The two basic objectives of this five-year study were to investigate a number of variables related to the preparation of effective instructional materials for disadvantaged preschool children, and to determine whether special language instruction would produce improvement in language abilities and thus promote academic progress in the beginning grades. An important by-produce would be a programmed curriculum for the prekindergarten and kindergarten years. The two sections of this report are (1) Report of the Five Year Study, and (2) Comprehensive Evaluation Battery. For Volumes II and III, the total programmed curriculum and the prekindergarten and kindergarten years, see PS 005 702 and 703, respectively. (DB)