A 5-year longitudinal study, still in progress, was designed to evaluate the effectiveness of prekindergarten programs in Texas. The components of the study include a statewide survey of school districts, a case study of 10 schools' prekindergarten programs, and a longitudinal study of 2,000 students enrolled in prekindergarten during the 1989-90 school year. Following guidelines established by the National Association for the Education of Young Children (NAEYC), the study seeks to discover: (1) the philosophy of prekindergarten programs; (2) how language development is facilitated in prekindergarten classrooms; (3) how prekindergarten classrooms foster the academic development of limited English proficient students; (4) the nature of the prekindergarten environment; (5) the nature of the parent-prekindergarten program relationship; and (6) the relationship between educational outcomes and participation, or non-participation, in a prekindergarten program. It was found that students who attended prekindergarten programs were less likely to be retained, closer to being on grade level in their oral reading, and perceived by their teachers as being more ready for the next grade when compared to students who did not attend a prekindergarten program. Findings and preliminary recommendations in each of the study's focus areas are provided. (MDM)