The purpose of this proposal was to evaluate two approaches to preschool education using a mobile laboratory as a classroom for rural 4-year-olds. The research data also provide an independent evaluation of the Peabody language development program. Three groups of eight 4-year-old children (N=24) attending the Readimobile Preschool program were matched with controls of the same age, race, sex, and socioeconomic status. Group 1 received a traditional general enrichment curriculum; Group 2 received lessons for 3 months from the Peabody Language Development Kit, Level P; Group 3 received instruction from the Peabody currciulum for 9 months. External evaluations of the three treated and three control groups were used to determine if differences existed among the groups on measures of intelligence, language, cognition, and school readiness. Each child was tested twice to provide information on test reliability on the Stanford-Binet, Caldwell Preschool Inventory, and the Illinois Test of Psycholinguistic Abilities (ITPA). All groups improved their performance on the second administration of the tests. Group 3 surpassed the scores of their controls on the Caldwell and Binet tests. Group 1 performed better than its control group on the ITPA. Group 2's performance did not surpass that of its control group on any measures. Tables and histograms comprise two-thirds of the document. (Author/AJ)