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Preschool: First Findings From the Third Follow-up of the Early Childhood Longitudinal Study, Birth Cohort (ECLS-B)
NCES 2008-025
October 2007


The Early Childhood Longitudinal Study, Birth Cohort (ECLS-B) is designed to provide detailed information on children's development, health, and early learning experiences in the years leading up to entry into school. The ECLS-B is the first nationally representative study within the United States to directly assess children's early mental and physical development, the quality of their early care and education settings, and the contributions of their fathers, as well as their mothers, in their lives. The children participating in the ECLS-B are followed from birth through kindergarten entry. To date, information has been collected from children and their parents during three rounds of data collection, conducted when the children were about 9 months of age (2001), about 2 years of age (2003), and about preschool age (age 4, 2005). Their experiences are representative of the experiences of the approximately 4 million children born in the United States in 2001. This First Look report provides information on certain characteristics of this population of children when they were about age 4. The information in this report complements that presented in Children Born in 2001: First Results from the Early Childhood Longitudinal Study, Birth Cohort (ECLS-B) (Flanagan and West 2004) and Age 2: Findings From the 2-Year-Old Follow-up of the Early Childhood Longitudinal Study, Birth Cohort (ECLS-B) (Mulligan and Flanagan 2006).

The purpose of this First Look report is to introduce new ECLS-B survey data through the presentation of selected descriptive information. Readers are cautioned not to draw causal inferences based on the univariate and bivariate results presented. It is important to note that many of the variables examined in this report may be related to one another, and complex interactions and relationships among the variables have not been explored. The variables examined here are also just a few of the several thousand that can be examined in these data; they were selected to demonstrate the range of information available from the study. These findings are examples of estimates that can be obtained from the data and are not designed to emphasize any particular issue. The release of this report is intended to encourage more in-depth analysis of the data using more sophisticated statistical methods.

The tables in this report present information collected during the preschool wave of the ECLS-B in the following areas: demographic characteristics of children and their families (table 1); children's language, literacy, mathematics, color knowledge, and fine motor skills (tables 2 through 6); and children's experiences in early care and education (table 7).

Performance on measures of children's language, literacy, mathematics, color knowledge, and children's fine motor skills is sensitive to the age at which the children were assessed. The preschool data collection of the ECLS-B was intended to assess children when the majority of the sample would be about 48 through 57 months of age. However, during the preschool round, children were assessed when they were as young as 44 months and as old as 65 months. Therefore, in this report, the first table on language, literacy, mathematics, color knowledge, and fine motor skills presents information by age at the time of assessment (table 2). For this table, age at assessment is divided into three categories: less than 48 months; 48 through 57 months (roughly the target age for the assessment), and more than 57 months. Because age at assessment is not independent of certain child and family characteristics (certain groups of children may be older when assessed in a given wave)1, it is inappropriate to analyze the ECLS-B cognitive and fine motor information without addressing age at assessment (for more information on this issue please see the Early Childhood Longitudinal Study, Birth Cohort (ECLS-B), Methodology Report for the Preschool Data Collection (2005–06), Volume I: Psychometrics [Najarian, Lennon, and Snow 2007]). Therefore, after a table presenting cognitive and fine motor data by overall age of assessment (table 2), a series of tables (tables 3 through 6) present information on the 75 percent of the children who were assessed in the target age range (48 through 57 months) by certain child and family characteristics. All comparisons made in the text were tested for statistical significance to ensure that the differences were larger than might be expected due to sampling variation. All differences reported are significant at the p<.05 level. Appendix A provides technical documentation for the findings presented in this report, and general information about the study. Appendix B reports the standard errors for tables 1 through 7.


1 Please refer to table A-1 in appendix A of this report.