Significant cases of research in terms of their effect on school practices have been extensively documented by educational researchers. This booklet summarizes nine such studies, which are published in detail in a companion volume ("Impact of Research on Education: Some Case Studies"). These studies have a variety reasonably characteristic of educational research. In presenting the various case studies, the authors have not focused on the scientific validity of the ideas they present but on the impact of these ideas on educational practice. Essays are written, individually and collaboratively, by the following authors: (1) John B. Carroll; 2) Geraldine Joncich Clifford; (3) Robert Glaser; (4) Guy J. Groen; (5) Hermine Warren; (6) Patrick Suppes; (7) H. H. Stern; (8) Marjorie Bingham Wesche; (9) Birgit Harley; (10) J. W. Getzels; (11) Torsten Husen; (12) Marvin Bressler; and (13) Joel S. Berke. (JD)