Invited commentary: Examining patterns of development in early elementary school using ECLS‐K data

Longitudinal studies grow increasingly useful over time as data accumulate and patterns of individual development are illuminated. This is illustrated by the most recent National Center for Education Statistics (NCES) report on the Early Childhood Longitudinal Study, Kindergarten Class of 1998–99 (ECLS-K), From Kindergarten Through Third Grade: Children’s Beginning School Experiences, which reports findings from the fifth wave of data collected, in spring 2002—when most students were in the third grade—on the schooling experiences and achievement patterns of a cohort of 1998–99 kindergarten students.