms, such that adolescents are more alert in the afternoons and evenings and require morning sleep.44”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > BACKGROUND
What the sources say
- Not checked — no full text of the sourcecites [44] source
Tests✓ Asserted: passes✓ Checkable: passes✓ Load-bearing: passes✓ Based: passesIt may state two separate claims as one.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“That study also relied on a non-standardized measure of academic performance and did not adjust for variables such as grade in school, which is strongly related to prevalence of insufficient sleep.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > BACKGROUND
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIt may state two separate claims as one.
A claim is checked only against the cited paper’s full text, never its abstract, and none is available for its sources.
In the paper
“However, these programs may improve knowledge of sleep without having a significant effect on behavior.45,46”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > BACKGROUND
What the sources say
Strength:hedged· not yet calibratedCausal:conditional· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIt may state two separate claims as one.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“However, as with all cross- sectional studies, only associations between school start times and other variables can be shown—not cause and effect.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Types of School Start Time Studies
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes✗ Load-bearing: fails✓ Based: passesProbably not a substantial claim. The paper’s conclusions may not depend on it.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“However, class grading and subsequently grade point averages are not standardized and may vary by subject, teacher, and school.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > BACKGROUND
Strength:hedged· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes✗ Load-bearing: fails✗ Based: failsProbably not a substantial claim. The paper’s conclusions may not depend on it. The paper may give no reason why it holds. It may state two separate claims as one.
In the paper
“In 2014, the American Academy of Pediatrics published a policy statement urging middle and high schools to adjust start times to permit students to obtain adequate sleep and improve physical and mental health, safety, academic performance, and quality of life.3”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > BACKGROUND
What the sources say
- Not checked — no full text of the sourcecites [3] source
Strength:plain· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes✗ Load-bearing: fails✓ Based: passesProbably not a substantial claim. The paper’s conclusions may not depend on it.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“That study also did not adjust by sex of student, which was a strong predictor of grade point average.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > BACKGROUND
Strength:boosted· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIt may state two separate claims as one.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“Although longitudinal studies may provide stronger evidence of causation than cross-sectional studies by addressing the issue of temporality, it is”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Types of School Start Time Studies
Strength:hedged· not yet calibratedCausal:conditional· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes✗ Load-bearing: fails✓ Based: passesProbably not a substantial claim. The paper’s conclusions may not depend on it.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“Publication bias and over-representation of studies with significant results is also possible, however, some studies included in this review had results that did not agree with the majority.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Methods
Strength:hedged· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes✗ Load-bearing: fails✓ Based: passesProbably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“Other school characteristics, such as socioeconomic status of students, can also have effects on sleep and other outcomes but is often not reported.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Types of School Start Time Studies
Strength:plain· not yet calibratedCausal:conditional· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes✗ Load-bearing: fails✓ Based: passesProbably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.
In the paper
“In the Norwegian study,78 start times were delayed from 8:30 AM to 9:30 AM on Mondays only.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
What the sources say
- Not checked — no full text of the sourcecites [78] source
Strength:plain· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes✗ Load-bearing: fails✓ Based: passesProbably not a substantial claim. The paper’s conclusions may not depend on it.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Both of these results indicate sleep-deficiency.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
Strength:hedged· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIt may state two separate claims as one.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The lack of association could have been due to either the change being in effect only one day a week or the earlier start time already being late enough.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
Strength:hedged· not yet calibratedCausal:conditional· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes✗ Load-bearing: fails✓ Based: passesProbably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.
In the paper
“the schools in the Croatian study alternated their schedule weekly, with schools starting in the morning one week and in the afternoon the next.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
What the sources say
- Not matchedcites [80]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
Strength:plain· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes✗ Load-bearing: fails✓ Based: passesProbably not a substantial claim. The paper’s conclusions may not depend on it.
- Not matched
In the paper
“That study found that girls had later chronotype (evening preference) and more sleepiness.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
What the sources say
- Not matchedcites [80]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIt may state two separate claims as one.
- Not matched
In the paper
“In the Croatian study,80 the students at the earlier starting schools were predominantly boys, while girls made up most of the population at the later starting schools.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
What the sources say
- Not matchedcites [80]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIt may state two separate claims as one.
- Not matched
In the paper
“However, in addition to the difference in the make-up of the student populations (more boys at earlier schools and more girls at later schools) in that study, students were also aware of the school schedule at enrollment and the response rate was low.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Academics and Cognition
What the sources say
- Not matchedcites [80]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
Load-bearingStrength:plain· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes✓ Load-bearing: passes✓ Based: passesIt may state two separate claims as one.
- Not matched
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“which could be interpreted as a decrease in “catch-up” sleep.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
Strength:hedged· not yet calibratedCausal:conditional· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes✗ Load-bearing: fails✓ Based: passesProbably not a substantial claim. The paper’s conclusions may not depend on it.
- Rests on an assumption: A gap between school-night and weekend sleep can signal that students are not getting enough sleep on school nights and are compensating on weekends.
In the paper
“However, the difference between weeknight and weekend sleep was not analyzed.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
What the sources say
- Not checked — no full text of the sourcecites [67] source
Strength:plain· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes✗ Load-bearing: fails✓ Based: passesProbably not a substantial claim. The paper’s conclusions may not depend on it.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“presumably in an attempt to make up for insufficient nighttime sleep.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Sleep and Sleepiness
Strength:hedged· not yet calibratedCausal:conditional· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes✗ Load-bearing: fails✗ Based: failsProbably not a substantial claim. The paper’s conclusions may not depend on it. The paper may give no reason why it holds.
In the paper
“However, in that study, the start time was delayed on Mondays only.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Depression
What the sources say
- Not checked — no full text of the sourcecites [78] source
Strength:plain· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes✗ Load-bearing: fails✓ Based: passesProbably not a substantial claim. The paper’s conclusions may not depend on it.
In the paper
“However, the start time study was cross-sectional and other variables such as socioeconomic status may explain the difference in time spent at work.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Other Outcomes
What the sources say
- Not matchedcites [60]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
Strength:hedged· not yet calibratedCausal:conditional· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes? Load-bearing: unclear✓ Based: passesIt may state two separate claims as one.
- Not matched
None of the sources cited for this claim have been checked yet.
In the paper
“there is also evidence of a causal relationship between insufficient sleep and depression, as well as mood in general.84,85”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Depression
What the sources say
- Not checked — no full text of the sourcecites [84] source
- Not matchedcites [85]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
Tests✓ Asserted: passes✓ Checkable: passes✓ Load-bearing: passes✓ Based: passesIt may state two separate claims as one.
In the paper
“Incidentally, shorter REM sleep latency, such as was observed by Carskadon and colleagues after an advance in start time,62 is also often observed in major depression.86”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Depression
What the sources say
- Not checked — no full text of the sourcecites [86] source
Strength:plain· not yet calibratedCausal:correlational· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes✗ Load-bearing: fails✓ Based: passesProbably not a substantial claim. The paper’s conclusions may not depend on it.
In the paper
“The report also noted that the attendance reporting procedures changed during the course of the study.”
§ School Start Times, Sleep, Behavioral, Health, and Academic Outcomes: a Review of the Literature > LITERATURE REVIEW > Attendance/Tardiness
What the sources say
- Not matchedcites [81]
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
Strength:plain· not yet calibratedTests✓ Asserted: passes✓ Checkable: passes✗ Load-bearing: fails✓ Based: passesProbably not a substantial claim. The paper’s conclusions may not depend on it.
- Not matched
The paper relies on this without support.
The adverse outcomes linked to insufficient sleep are caused by insufficient sleep, so increasing sleep through later school start times would improve those outcomes.
“Delaying school start times for adolescents has been proposed as a policy change to address insufficient sleep in this population and potentially to improve students’ academic performance, reduce engagement in risk behaviors, and improve health.”
The paper relies on this without support.
The 38 reviewed reports are sufficiently comparable in design, measures, and populations to be synthesized into general conclusions about school start times.
“This paper reviews 38 reports examining the association between school start times, sleep, and other outcomes among adolescent students.”
The paper relies on this without support.
A gap between school-night and weekend sleep can signal that students are not getting enough sleep on school nights and are compensating on weekends.
“Differences in sleep patterns between weeknights and weekend nights can also indicate insufficient weeknight sleep as students try to make up for lost sleep on the weekends.”
The paper relies on this without support.
Adolescents who are sleepy might use caffeine to counteract their sleepiness.
“Sleepy adolescents may also attempt to lessen sleepiness with caffeine.”
The paper relies on this without support.
Grades are not standardized and differ across subjects, teachers, and schools.
“Class grading is not standardized and varies by subject, teacher, and school.”
The paper relies on this without support.
Not all students take standardized tests like the SAT or ACT, and those who do are more likely to be college-bound.
“Standardized tests such as the Scholastic Aptitude Test or the ACT are not taken by all students and are more likely to be taken by students planning to attend college.”
The paper relies on this without support.
Students who already perform very well before a start time delay have little room to improve.
“Finally, students with very good academic performance before a delay in school start time do not have much room for improvement.”
The paper relies on this without support.
Attendance matters for academic success.
“School attendance is also important for academic success.”
The paper relies on this without support.
Biological changes begin before high school.
“Much of the focus has been on high school students, but biological changes begin earlier, so further research into middle-school students is warranted.”
The paper relies on this without support.
Adolescents as a group are largely sleep-deprived.
“Delaying school start times for adolescents has been proposed as a policy change to address insufficient sleep among adolescents, a largely sleep-deprived population”
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
The source backs part of the claim, not all of it — or backs it for a different population, condition or comparison.
In the citing paper
“Several studies have also examined the effect of later start times on car crash and unintentional injury rates among adolescents and found that delayed start times and receiving more sleep as a result may lead to fewer car crash rates and unintentional injury [68,107], most likely through reduced sleepiness [68, 70, 73, 76, 77•, 78•, 79, 80].”
From Later School Start Times as a Public Health Intervention to Promote Sleep Health in Adolescents (2023) · cites this paper as [68]
Experimental — accuracy not yet measuredThe source backs part of the claim, not all of it — or backs it for a different population, condition or comparison.
In the citing paper
“The associations between later school start times and academic performance may be mediated by reduced sleepiness [68, 70, 73, 76, 77•, 78•, 79, 80] and improved attention during the school day [88], particularly among high school students [76].”
From Later School Start Times as a Public Health Intervention to Promote Sleep Health in Adolescents (2023) · cites this paper as [68]
Experimental — accuracy not yet measuredThe cited source says what the claim attributes to it.
In the citing paper
“Growing evidence suggests that adolescents at later-starting schools sleep longer on weekdays, have higher attendance and graduation rates, and fewer mental health symptoms compared to their peers at earlier-starting schools.”
From Later School Start Times as a Public Health Intervention to Promote Sleep Health in Adolescents (2023) · cites this paper as [68]
The cited source says what the claim attributes to it.
In the citing paper
“a review of school start time studies by Wheaton et al. found less reported daytime sleepiness or falling asleep in class in schools with later start times in 10 out of 12 reviewed studies [68].”
From Later School Start Times as a Public Health Intervention to Promote Sleep Health in Adolescents (2023) · cites this paper as [68]
The check wasn’t confident either way, so it gives no verdict — never disputed.
In the citing paper
“the preliminary findings show better dietary quality and more healthful weight behaviors of students attending delayed-start schools compared to their peers [68,105,106].”
From Later School Start Times as a Public Health Intervention to Promote Sleep Health in Adolescents (2023) · cites this paper as [68]
Experimental — accuracy not yet measured
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
Each contradiction between two passages listed here was confirmed by an independent check.
Conclusion claims no negative academic effects, but body text reports worse academics in one study
MajorThe conclusion says later start times never harmed academic performance. Elsewhere, the review says one study found students at earlier-starting schools performed better academically than those at later-starting schools, which contradicts that blanket statement.
“Although not all studies found that later start times corresponded to improved academic performance, no studies found a negative impact of later school start times on academics.”
“In Milic et al.’s study in Croatia, students with an earlier school start time performed better academically than students at the schools with later start times.80”
Academic conclusion overlooks a contrary finding
MajorThe review describes a study in which students at earlier-starting schools performed better academically, but its conclusion says no study found a negative academic result for later starts.
“no studies found a negative impact of later school start times on academics.”
“In Milic et al.’s study in Croatia, students with an earlier school start time performed better academically than students at the schools with later start times.”
Reference-list count conflicts with the reports named
MinorThe methods say that references 50-54 and 55-59 were identified through reference lists, and that Step E added another report. That is more than the five reports later said to have been identified this way.
“Several of the earliest studies with results presented in abstract form only were identified in this manner,50–54 as were some studies from the education or economics literature that were not indexed by PubMed.55–59”
“Five of the 38 reports were identified in this manner.”
Citations
Cites
A New Method for Measuring Daytime Sleepiness: The Epworth Sleepiness Scale
Johns, M. W. (1991) · Sleep · doi:10.1093/sleep/14.6.540 · Cited by 17,364
Subjective and objective sleepiness in the active individual
Åkerstedt, T., & Gillberg, M. (1990) · International Journal of Neuroscience · doi:10.3109/00207459008994241 · Cited by 3,088
Sleep Schedules and Daytime Functioning in Adolescents
Wolfson, A. R., & Carskadon, M. A. (1998) · Child Development · doi:10.1111/j.1467-8624.1998.tb06149.x · Cited by 1,676
Electronic media use and sleep in school-aged children and adolescents: A review
Cain, N., & Gradisar, M. (2010) · Sleep Medicine · doi:10.1016/j.sleep.2010.02.006 · Cited by 1,376
Association between Puberty and Delayed Phase Preference
Carskadon, M. A., Vieira, C., & Acebo, C. (1993) · Sleep · doi:10.1093/sleep/16.3.258 · Cited by 1,167
Sleep, circadian rhythms, and delayed phase in adolescence
Crowley, S. J., Acebo, C., & Carskadon, M. A. (2007) · Sleep Medicine · doi:10.1016/j.sleep.2006.12.002 · Cited by 1,127 · cited 1×
“44 Their natural body clocks can keep adolescents awake until 11 PM or later, in spite of going to bed earlier and good sleep hygiene, such as avoiding stimulating activity at night and minimizing caffeine intake in the afternoon or evening.”
Adolescent Sleep Patterns, Circadian Timing, and Sleepiness at a Transition to Early School Days
Carskadon, M. A., Wolfson, A. R., Acebo, C., Tzischinsky, O., & Seifer, R. (1998) · Sleep · doi:10.1093/sleep/21.8.871 · Cited by 769 · cited 2×
“55,60,65,67 Incidentally, shorter REM sleep latency, such as was observed by Carskadon and colleagues after an advance in start time, 62 is also often observed in major depression.”
Sleepless in Chicago: Tracking the Effects of Adolescent Sleep Loss During the Middle School Years
Fredriksen, K., Rhodes, J., Reddy, R., & Way, N. (2004) · Child Development · doi:10.1111/j.1467-8624.2004.00655.x · Cited by 510 · cited 1×
“30 Finally, students who do not get enough sleep also may be more likely to have problems paying attention and poor academic performance, 17,21,31–36 although not all research agrees.”
Calamaro, C. J., Mason, T. B. A., & Ratcliffe, S. J. (2009) · Pediatrics · doi:10.1542/peds.2008-3641 · Cited by 499
LeBourgeois, M. K., Giannotti, F., Cortesi, F., Wolfson, A. R., & Harsh, J. (2005) · PEDIATRICS · doi:10.1542/peds.2004-0815h · Cited by 491
Flagged first, then by citations
3 of the 91 references couldn’t be matched to a known paper.
Research works printed but not linked: 6
- Allen RP, 1989, Self‐reported sleep‐wake patterns for students during the school year from two different senior high schools, Sleep Res, 21, 114
- Allen RP, 1992, Social factors associated with the amount of school week sleep lag for seniors in a early starting suburban high school, Sleep Res, 21, 114
- Kowalski NA, 1995, School sleep lag is less but persists with a very late starting high school, Sleep Res, 24, 124
- Carskadon MA, 1995, Early school schedules modify adolescent sleepiness, Sleep Res, 24, 92
- Wolfson AR, 1995, Sleep, behavior, and stress at the transition to senior high school, Sleep Res, 24, 115
- Wahlstrom K, 2014, Examining the Impact of Later School Start Times on the Health and Academic Performance of High School Students: a Multi‐Site Study. Center for Applied Research and Educational Improvement
Cited by
Sorted by citations
Altena, E., Baglioni, C., Espie, C. A., Ellis, J., Gavriloff, D., Holzinger, B., Schlarb, A., Frase, L., Jernelöv, S., & Riemann, D. (2020) · Journal of Sleep Research · doi:10.1111/jsr.13052 · Cited by 991
Grandner, M. A. (2017) · Sleep Medicine Clinics · doi:10.1016/j.jsmc.2016.10.012 · Cited by 720
An update on adolescent sleep: New evidence informing the perfect storm model ☆
Crowley, S. J., Wolfson, A. R., Tarokh, L., & Carskadon, M. A. (2018) · Journal of Adolescence · doi:10.1016/j.adolescence.2018.06.001 · Cited by 684
Why Sleep Matters—The Economic Costs of Insufficient Sleep: A Cross-Country Comparative Analysis
Hafner, M., Štěpánek, M., Taylor, J., Troxel, W., & Stolk, C. V. (2016) · Rand health quarterly · doi:10.7249/rhq-06-04-11 · Cited by 633
Sleep in adolescence: Physiology, cognition and mental health
Tarokh, L., Saletin, J. M., & Carskadon, M. A. (2016) · Neuroscience & Biobehavioral Reviews · doi:10.1016/j.neubiorev.2016.08.008 · Cited by 552
Metadata
- Authors
- Wheaton, A. G., Chapman, D. P., & Croft, J. B.
- Affiliations
- Centers for Disease Control and Prevention (US)
- Corresponding author
- Wheaton, Anne G.
- Venue
- Journal of School Health
- Publisher
- Wiley
- Published
- 2016-04-03
- Volume
- 86
- Issue
- 5
- Pages
- 363-381
- ISSN
- 0022-4391 (ISSN-L)
- 1746-1561
- PMC
- PMC4824552
- OpenAlex
- W2318249357
- Cited by
- 311
- References
- 91
- Citations by year
- 2026: 23 · 2025: 29 · 2024: 25 · 2023: 39 · 2022: 42 · 2021: 37 · 2020: 38 · 2019: 28 · 2018: 24 · 2017: 19 · 2016: 7
- FWCI
- 3.41
- Type
- journal article
- Language
- en
- Open access
- green
- www.ncbi.nlm.nih.gov
- Locations
- Journal of School Health (publishedVersion)
- PubMed (publishedVersion)
- PubMed Central (acceptedVersion)
- Funders
- National Institutes of Health (CC999999)
- Topics
- Social Sciences › Psychology › Experimental and Cognitive Psychology › Sleep and related disorders
- Social Sciences › Psychology › Experimental and Cognitive Psychology › Sleep and Work-Related Fatigue
- Life Sciences › Neuroscience › Endocrine and Autonomic Systems › Circadian rhythm and melatonin
- Keywords
- school start time, adolescent sleep, sleep duration, academic performance, school attendance, tardiness, risk-taking, traffic accidents, school policy
- MeSH terms
- Absenteeism, Accidents, Traffic, Adolescent, Child, Cognition, Educational Status, Health Status, Humans, Mental Health, Schools, Sleep, Time Factors, Wakefulness, Young Adult
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
A language model drew the claims from the paper on 2026-09-28, under version 3 of the claim definition (prompt extract-v3).
A second model labelled each claim on 2026-09-28 (model jev-1.13-20260917, definition revision gold-guideline-v0.2).
Cited sources are checked with a language model’s help (gpt-6-sol).
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
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