The objective of this study was to develop and evaluate two procedures for providing preschool education for rural 4-year-olds by using a mobile laboratory. The project used "readimobiles" to determine the effectiveness of a structured, psycholinguistically-based preschool curriculum on black, disadvantaged children. There were three treatment groups: (1) advantaged white children receiving a general enrichment program, (2) disadvantaged black children receiving three months of lessons from the Peabody Language Development Kit, and (3) disadvantaged black children receiving nine months of the Peabody program. Each child in these treatment groups was matched to a control child by age, race, sex, and socioeconomic status. Both groups were posttested twice (to determine reliability) on the Stanford-Binet, the Caldwell Preschool Inventory and the Illinois Test of Psycholinguistic Abilities. The results showed that the experimental subjects were superior to the control subjects on all measures. The treatment groups also differed significantly from one another. Finally, subjects in all groups scored significantly higher on the second posttest. The final report of this document submitted to the Office of Economic Opportunity appeared as ED 039 022. (MH)