The DOI matches its Crossref record; 70 of the 71 references it cites were found in a registry or an index; 12 of the 36 sources its claims cite were checked for support.
Optimizing distributed practice
Open accessAbstract
More than a century of research shows that increasing the gap between study episodes using the same material can enhance retention, yet little is known about how this so-called distributed practice effect unfolds over nontrivial periods. In two three-session laboratory studies, we examined the effects of gap on retention of foreign vocabulary, facts, and names of visual objects, with test delays up to 6 months. An optimal gap improved final recall by up to 150%. Both studies demonstrated nonmonotonic gap effects: Increases in gap caused test accuracy to initially sharply increase and then gradually decline. These results provide new constraints on theories of spacing and confirm the importance of cumulative reviews to promote retention over meaningful time periods.
Overview
Integrity signals
Registry
Cites
Statistics
Verification
Claims the paper makes
32 Own result · 18 Own interpretation · 13 Own method · 9 No basis given · 7 Partly supported · 4 Sources not found · 3 No full text of the sources · 2 Couldn’t confirm · 2 Not checked yet · 1 Supported · accuracy not yet measured
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“A recent literature review (Cepeda et al., 2006) found just 14 studies that provided comparisons of very short (less than three hours) and long (one day or more) gaps with test delays of one day or more”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > Distributed Practice: Basic Phenomena
What the sources say
- Partly supportedcites Cepeda et al., 2006 sourceExperimental — accuracy not yet measured
The review reports that the literature does not fully represent combinations of inter-study intervals and test delays (Spacing Effects, p. 8), and calls for more studies with educationally relevant intervals (Limitations, p. 14). These passages support the claim that evidence for such comparisons was limited, but our copy does not establish the specific count of 14 studies meeting the stated gap and test-delay thresholds. (LLM, conf=0.78)
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Partly supported
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“In each study, a one-or-more day gap was superior to a very short gap.”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > Distributed Practice: Basic Phenomena
What the sources say
- Partly supportedcites Cepeda et al., 2006 sourceExperimental — accuracy not yet measured
The Educational Implications section (p. 14) supports a benefit from gaps of at least one day for long-term retention, and the Limitations section (p. 14) says multi-day spacing outperforms spacing of a few minutes for long-term retention. The paper does not establish that this comparison favored the longer gap in each of the 14 studies; its lag analysis (p. 8) finds little, if any, effect at retention intervals shorter than one day. (LLM, conf=0.83)
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Partly supported
Every source the paper cites for this claim was checked and supports it.
In the paper
“First, optimal gap increases as a function of test delay.”
- Also stated in: § Additional information · plain
“Optimal gap increases as test delay increases, and the ratio of optimal gap to test delay decreases as test delay increases.”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > General Discussion
What the sources say
- Supportedcites Cepeda et al. (2006) source
The General Discussion (p. 11) states that the optimal inter-study interval increased as the retention interval increased. This directly supports the cited claim that the best gap rises with test delay. (LLM, conf=0.94)
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Also stated in: § Additional information · plain
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“Second, the ratio of optimal gap to test delay appears to decrease as a function of test delay.”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > General Discussion
What the sources say
- Partly supportedcites Cepeda et al. (2006) sourceExperimental — accuracy not yet measured
The General Discussion (p. 11) says that the optimal inter-study interval increases as the retention interval increases. It does not establish the more specific claim that the optimal interval becomes a decreasing fraction of the test delay. (LLM, conf=0.78)
hedgedcorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Partly supported
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“review, as compared to testing with feedback, is a poor way to restudy information (Pashler, Cepeda, Wixted, & Rohrer, 2005).”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > Practical Implications
What the sources say
- Partly supportedcites Pashler, Cepeda, Wixted, & Rohrer, 2005 sourceExperimental — accuracy not yet measured
The Results and Discussion (page unavailable) report that correct-answer feedback after an incorrect response improved one-week retention compared with no feedback. But the paper does not compare testing with feedback against review or restudy, so it does not establish that review is a poor restudy method. (LLM, conf=0.83)
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Partly supported
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Increases in gap beyond a single day produced a small but relatively steady decline in final-test scores, with recall accuracy decreasing just 11% as gap increased from 1 to 14 days.”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > Results and Discussion
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“There was a main effect of gap, F(5,176) = 3.7, p < .005.”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > Results and Discussion
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Recall improved by 34% as gap increased from zero to one day.”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > Results and Discussion
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — 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 studies demonstrated non-monotonic gap effects: Increases in gap caused test accuracy to initially sharply increase and then gradually decline.”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > Abstract
boosteddirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
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 first test of Session 2 measured retention after a single exposure period, and these data therefore show a traditional forgetting function.”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > Results and Discussion
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- It may state two separate claims as one. 27
- Probably not a substantial claim. 15
- The quote only partly states this claim. 2
The cited sources that could be checked couldn’t confirm or dispute this claim.
In the paper
“Including gaps of at least one day insures that the range includes at least one night of sleep, which may play a significant role in memory retention”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > Theoretical Constraints
What the sources say
- Could not verifycites Peigneux, Laureys, Delbeuck, & Maquet, 2001 sourceExperimental — accuracy not yet measured
The indexed copy returns a repository listing and bibliography, but no passage from the paper’s body addressing whether a night of sleep aids memory retention. Searches for post-training sleep, overnight consolidation, and memory retention found no usable body-text passage; the repository abstract is not evidence under this rubric. (LLM, conf=0.70)
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Could not verify
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“The possibility that test accuracy might follow an inverted U-function of gap has been suggested by previous authors”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > INSERT FIGURE 1 ABOUT HERE
What the sources say
- Not matchedcites Balota, Duchek & Paullin, 1989
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- Not checked — no full text of the sourcecites Glenberg, 1976 source
- Partly supportedcites Glenberg & Lehmann, 1980 sourceExperimental — accuracy not yet measured
The Abstract and General Discussion (pages unavailable in our copy) say that recall varies with the gap between repetitions. They describe a proportionality rule: recall increases with spacing when the retention interval is relatively long, but decreases with spacing when it is relatively short. They do not suggest an inverted-U curve with a peak at an intermediate gap. (LLM, conf=0.82)
hedgedcorrelational- Asserted: fails — The authors may not put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The authors may not put it forward as true. The paper’s conclusions may not depend on it.
- Not matched
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“area has had little effect on educational practice (Dempster, 1988(Dempster, , 1989;;Pashler, Rohrer, Cepeda, & Carpenter, 2007).”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > Abstract
What the sources say
- Could not verifycites Dempster, 1988 sourceExperimental — accuracy not yet measured
The cited DOI identifies a horticulture paper, not an education paper, and it is not indexed in Semantic Scholar; its text and abstract were unavailable for verification. A snippet from “Beyond Time-on-Task: The Relationship Between Spaced Study and Certification in MOOCs” says the spacing effect was slow to enter educational practice and cites a Dempster (1988) work, suggesting the citing document may have linked to the wrong Dempster paper. That secondary snippet does not establish that the horticulture paper makes the claim, but the unavailable source text also prevents the definitive check required for a misattribution verdict. (LLM, conf=0.78)
- Could not verifycites Dempster, 1989 sourceExperimental — accuracy not yet measured
The supplied DOI identifies Dempster’s *Theory and Applications of Belief Functions*, a different topic from distributed practice; two searches within that paper returned no snippets supporting the claim. An unscoped snippet in *Beyond Time-on-Task: The Relationship Between Spaced Study and Certification in MOOCs* says the spacing effect was slow to enter educational practice and attributes that observation to Dempster (1988), but its score is only 0.517. This suggests the supplied source is a bibliographic mismatch, but the available evidence does not establish the intended work strongly enough for a misattribution verdict under the specified threshold. (LLM, conf=0.72)
- Supportedcites Pashler, Rohrer, Cepeda, & Carpenter, 2007 source
The passage labeled Abstract says Dempster’s description of the failure to apply spacing research remains apt and reports little evidence that classrooms, instructional texts, or software attend to the temporal distribution of study. (LLM, conf=0.94)
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
- Could not verify
The cited sources that could be checked couldn’t confirm or dispute this claim.
In the paper
“Welborn (1933) used a 28-day test delay, but also omitted feedback from Session 2, implying that the second session probably provided no opportunity for learning those items not learned during Session 1”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > Distributed Practice: Basic Phenomena
What the sources say
- Not matchedcites Welborn (1933)
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- Could not verifycites Pashler, Cepeda, Wixted, & Rohrer, 2005 sourceExperimental — accuracy not yet measured
The Materials and stimuli section says this paper’s own Session 2 occurred about one week later and gave no feedback. Searches for Welborn, 1933, and a 28-day delay found no passage describing Welborn’s study or supporting the inference about its second session. (LLM, conf=0.75)
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Not matched
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“Additionally, Gagné et al. state that distributed practice improves concept learning but we have found no existing studies in the literature that support this claim, and our recent studies fail to support this claim (Pashler, Rohrer, Cepeda, & Carpenter, 2007).”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > Practical Implications
What the sources say
- Partly supportedcites Pashler, Rohrer, Cepeda, & Carpenter, 2007 sourceExperimental — accuracy not yet measured
The section “Spacing in perceptual categorization learning” reports no spacing benefit in the authors’ recent categorization studies, supporting that part of the claim. It says this task is “almost absent” from the spacing literature, not that no existing study supports distributed practice for concept learning. The paper also reports a spacing benefit for learning a mathematical principle, so its negative finding should not be generalized to all concept learning. (LLM, conf=0.85)
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Partly supported
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“An optimal gap improved final recall by up to 150%.”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > Abstract
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Tukey HSD tests show that the zero-day gap produced significantly worse recall than the 1, 2, 4, and 7-day gaps; no other pair-wise comparisons were significant.”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > Results and Discussion
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Likewise, performance on the third and final test of Session 1 showed no main effect or interaction involving gap, although facts showed slightly greater learning than pictures (94 vs. 90%), F(1,155) = 10.3, p < .005.”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > INSERT TABLE 2 ABOUT HERE
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — 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 data from this group are qualitatively and quantitatively consistent with the three-month gap data and the literature more broadly.”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > Additional information
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“At very short test delays, on the order of minutes, the ratio is close to 1.0; at multiday test delays, the ratio is closer to 0.1.”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > General Discussion
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — 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 28-day gap produced 151% greater retention than the 0-day gap, whereas the 1day gap produced only an 18% improvement over the 0-day gap.”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > INSERT TABLE 2 ABOUT HERE
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Second, gap had nonmonotonic effects on final recall even with test delays longer than a week; accuracy first increased and then decreased as gap increased.”
- Also stated in: § INSERT FIGURE 5 ABOUT HERE · boosted
“Studyphase retrieval theories predict -and our data show -an inverted-U shaped function of gap on performance following a test delay.”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > General Discussion
boosteddirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Also stated in: § INSERT FIGURE 5 ABOUT HERE · boosted
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“First-test accuracy ranged from 75 -82% by gap for facts and from 45 -64% by gap for objects.”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > INSERT TABLE 2 ABOUT HERE
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Fits of this function to the data in Experiments 1, 2 (facts), and 2 (objects) produced optimal test scores of 71%, 52%, and 21%, respectively, and optimal gaps of 3.7, 25.6, and 37.1 days, respectively.”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > General Discussion
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Rests on an assumption: The quadratic-in-log-gap function is an adequate description of the relationship between gap and final test score, despite not being theoretically motivated.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“There were main effects of gap, F(5,155) = 8.3, p < .001,and material, F(1,155) = 502.2,p < .001,and an interaction between gap and material, F(5,155) = 4.6, p < .005.”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > INSERT FIGURE 4 ABOUT HERE INSERT TABLE 3 ABOUT HERE
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It 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
“These studies suggest that a gap of roughly one day is optimal, but they hardly demonstrate this claim with any certainty, especially given the restricted set of test delays used.”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > Distributed Practice: Basic Phenomena
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.
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
“(Subjects were not taught to criterion in the second learning session, as they were in the first, because that would have confounded gap and the number of trials required during the second session, as explained in the Introduction.)”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > INSERT FIGURE 2 ABOUT HERE
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. 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
“Few data speak to retention overnight, much less over weeks or months.”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > Abstract
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
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
“Subjects were randomly assigned to one of six conditions (0, 1, 2, 4, 7, or 14 day gap).”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > Materials.
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim.
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
“Because no one has quantitatively characterized the nature of distributed practice functions over time intervals much beyond a day”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > Theoretical Constraints
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: fails — The paper may give no reason why it holds.
Probably not a substantial claim. The paper may give no reason why it holds.
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
“yet little is known about how this socalled distributed practice effect unfolds over nontrivial periods”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > Abstract
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim.
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
“Instead, the present findings, in conjunction with the literature, are consistent with the possibility that the optimal gap increases with test delay, albeit as a declining proportion of test delay.”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > General Discussion
hedgeddirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
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
“For each subject, items that were answered correctly during the pretest were excluded from analysis of their data, leading to the exclusion of less than one percent of items, on average.”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > INSERT TABLE 2 ABOUT HERE
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it. It 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
“Quite dramatically, this demonstrates that a one-day gap is not always optimal, since zero-and one-day gaps were not significantly different, and recall was significantly worse for one-day versus 28-day gaps.”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > INSERT FIGURE 4 ABOUT HERE INSERT TABLE 3 ABOUT HERE
boosted- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It 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
“However, because these four studies and Experiment 1 used approximately equal test delays, the possibility remains that a much longer test delay would yield an optimal gap other than one day.”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > INSERT TABLE 1 ABOUT HERE INSERT FIGURE 3 ABOUT HERE
hedgedconditional- Asserted: fails — The authors may not put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The authors may not put it forward as true.
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
“Table 2 shows fewer subjects in the six-month gap condition, partly due to the increased difficulty maintaining contact with these subjects; otherwise, dropout rates did not vary across conditions.”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > INSERT TABLE 1 ABOUT HERE INSERT FIGURE 3 ABOUT HERE
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.
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
“Subjects in the six-month gap condition were equivalent to other subjects on a wide range of demographic measures.”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > Additional information
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
In the paper
“Morrison et al. (2001) suggest writing facts over and over to learn them; this prescription for massed practice and overlearning is a highly inefficient use of time (Rohrer, Taylor, Pashler, Wixted, & Cepeda, 2005).”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > Practical Implications
What the sources say
- Not matchedcites Rohrer, Taylor, Pashler, Wixted, & Cepeda, 2005
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
boosteddirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Not matched
None of the sources cited for this claim have been checked yet.
In the paper
“Those texts that mention the distributed practice effect often devote a paragraph or less to the topic”
- Also stated in: § Practical Implications · plain
“and offer widely divergent suggestionsmany incorrect -about how long the lag between study sessions ought to be”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > Practical Implications
What the sources say
- Not matchedcites Glaser, 2000
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- Not checked — no full text of the sourcecites Jensen, 1998
- Not matchedcites Ormrod, 1998
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. It may state two separate claims as one.
- Also stated in: § Practical Implications · plain
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
“This suggests that the 28day gap was optimal and supports a claim that final-test recall gradually declines with too-long gaps.”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > INSERT FIGURE 4 ABOUT HERE INSERT TABLE 3 ABOUT HERE
hedgeddirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
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
“Pilot testing confirmed that the options in the multiple-choice test were about equally likely to be chosen by subjects with no previous knowledge of the fact or object.”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > Materials.
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
The quote only partly states this claim.
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
“Subjects were randomly assigned to one of six conditions (0, 1, 7, 28, 84, or 168 day gap).”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > Materials.
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim.
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
“All coding was done blind to experimental condition.”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > INSERT TABLE 2 ABOUT HERE
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it. The quote only partly states this claim.
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 interaction between gap and material likely reflects the different degrees of improvement, relative to baseline, for fact versus visual object materials; there are no obvious qualitative differences in the results.”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > INSERT FIGURE 4 ABOUT HERE INSERT TABLE 3 ABOUT HERE
hedgedcorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
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
“Because pilot data suggested that Swahili-English word pairs (which were used in Experiment 1) would produce floor effects after a 6-month test delay, we chose material that was shown to produce lesser rates of forgetting.”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > INSERT TABLE 1 ABOUT HERE INSERT FIGURE 3 ABOUT HERE
hedgeddirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Rests on an assumption: The material chosen for Experiment 2 produces lesser rates of forgetting than Swahili-English word pairs.
None of the sources cited for this claim could be matched to a paper in Crossref, so there is nothing to check it against.
In the paper
“Both a published encoding variability model (Raaijmakers, 2003) and our own preliminary modeling efforts (Mozer, Cepeda, Pashler, Wixted, & Cepeda, 2008) lend support to this theory.”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > INSERT FIGURE 5 ABOUT HERE
What the sources say
- Not matchedcites Raaijmakers, 2003
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
- Not matchedcites Mozer, Cepeda, Pashler, Wixted, & Cepeda, 2008
Couldn’t be matched to a paper in Crossref, so it can’t be checked.
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
- Not matched
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
“Because we only used a limited range of gaps in the present studies, and the true optimal gap in each of our studies might be slightly shorter or longer than the observed optimal gap, our current data neither support nor refute the existence of a further decreasing ratio, within the multi-day test delay period.”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > Additional information
hedged- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.
The paper relies on this without support.
The laboratory materials and tasks used in the studies are educationally relevant and representative of real-world learning.
“The material was again educationally relevant: Not-well-known facts and names of unfamiliar visually presented objects.”
The paper relies on this without support.
The test delays used (10 days and 6 months) are educationally meaningful.
“when the retention interval was educationally meaningful.”
The paper relies on this without support.
The distributed practice effects observed in these laboratory tasks generalize to real-world educational contexts.
“confirm the importance of cumulative reviews to promote retention over meaningful time periods”
The paper relies on this without support.
The material chosen for Experiment 2 produces lesser rates of forgetting than Swahili-English word pairs.
“we chose material that was shown to produce lesser rates of forgetting.”
The paper relies on this without support.
The facts and objects used in Experiment 2 are not well-known to the subjects.
“a list of 23 notwell-known facts was assembled”
The paper relies on this without support.
The simulated classroom setting is representative of actual classroom learning.
“The experiment was conducted in a simulated classroom setting in a windowless room.”
The paper relies on this without support.
The quadratic-in-log-gap function is an adequate description of the relationship between gap and final test score, despite not being theoretically motivated.
“Although this function is not theoretically motivated, its parameters are meaningful.”
The authors state this as an assumption.
The findings will generalize to classroom settings, at least for learning 'cut and dry' material.
“If these findings generalize to a classroom setting -and we expect they will, at least with regard to learning”
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 cited source says what the claim attributes to it.
In the citing paper
“Also, there is evidence from lab experiments with just one re-exposure that the optimal interstudy interval depends on the retention interval (Cepeda et al., 2009).”
From The Distributed Practice Effect on Classroom Learning: A Meta-Analytic Review of Applied Research (2025) · cites this paper as Cepeda et al., 2009
In the citing paper
“Reactivation of memory traces may constitute an additional temporal substrate that underlies the longest reported effective intervals, on the order of a week71.”
From The right time to learn: Mechanisms and optimization of spaced learning (2016) · cites this paper as [71]
In the citing paper
“For verbal learning with a retention interval of 6 months, a training interval of 7 days was superior to an interval of 3 days71.”
From The right time to learn: Mechanisms and optimization of spaced learning (2016) · cites this paper as [71]
In the citing paper
“For example, in human verbal learning, an interesting positive correlation exists between the length of inter-trial intervals for effective spaced learning and the retention interval (that is, the interval between the final training trial and the test of memory retention).”
From The right time to learn: Mechanisms and optimization of spaced learning (2016) · cites this paper as [71]
In the citing paper
“In humans, a number of cognitive models have been proposed to explain the superiority of spaced training or practice1,30, but no consensus has emerged as to their usefulness or generality31.”
From Computational design of enhanced learning protocols (2012) · cites this paper as [31]
Statistics recomputed
Every reported test result, recomputed from its test statistic and degrees of freedom. A result shows as not adding up only once an independent check has confirmed it.
- ConsistentF(5, 176) = 3.7reported p < .005 · recomputed p = .003
“F(5,176) = 3.7, p < .005”
- ConsistentF(1, 155) = 254.9reported p < .001 · recomputed p < .001
“F(1,155) = 254.9,p < .001”
- ConsistentF(1, 155) = 10.3reported p < .005 · recomputed p = .002
“F(1,155) = 10.3, p < .005”
- ConsistentF(5, 155) = 8.3reported p < .001 · recomputed p < .001
“F(5,155) = 8.3, p < .001”
- ConsistentF(1, 155) = 502.2reported p < .001 · recomputed p < .001
“F(1,155) = 502.2,p < .001”
- ConsistentF(5, 155) = 4.6reported p < .005 · recomputed p < .001
“F(5,155) = 4.6, p < .005”
- ConsistentF(5, 155) = 4.9reported p < .001 · recomputed p < .001
“F(5,155) = 4.9, p < .001”
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
Rated minor: it would not touch a result — a value no result rests on, a p-value that stays on the same side of the significance level, or a conflict that is clerical, resolved elsewhere in the paper, or outside its own findings.
In the paper
“28 84 -0.57-11.3 84 168 0.08 1.6 28 168 -0.25 -4.8 0 28 1.56 25.5 28 168 0.51 -9.8”
§ Running head: DISTRIBUTED PRACTICE OVER MULTI-DAY INTERVALS Optimizing Distributed Practice: Theoretical Analysis and Practical Implications > Additional information
Reported -4.8 · recomputed -9.7
Citations
Cites
(1999) · Cited by 12,812
From dissertation abstracts international
(1974) · ACM SIGGRAPH Computer Graphics · doi:10.1145/988616.988619 · Cited by 12,208
Human Memory: A Proposed System and its Control Processes
Atkinson, R. C., & Shiffrin, R. M. (1968) · Psychology of Learning and Motivation · doi:10.1016/s0079-7421(08)60422-3 · Cited by 7,216
The Psychology of Learning and Motivation: Advances in Research and Theory
(2010) · The Psychology of learning and motivation/The psychology of learning and motivation · doi:10.1016/c2009-0-62209-1 · Cited by 6,035
Principles of Instructional Design
Gagné, R. M., & Briggs, L. J. (1974) · Cited by 4,467
Journal of Experimental Psychology: Human Learning and Memory
Bourne, L. E. (1977) · Cited by 4,328
Learning Theories: An Educational Perspective
Schunk, D. H. (1991) · Cited by 3,725
Memory: A Contribution to Experimental Psychology
Ebbinghaus, H. (2013) · Annals of Neurosciences · doi:10.5214/ans.0972.7531.200408 · Cited by 2,827
(2000) · Cited by 2,779
Advances in Instructional Psychology
(2019) · Routledge eBooks · doi:10.4324/9781315864341 · Cited by 2,538
Bransford, J. D. (2000) · Medical Entomology and Zoology · Cited by 2,322
Distributed practice in verbal recall tasks: A review and quantitative synthesis.
Cepeda, N. J., Pashler, H., Vul, E., Wixted, J. T., & Rohrer, D. (2006) · Psychological Bulletin · doi:10.1037/0033-2909.132.3.354 · Cited by 1,888 · cited 1×
“A recent literature review (Cepeda et al., 2006) found just 14 studies that provided comparisons of very short (less than three hours) and long (one day or more) gaps with test delays of one day or more (Bahrick, 1979; Bahrick & Phelps, 1987; Bloom & Shuell, 1981; Childers & Tomasello, 2002; Fishman, Keller, & Atkinso…”
BackgroundSelf-citationMemory: A contribution to experimental psychology.
Ebbinghaus, H. (1913) · doi:10.1037/10011-000 · Cited by 1,645
Principles of Learning and Memory
Murdock, B. B., & Crowder, R. G. (1977) · The American Journal of Psychology · doi:10.2307/1422060 · Cited by 1,306
The unschooled mind: how children think and how schools should teach
Gardner, H. (1992) · Choice Reviews Online · doi:10.5860/choice.29-4642 · Cited by 1,058
Designing Effective Instruction
Duncan, S. F., & Goddard, H. W. (2017) · Sage eBooks · doi:10.4135/9781071801017.n4 · Cited by 940
(1997) · Cited by 910
(1998) · Cited by 824
Cognitive Psychology and Instruction
Bruning, R. H. (1995) · Cited by 721
A meta-analytic review of the distribution of practice effect: Now you see it, now you don’t
Donovan, J. J., & Radosevich, D. J. (1999) · Journal of Applied Psychology · doi:10.1037/0021-9010.84.5.795 · Cited by 696
Cognitive Psychology and Instruction
(1978) · Springer eBooks · doi:10.1007/978-1-4684-2535-2 · Cited by 540
Training and development handbook: A guide to human resource development
Craig, R. L. (1976) · Medical Entomology and Zoology · Cited by 452
When Does Feedback Facilitate Learning of Words?
Pashler, H., Cepeda, N. J., Wixted, J. T., & Rohrer, D. (2005) · Journal of Experimental Psychology: Learning, Memory, and Cognition · doi:10.1037/0278-7393.31.1.3 · Cited by 445
Self-citationComponent-levels theory of the effects of spacing of repetitions on recall and recognition
Glenberg, A. M. (1979) · Memory & Cognition · doi:10.3758/bf03197590 · Cited by 444
The spacing effect: A case study in the failure to apply the results of psychological research.
Dempster, F. N. (1988) · American Psychologist · doi:10.1037/0003-066x.43.8.627 · Cited by 439
Mastering the instructional design process a systematic approach
Rothwell, W. J., & Kazanas, H. C. 1. (1992) · Cited by 369
Sleeping brain, learning brain. The role of sleep for memory systems
Peigneux, P., Laureys, S., Delbeuck, X., & Maquet, P. (2001) · Neuroreport · doi:10.1097/00001756-200112210-00001 · Cited by 347
Maintenance of Foreign Language Vocabulary and the Spacing Effect
Bahrick, H. P., Bahrick, L. E., Bahrick, A. S., & Bahrick, P. E. (1993) · Psychological Science · doi:10.1111/j.1467-9280.1993.tb00571.x · Cited by 334
Maintenance of knowledge: Questions about memory we forgot to ask.
Bahrick, H. P. (1979) · Journal of Experimental Psychology: General · doi:10.1037/0096-3445.108.3.296 · Cited by 325
Spitzer, H. F. (1939) · Journal of Educational Psychology · doi:10.1037/h0063404 · Cited by 306
Enhancing learning and retarding forgetting: Choices and consequences
Pashler, H., Rohrer, D., Cepeda, N. J., & Carpenter, S. K. (2007) · Psychonomic Bulletin & Review · doi:10.3758/bf03194050 · Cited by 282
Self-citationMonotonic and nonmonotonic lag effects in paired-associate and recognition memory paradigms
Glenberg, A. M. (1976) · Journal of Verbal Learning and Verbal Behavior · doi:10.1016/s0022-5371(76)90002-5 · Cited by 275
Janiszewski, C., Noel, H., & Sawyer, A. G. (2003) · Journal of Consumer Research · doi:10.1086/374692 · Cited by 268
Childers, J. B., & Tomasello, M. (2002) · Developmental Psychology · doi:10.1037/0012-1649.38.6.967 · Cited by 259
Educational Psychology Developing Learners
Ormrod (2004) · Cited by 254
Statistical theory of distributional phenomena in learning
Estes, W. K. (1955) · Psychological Review · doi:10.1037/h0046888 · Cited by 246
Spacing effects and their implications for theory and practice
Dempster, F. N. (1989) · Educational Psychology Review · doi:10.1007/bf01320097 · Cited by 244
Bloom, K. C., & Shuell, T. J. (1981) · The Journal of Educational Research · doi:10.1080/00220671.1981.10885317 · Cited by 243
Retention of Spanish vocabulary over 8 years.
Bahrick, H. P., & Phelphs, E. (1987) · Journal of Experimental Psychology: Learning, Memory, and Cognition · doi:10.1037/0278-7393.13.2.344 · Cited by 228
Application of a Model to Paired-Associate Learning
Bower, G. H. (1961) · Psychometrika · doi:10.1007/bf02289796 · Cited by 209
Spacing and repetition effects in human memory: application of the SAM model
Raaijmakers, J. G. W. (2003) · Cognitive Science · doi:10.1016/s0364-0213(03)00007-7 · Cited by 185
Spacing repetitions over 1 week
Glenberg, A. M., & Lehmann, T. S. (1980) · Memory & Cognition · doi:10.3758/bf03213772 · Cited by 151
Advances in Instructional Psychology. Vol. 1
Frase, L. T., & Glaser, R. (1980) · The American Journal of Psychology · doi:10.2307/1422240 · Cited by 137
Spacing judgments as an index of study-phase retrieval.
Hintzman, D. L., Summers, J. J., & Block, R. A. (1975) · Journal of Experimental Psychology Human Learning & Memory · doi:10.1037/0278-7393.1.1.31 · Cited by 121
Effect of spacing presentations on retention of a paired associate over short intervals.
Peterson, L. R., Wampler, R., Kirkpatrick, M., & Saltzman, D. (1963) · Journal of Experimental Psychology · doi:10.1037/h0046694 · Cited by 117
The ASTD training and development handbook: a guide to human resource development
(1997) · Choice Reviews Online · doi:10.5860/choice.34-2833 · Cited by 101
The effect of overlearning on long‐term retention
Rohrer, D., Taylor, K., Pashler, H., Wixted, J. T., & Cepeda, N. J. (2004) · Applied Cognitive Psychology · doi:10.1002/acp.1083 · Cited by 100
Self-citationAge-related differences in the impact of spacing, lag, and retention interval.
Balota, D. A., Duchek, J. M., & Paullin, R. (1989) · Psychology and Aging · doi:10.1037//0882-7974.4.1.3 · Cited by 92
Designing effective instruction
Anglin, G. J. (2002) · Educational Technology Research and Development · doi:10.1007/bf02504995 · Cited by 87
Massed versus distributed practice in computerized spelling drills.
Fishman, E. J., Keller, L., & Atkinson, R. C. (1968) · Journal of Educational Psychology · doi:10.1037/h0020055 · Cited by 65
Finkenbinder, E. O. (1913) · The American Journal of Psychology · doi:10.2307/1413271 · Cited by 52
Keppel, G. (1964) · Journal of Verbal Learning and Verbal Behavior · doi:10.1016/s0022-5371(64)80027-x · Cited by 48
THE EFFECTS OF PICTURES ON LEARNING TO READ
Harzem, P., Lee, I., & Miles, T. R. (1976) · British Journal of Educational Psychology · doi:10.1111/j.2044-8279.1976.tb02328.x · Cited by 45
Spacing and repetition effects in human memory
van Winsum-Westra, M. (1990) · Radboud Repository (Radboud University) · Cited by 37
The curve of forgetting for advertising material.
Burtt, H. E., & Dobell, E. M. (1925) · Journal of Applied Psychology · doi:10.1037/h0073966 · Cited by 31
What do Zielske's Real Data Really Show about Pulsing?
Simon, J. L. (1979) · Journal of Marketing Research · doi:10.1177/002224377901600315 · Cited by 29
Class results with spaced and unspaced memorizing.
Gordon, K. (1925) · Journal of Experimental Psychology · doi:10.1037/h0064623 · Cited by 28
Piskurich, G. M., Beckschi, P. F., & Hall, B. (2000) · McGraw-Hill eBooks · Cited by 28
Moss, V. D. (2021) · Digital Commons - USU (Utah State University) · doi:10.26076/92f1-7957 · Cited by 23
The effects of repetition in advertising : a field experiment
Strong, E. C. (1972) · University Microfilms International eBooks · Cited by 17
The Relative Efficiencies of Distributed and Concentrated Study in Memorizing.
Robinson, E. S. (1921) · Journal of Experimental Psychology · doi:10.1037/h0073490 · Cited by 17
Degree of learning, interpolated tests, and rate of forgetting
Rose, R. J. (1992) · Memory & Cognition · doi:10.3758/bf03202712 · Cited by 17
The factors affecting a permanent impression developed through repetition.
Strong, E. K. (1916) · Journal of Experimental Psychology · doi:10.1037/h0074989 · Cited by 17
The distribution of time in learning small amounts of material.
Edwards, A. S. (1917) · Studies in psychology contributed by colleagues and former students of Edward Bradford Titchener. · doi:10.1037/11008-012 · Cited by 17
What Do Zielske's Real Data Really Show about Pulsing?
Simon, J. L. (1979) · Journal of Marketing Research · doi:10.2307/3150717 · Cited by 10
Distribution of Practice and Retroactive Inhibition in Free-Recall Learning
Shuell, T. J. (1981) · The Psychological Record · doi:10.1007/bf03394771 · Cited by 7
The long-term neglect of long-term memory: Reasons and remedies.
Bahrick, H. P. (2005) · Experimental cognitive psychology and its applications. · doi:10.1037/10895-007 · Cited by 7
Our knowledge concerning memory.
Ebbinghaus, H. (2004) · Teachers College Press eBooks · doi:10.1037/10011-001 · Cited by 7
Response Availability as a Function of Massed and Distributed Practice and List Differentiation
Watts, D., & Chatfield, D. C. (1976) · The Psychological Record · doi:10.1007/bf03394414 · Cited by 5
Ausubel (1966) · doi:10.1002/1520-6807(196607)3:3
Research works printed but not linked: 7
- Dempster F. N., 1993, Journal of Instructional Psychology, 20, 197
- Jost A., 1897, Zeitschrift für Psychologie und Physiologie der Sinnesorgane, 14, 436
- Moss V. D., 1995, Dissertation Abstracts International, 56, 5204
- Murray J. T., 1983, Dissertation Abstracts International, 43, 3058
- Smith P. L., 1999, Instructional design
- Strong E. C., 1973, Dissertation Abstracts International, 33, 4615
- Welborn E. L., 1933, I. U. School of Education Bulletin, 10, 12
Cited by
Sorted by citations
Dunlosky, J., Rawson, K. A., Marsh, E. J., Nathan, M. J., & Willingham, D. T. (2013) · Psychological Science in the Public Interest · doi:10.1177/1529100612453266 · Cited by 3,138
Spacing Effects in Learning: A Temporal Ridgeline of Optimal Retention
Cepeda, N. J., Vul, E., Rohrer, D., Wixted, J. T., & Pashler, H. (2008) · Psychological Science · doi:10.1111/j.1467-9280.2008.02209.x · Cited by 631
Self-citationCarpenter, S. K., Cepeda, N. J., Rohrer, D., Kang, S. H. K., & Pashler, H. (2012) · Educational Psychology Review · doi:10.1007/s10648-012-9205-z · Cited by 469
“However, reviews of the literature on spacing have revealed that an increase in the duration of the spacing gap does not always produce superior memory retention (e.g., Cepeda et al., 2009; Cepeda et al., 2006; Donovan & Radosevich, 1999; Glenberg, 1976; Verkoeijen, Rikers, & Özsoy, 2008).”
BackgroundSelf-citationSpaced Repetition Promotes Efficient and Effective Learning: Policy Implications for Instruction
Kang, S. H. K. (2016) · Policy Insights from the Behavioral and Brain Sciences · doi:10.1177/2372732215624708 · Cited by 408
“This phenomenon is called the spacing effect (sometimes also referred to as the benefit of distributed practice) and was first observed by researchers over a century ago (Ebbinghaus, 1885/1913).”
BackgroundGreater Neural Pattern Similarity Across Repetitions Is Associated with Better Memory
Xue, G., Dong, Q., Chen, C., Lu, Z., Mumford, J. A., & Poldrack, R. A. (2010) · Science · doi:10.1126/science.1193125 · Cited by 383
Metadata
- Authors
- Cepeda, N. J., Coburn, N., Rohrer, D., Wixted, J. T., Mozer, M. C., & Pashler, H.
- Affiliations
- York University (CA)
- University of California San Diego (US)
- University of South Florida (US)
- University of Colorado Boulder (US)
- Venue
- Experimental Psychology
- Publisher
- Hogrefe Publishing Group
- Published
- 2009-01
- Volume
- 56
- Issue
- 4
- Pages
- 236-246
- ISSN
- 0949-3964 (ISSN-L)
- 1618-3169
- 2190-5142
- OpenAlex
- W1527475029
- Cited by
- 296
- References
- 71
- Citations by year
- 2026: 9 · 2025: 19 · 2024: 20 · 2023: 18 · 2022: 26 · 2021: 23 · 2020: 25 · 2019: 15 · 2018: 15 · 2017: 15 · 2016: 17 · 2015: 19 · 2014: 22 · 2013: 20 · 2012: 12
- FWCI
- 5.00
- Type
- journal article
- Language
- en
- Open access
- green
- escholarship.org
- Locations
- Experimental Psychology (formerly Zeitschrift für Experimentelle Psychologie) (publishedVersion)
- PubMed (publishedVersion)
- eScholarship (California Digital Library) (submittedVersion)
- Digital Commons - University of South Florida (University of South Florida) (submittedVersion)
- Funders
- National Science Foundation (0542013, 0720375)
- U.S. Department of Education
- Institute of Education Sciences
- University of California, San Diego
- Topics
- Life Sciences › Neuroscience › Cognitive Neuroscience › Memory Processes and Influences
- Social Sciences › Psychology › Developmental and Educational Psychology › Second Language Acquisition and Learning
- Social Sciences › Psychology › Experimental and Cognitive Psychology › Visual and Cognitive Learning Processes
- Keywords
- distributed practice, spacing effect, retention, foreign words, factual memory, object naming, long-term recall
- MeSH terms
- Attention, Humans, Memory, Short-Term, Paired-Associate Learning, Pattern Recognition, Visual, Practice, Psychological, Reading, Retention, Psychology, Speech Perception, Vocabulary, Multilingualism, Feedback, Psychological
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 (model deepseek-v4.1-flash, 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 ›
Are you an author, or do you see a problem with this page? Request a review
