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Digest of Education Statistics: 2018
Digest of Education Statistics: 2018

NCES 2020-009
December 2019

Appendix A.2. Early Childhood Longitudinal Study, Kindergarten Class of 1998–99

The Early Childhood Longitudinal Study, Kindergarten Class of 1998–99 (ECLS-K) was designed to provide detailed information on children’s school experiences throughout elementary school and into middle school. The study began in the fall of 1998. A nationally representative sample of about 21,300 children enrolled in 940 kindergarten programs during the 1998–99 school year was selected to participate in the ECLS-K. The children attended both public and private kindergartens and full- and part-day programs. The sample included children from different racial/ethnic and socioeconomic backgrounds and oversamples of Asian and Pacific Islander children and private school kindergartners.

In the kindergarten year (1998–99), base-year data were collected in the fall and spring. In the first-grade year (1999–2000), data were collected again in the fall and spring. In the 3rd-grade (2002), 5th-grade (2004), and 8th-grade (2007) years, data were collected in the spring. The fall 1999 collection drew from a 30 percent subsample of schools; all other collections drew from the full sample of schools.

From kindergarten to 5th grade, the ECLS-K included a direct child cognitive assessment that was administered one on one with each child in the study. The assessment used a computer-assisted personal interview (CAPI) approach and a two-stage adaptive testing methodology. In the 8th grade, a two-stage adaptive paper-and-pencil assessment was administered in small groups. In kindergarten and first grade, the assessment included three cognitive domains: reading, mathematics, and general knowledge. General knowledge was replaced by science in the 3rd, 5th, and 8th grades. Children’s height and weight were measured at each data collection point, and a direct measure of children’s psychomotor development was administered in the fall of the kindergarten year only. In addition to these measures, the ECLS-K collected information about children’s social skills and academic achievement through teacher reports in every grade and through student reports in the 3rd, 5th, and 8th grades.

A computer-assisted telephone interview with the children’s parents/guardians was conducted at each data collection point. Parents/guardians were asked to provide key information about the children in the ECLS-K sample on subjects such as family structure (e.g., household members and composition), family demographics (e.g., family members’ age, relation to the child being studied, and race/ethnicity), parent involvement, home educational activities (e.g., reading to the child), child health, parental education and employment status, and the social skills and behaviors of their children.

Data on the schools that children attended and their classrooms were collected through self-administered questionnaires completed by school administrators and classroom teachers. Administrators provided information about their schools’ populations, programs, and policies. At the classroom level, data were collected from teachers on the composition of the classroom, teaching practices, curriculum, and teacher qualifications and experience. In addition, special education teachers and related services staff provided reports on the services received by children with an Individualized Education Program (IEP).

Further information on the ECLS-K may be obtained from

Gail Mulligan
Jill McCarroll
Longitudinal Surveys Branch
Sample Surveys Division
National Center for Education Statistics
550 12th Street SW
Washington, DC 20202