This is a report on an experimental study of a cognitive curriculum supplement developed for the I.V.Y. (Involving the Very Young) Program of the Baltimore City School System. The study concerns the development and transmission of a curriculum for two-year-old children, and an evaluation of its effects. The present version of the curriculum is not a complete one, but a cognitively oriented supplement which seeks to teach the most adaptive style by which representational skills might be used by the two-year-old subjects. Evaluation utilized a design in which 16 preschool centers were paired on a number of relevant variables and randomly assigned to experimental and control groups. Implications of the study are relevant to the general problems of teacher training for preschool programs, the transmission of curricula, and the utility of preschool programs in changing the social and cognitive development of young children. Nine lesson plans are included, as well as the checklists and test batteries used in the evaluation. (Author/ED)