The Children's Television Workshop (CTW), responsible for the programs "Sesame Street" and "The Electric Company", conducted extensive research into the systematic use of television to promote the social, emotional, and intellectual growth of young children. Working without precedents in the field of formative research practice, CTW was able to establish an operational model that included behavioral goals, competence testing, experimental production and the Writer's Notebook, a valuable asset emphasizing psychological processes, the child's experimental referents, and unbiased suggestions from the program itself. The subsequent Model for Research on Presentational Learning investigated the relationship between program attributes (appeal, comprehensibility, activity eliciting potential) and the internal compatibility of elements and "viewer outcomes". CTW found that this formative research approach was compatible with the trend toward explicit definition of instructional objectives followed by systematic trial and revision of instructional systems for achieving them. (MC)