A decade of research on immersion programs in Ontario is synthesized. The immersion programs studied over this period include three major alternatives: early total French immersion, early partial French immersion, and late partial French immersion. The programs all serve an English speaking students population, devote at least one half of each school day to instruction in French, and use the same curriculum content as the regular English program. The specific programs included in this synthesis are described and their effects on French and English language skills, academic outcomes, and social psychological adjustment are summarized. Questions raised by the research involve effective teaching strategies and research design. Overall, the three types of French immersion programs have been successful in promoting advanced French language skills. This success is attributable in part to parental involvement, optional participation, positive attitudes toward French, and the majority group membership of the participants. A bibliography includes a comprehensive listing of reports, articles, and books which relate to immersion education in Canada and the United States. (RW)