An examination of research in the field of early childhood language and literacy development reveals substantial changes over the past two decades. Initially, a shift in the conceptualization of what constitutes literacy and when literacy begins resulted in a burgeoning corpus of research that examined children's literate experiences before the beginning of formal schooling. This perspective, termed emergent literacy, brought a new and vigorous focus to the developmental precursors of formal reading that originate in children's early years, thus broadening the scope of research to the years prior to formal schooling, that is, into the early childhood years.
Although research in the field of emergent literacy has been diverse both in topic and methodology, there is currently consensus about the key elements that are foundational to learning to read: oral language, phonological processing, and print awareness (Whitehurst & Lonigan, 2001). Research has provided empirical evidence of the relationships between these early skills and later reading abilities. For example, numerous research studies have demonstrated that early, well-developed oral language skills are a strong predictor of later reading abilities (e.g., ECCRN, 2005; Hart & Risley, 1995; Walker, Greenwood, Hart, & Carta, 1994; Storch & Whitehurst, 2002; Dickinson & Porsche, 2008; Spira, Bracken, & Fischel, 2005; Tabors, Roach, & Snow, 2001). Similarly, children who are sensitive to the sounds in words and are able to manipulate and use them are more likely to be successful in learning to read (Snow, Burns & Griffin, 1998; Pullen & Justice, 2003; Whitehurst & Lonigan, 2001) because these abilities are strongly related to decoding abilities. Finally, in terms of print awareness, studies have shown that a child's knowledge of the alphabet when they enter school is one of the single best predictors of later reading achievement (Snow, Burns & Griffin, 1998; Whitehurst & Lonigan, 2001). The ability to recognize and distinguish individual letters, as well as knowing the sounds of the language, together form the foundation for learning the sound-symbol association.
The importance of successfully mastering these skills for young children cannot be underestimated since limited early literacy skills tend to translate into persistent deficits. For example, Tabors, Snow, & Dickinson (2001) found stability between relative levels of reading performance in kindergarten and seventh grade, while Cunnigham & Stanovich (1997) found the same stability between first grade and the end of high school. Therefore, the effect of poor language and literacy abilities in early childhood can be cumulative, such that children who are behind early on continue to fall further and further behind more skilled readers in reading as well as in other academic areas (Chall, Jacobs, & Baldwin, 1990). Furthermore, evidence indicates that it is very difficult to remedy children's language and literacy difficulties with compensatory programs (McGill-Franzen & Allington, 1991), particularly after third grade (Good, Simmons, & Smith, 1998). Of particular policy relevance is the fact that children of lower socio-economic status are at high risk for reading difficulties. These children tend to begin school with less-developed abilities in the three foundational skills of early literacy than their more economically advantaged peers. Thus, interest in effective interventions to improve children's early language and literacy skills is motivated in large part by the possibility of narrowing the school readiness gap.
One argument for focusing on providing comprehensive support for children's development of early language and literacy skills comes from economists such as Lynch (2004), who have conducted cost-benefit analyses that support the idea that the benefits of substantial investment in early interventions, in terms of increased educational attainment and income earnings outweigh the costs of these investments. Similarly, Reynolds (2005) found that early interventions are the most cost-effective method to make positive contributions to at-risk children's development.
Another argument comes from evidence that most children are able to achieve grade-level reading levels if they receive effective early reading instruction (Clay, 1985; Iverson & Tunmer, 1993; Pinnell, 1989; Snow, Burns, & Griffin, 1998; Wasik & Slavin, 1993). If this is indeed the case, then perhaps it is deficiencies in teachers' instruction, rather than in children's cognitive abilities that explains the large number of reading difficulties in U.S. schools (Dickinson, McCabe, & Clark-Chiarelli, 2004). Although parents are children's first and foremost teachers, more and more children are spending a large portion of their waking hours with adults in early childhood settings. Recent research has lent support for the idea that teachers' instructional practices can make a difference in children's outcomes. For example, Huttenlocher, Vasilyeva, Cymerman & Levine (2002) found a positive association between teachers' use of complex syntax and preschoolers' comprehension of complex syntax. More importantly, they found that classroom input made up for the lack of home input for children from disadvantaged backgrounds.
Thus, based on the benefits of attending to children's deficits in language and literacy before formal schooling, the lack of success remedying these difficulties after school entry, and the high cost of not doing so for later academic achievement, educators and policy makers have turned their attention to the possibilities of improving children's skills early on. Because over half of 3- to 5-year-old children in the United States - 57% in 2005 - spend time in early childhood care and education programs, including day care centers, Head Start programs, preschools, nursery schools, or prekindergartens (U.S. Department of Education, 2006), there has been a focus on reaching the many children who are in these settings.
However, despite substantial investments by federal and state governments in early childhood center-based programs such as Head Start, Even Start and public pre-kindergarten, until recently, little rigorous research had been conducted on the effectiveness of various curricula used to improve children's early language and literacy skills in these programs. It was against this backdrop that the federal government, through various agencies, funded rigorous evaluations of multiple curricula that focused on language and literacy, as well as other important school readiness skills. The Preschool Curriculum Evaluation Research (PCER) and the Interagency School Readiness Consortium (ISRC) consortia are two such federal sources that have provided funding for rigorous evaluations of curricula used in early childhood programs.
This review provides a synthesis of the emerging findings from this set of major federal research initiatives. We examine the evaluations of program enhancements funded through PCER, ISRC, and the Evaluation of Child Care Subsidy Strategies, as well as evaluations of federal early childhood programs National Evaluation of Early Reading First and Head Start Impact Study in terms of key issues in the field of young children's language and literacy development prior to formal schooling. For the PCER interventions, both the cross-site evaluation and individual papers (when available) were reviewed. For the ISRC interventions, the evaluations of which were funded later, there is no cross-site evaluation and most study teams had only reported initial findings in the form of conference presentations rather than journal articles. Therefore, the review of the ISRC interventions should be considered preliminary as findings are still emerging from this work. After synthesizing the set of studies, some possible directions for future research are suggested based on this body of research.
"index.pdf" (pdf, 307.32Kb)
"apa.pdf" (pdf, 78.45Kb)
"apb.pdf" (pdf, 401.85Kb)
"apc.pdf" (pdf, 288.78Kb)
"apd.pdf" (pdf, 90.04Kb)
"ape.pdf" (pdf, 190.7Kb)