This study examines programs for improving science teaching in the schools of Argentina, Brazil, Lebanon, the Philippines, and Turkey. Appearing in two parts, the first contains five case histories--descriptive and uninterpreted accounts of the events as they have unfolded over time in the programs. The second part of the study compares, analyzes, and interprets the experiences of these programs in a search for the lessons they provide on innovating in science education and on meeting the technical assistance needs that arise in that innovating. (Author/CP)