A longitudinal investigation of the role of quantity and quality of child-directed speech in vocabulary development.

“While it is acknowledged that some of this variability is likely due to genetics (see Stromswold, 2001, for a review), environmental factors also play an integral role (see Hoff, 2006, for a review).”

“…and quality of language-specific input is a strong determinant of skills in that language (see, Hart and Risley, 1995; Huttenlocher et al., 2002; Rowe, 2012; Grüter and Paradis, 2014), and the distributed nature of bilingual children’s input is thereby one of the most important explanations for…”

“Regarding the effect of input quantity and quality, Rowe (2012) assumes that depending on age, influence differs: While input quantity is more significant in the early stages, with increasing age and cognitive development, diversity becomes more important.”

“…2015; Hoff, 2003; Hurtado, Marchman, & Fernald, 2008; Huttenlocher, Waterfall, Vasilyeva, Vevea, & Hedges, 2010; Pan, Rowe, Singer, & Snow, 2005; Rowe, 2008, 2012; Weisleder & Fernald, 2013), as have the findings that there are SES differences in caregiver speech (Cartmill et al., 2013; Hoff,…”

“The quality of language exposure during shared book reading is also highly relevant to children’s language development; in particular, a varied and complex language input, a high level of decontextualization from the here and now, asking open-ended questions, elaborating on the child’s comments, and interacting in a r…”

“For example, the amount of maternal language input is positively correlated with monolingual children’s lexical knowledge (Hoff, 2003; Hurtado, Marchman, & Fernald, 2008; Rowe, 2008, 2012; Rowe, Raudenbush, & Goldin-Meadow, 2012).”

“…is measured in a variety of ways, including global factors such as parental sensitivity and cognitive stimulation (Leigh et al., 2011; Mistry et al., 2008; Raviv et al., 2004) and interactional factors such as lexical and syntactic diversity (Hoff, 2003; Huttenlocher et al., 2010; Rowe, 2012).”

“The influence of certain interactional characteristics may be specific to particular language or cognitive levels, which change over time (Nelson, Denninger, Bonvillian, Kaplan, & Baker, 1984; Rowe, 2012).”

“Quality variables include the number of word types, syntax, word sophistication (use of rare words), decontextualized language use, and conversational turns that children are exposed to in early childhood.(27) Though much of the literature on the influences on language development in early childhood focuses on either…”

“…in applying these practices, we retained content on describing actions and feelings in the MaPa program, in keeping with compelling scientific evidence that highlights their benefits for children’s cognition and language (Rowe, 2012) and emotional competence (Denham, Renwik-DeBardi, & Hewes, 1994).”

“While there is much work indicating that quantity and diversity of adult linguistic input is important for child language development (Bornstein et al., 2020; d’Apice et al., 2019; Hoff, 2003; Huttenlocher, 1998; Huttenlocher et al., 1991, 2007; Pan et al., 2005; Rowe, 2012; Topping et al., 2013).”

“16 characteristics of the input (Fernald et al., 2012; Hart & Risley, 1995; Hoff, 2013; Rowe, 2012, 2008) were also found on the quantity and distribution of nouns and verbs in children’s everyday linguistic environments.”

“The vast majority of the literature examining the relationship between parental and child vocabulary is focused on the early years, possibly because it is during this period that the greatest challenges are met (Cartmill et al., 2013; Fernald, Marchman, & Weisleder, 2013; Rowe, 2012).”

“For example, a longitudinal study of vocabulary acquisition revealed that input quantity mattered most during the second year of development, whereas input quality was more important during the third year [50].”

“As several researchers have demonstrated, parents’ input has differential effects depending on the stage of children’s vocabulary development, findings that are pertinent to the current study (Hoff & Naigles, 2002; Pan et al., 2005; Rowe, 2012; C. TamisLeMonda et al., 2014; Weizman & Snow, 2001).”

“…input predict language outcomes for both typically developing children (e.g., Hart & Risley, 1995; Hoff, 2003; Huttenlocher, Haight, Bryk, Seltzer, & Lyons, 1991; Rowe, 2012) and children with ASD (e.g., Bang & Nadig, 2015; Flippin & Watson, 2015; Haebig, McDuffie, & Ellis Weismer, 2013).”

“Both book reading (Farrant & Zubrick, 2012; Mol et al., 2008; Richman & Colombo, 2007) and child-directed speech (Rowe, 2012; Weisleder & Fernald, 2013) are positively linked with word knowledge as measured via referent selection.”

“An increasingly robust body of research has tackled the question of how variation in the quantity and quality of input children receive from their caregivers shapes their language learning outcomes (Romeo et al., 2018; Rowe, 2008, 2012; Schwab & LewWilliams, 2016b; Weisleder & Fernald, 2013).”

“In brief, research suggests that high-quality language is: directed at the child and in response to her behaviour, and includes a diversity of words, phrases and sentence structures (Ramírez-Esparza et al., 2014; Rowe, 2012).”

“In a study conducted in the United States, decontextualized talk to preschoolers predicted language outcomes better than did the number of words (Rowe, 2012).”

“Unfortunately, research programs about natural learning environments (e.g., Huttenlocher, Vasilyeva, Cymerman, & Levine, 2002; Huttenlocher, Vasilyeva, Waterfall, Vevea, & Hedges, 2007; Rowe, 2012; Vasilyeva, Waterfall, & Huttenlocher, 2008), learning mechanisms (e.”

“Besides, new words are presented together with children’s ‘known words’, which constrain the possible interpretation of the new word (Rowe 2012).”

“Frequent and elaborative reminiscing in the preschool years predicts children’s later vocabulary, story comprehension, phonological awareness, and print skills (Demir, Rowe, Heller, Goldin-Meadow, & Levine, 2015; Leyva et al., 2012; Neha et al., 2020; Reese, 1995; Rowe, 2012).”

“Research has established that the amount and characteristics of language addressed to children are related to their current and subsequent language development (Bernstein 2000; Hoff 2006; McCartney 1984; NICHD ECCRN 2000; O’Brien and Bi 1995; Rowe 2012; Rudd, Cain, and Saxon 2008; Vernon-Feagans and Bratsch-Hines 2013…”

“developing language skills (Hart & Risley, 1992, 1995; Huttenlocher, Haight, Bryk, Seltzer, & Lyons, 1991; Pan, Rowe, Singer, & Snow, 2005; Rowe, 2012) and there is evidence that mothers who point more also talk more (Rowe, 2000), we wanted to include measures of”

“These distinctions are mirrored in the communicative input to children from varying SES backgrounds (Cartmill et al., 2013; Hart & Risley, 1995; Hoff, 2003; Huttenlocher et al., 2007; Rowe, 2012).”

“…between maternal education and lexical development indicate that greater diversity of vocabulary and structures provided by mothers with higher educational backgrounds leads to gains in children’s total vocabulary (Hoff, 2003; Huttenlocher, Waterfall, Vasilyeva, Vevea, & Hedges, 2010; Rowe, 2012).”

“Past studies have shown that language facilitation strategies such as diverse and rich semantic content (Rowe, 2012), linguistic mapping (Yoder & Warren, 2001), semantic expansion (Scherer & Olswang, 1984), grammatical recasts (Cleave, Becker, Curran, Van Horne, & Fey, 2015), and follow-in comments (McDuffie & Yoder,…”

“Transcribed speech was divided into utterances, defined as any sequence of words preceded and followed by a pause, a change in intonational pattern, or a change in conversational turn (Rowe, 2012; Rowe & Goldin-Meadow, 2009).”

“Here, the field clearly differs not only from L1 acquisition research (e.g. Lieven, 2016; Rowe, 2012), but also from the corpus-based work of (non-SA) SLA researchers such as Dimroth et al. (2013), N Ellis et al. (2016), Eskildsen (e.g. Eskildsen, 2015), Hellermann (2008) or Pujadas and Muñoz…”

“Parents are a key part of a child’s microsystem and influence emotion regulation, executive functioning, language development and social functioning (Barnett et al., 2012; Fay‐Stammbach, et al., 2014; Morris et al., 2007; Rowe, 2012).”

“First, in line with behavioural studies, we predicted that both variety of exposure and quantity would contribute to literacy development (Jones & Rowland, 2017; Ouellette, 2006; Rowe, 2012).”

“Among hearing children, variations in the amount of language children are exposed to and in the proficiency of their language models is directly tied to children’s later language outcomes (Huttenlocher et al. 1991, Rowe 2012, Weisleder & Fernald 2013).”

“, talk about the past or future, and talk involving explanations) in different everyday contexts supports preschool-age children’s vocabulary, syntax, and narrative development (e.g., Demir, Rowe, Heller, Goldin-Meadow, & Levine, 2015; DeTemple, 2001; Dickinson & Smith, 1994; Hindman et al., 2008; Peterson & McCabe, 1…”

“…importance of these factors may be different at the age of 3;0 because it is known that specific factors may support vocabulary development at different ages, and the gap in children’s abilities that is related to different social environments increases over time (Fenson et al., 2007; Rowe, 2012).”

“Indeed, for all children, language is developed through interactions that vary in quantity and quality, and that also vary depending on the context in which the interactions unfold (De Houwer 2007; Hoff 2006, 2010; Hurtado, Marchman, and Fernald 2008; Rowe 2012).”

“For instance, Kurkul et al. (unpublished) found that parents do not often produce spontaneous mechanistic explanations to their children, and observational studies that have measured the frequency of childdirected explanations report similar proportions (Beals, 2001; Rowe, 2012).”

“Among different aspects of cognitive stimulation, parental language input is a strong predictor of child outcomes, over and above parental SES (e.g., Rowe, 2012; Demir et al., 2015).”

“Yet, there is wide variability in input quantity within SES strata (Sperry et al., 2019; Weisleder and Fernald, 2013) and qualitative features of the input were found to be more important than sheer quantity (Rowe, 2012; Rowe and Snow, 2019).”

“Quality and quantity of speech during interactions are also significant factors in language learning, especially the growth of vocabulary [124–127].”

“children than higher SES households [4,9,13,14], as well as engage in less child-directed speech (CDS) [2,15].”

“Frequent reading may potentially close such ‘gaps’ (Krashen, 2004), increasing the quantity (e.g., number of words) and the quality (e.g., which words are used) of children’s language exposure (Rowe, 2012).”

“The diversity of a parent’s vocabulary usage has been linked to language ability in children [6, 29, 31, 58, 67].”

“Rowe. 2014. “A Comparison of Preschool Children’s Discussions with Parents During Picture Book and Chapter Book Reading.” First Language 34 (3) (2014): 205–226.”

“Early vocabulary development is known to be influenced by the lexical diversity in the input, and relatedly, the socio-economic status (SES) of the caregivers (Hart & Risley, 1995; Huttenlocher, Haight, Bryk, Seltzer, & Lyons, 1991; Rowe, 2008; 2012).”

“Scientists who study CDS customarily rely on time-intensive, meticulous processes to hand-transcribe and codify characteristics of CDS to which children are exposed; in turn, researchers seek to precisely represent children’s early language experiences and use this to understand how CDS influences development and the…”

“Importantly, such differences in language exposure are linked to later vocabulary skills (Hoff & Naigles, 2002; Hurtado et al., 2008; Rowe, 2012) and thus represent a foundation for literacy acquisition (Hjetland et al., 2019; Ouellette, 2006).”

“…exposure differences, with reports of young affluent children by 4 years of age hearing on average about 30 million more words than children from less affluent families (Hart and Risley, 1995), with higher lexical diversity and conversational fluency (Huttenlocher et al., 2010; Rowe, 2008, 2012).”

“The current results corroborate previous studies in child language development research (Rowe, 2012) and in L2 research in majority/societal language contexts (Paradis & Jia, 2017) that showed a stronger role of informal L2 contact over structured instructional input.”

“For example, between a child’s second and eighth birthdays, visual scan rates accelerate (De Haan & Johnson, 2005) working memory doubles (Cowan, 2016), speech becomes syntax-rich (Rowe, 2012), and friendships shift from parallel play to negotiated rule-making (Rubin et al., 2006).”

“Furthermore, it could be important to examine additional environmental factors in moderately premature samples, such as maternal intrusiveness [19], paternal behavior [69], and quantity and quality of language input a child receives [70].”

“…(i.e., at earlier or later stages of language development; Adamson et al., 2017; Haebig, McDuffie, & Ellis Weismer, 2013; Hoff & Naigles, 2002; Rowe, 2012), that these subgroupings themselves are related to later outcomes (Tager-Flusberg, 2006), and that distinguishing among groups of…”

“Among typically-developing children, language nutrition has been associated with individual differences in child language skills,(8,9) though the associations vary as a function of the child’s age or stage of language development.(8) Disparities in child language outcomes as a function of socioeconomic status have bee…”