Studies suggest that developmental students like peer tutoring, are more relaxed with peers, and feel that peer tutoring helps their grades. However, the small number of studies on college tutoring provides no consistent evidence that underprepared students who are tutored improve either their grades or grade point averages. The students who do earn higher grades after tutoring tend to be better prepared to begin with, have higher ability and/or more experience in college--there is no consistent evidence that tutoring helps the weakest students. Research does suggest, however, that underprepared students who were tutored remained in college longer than comparable students who were not tutored. Experts also agree about what constitutes a successful program; at a minimum, tutors are recommended by a faculty member, carefully screened, trained how to work with underprepared students before they start tutoring, and evaluated regularly by their coordinators, instructors, and their students. The dearth of research on tutoring may result from a lack of research skills among tutor coordinators; a lack of money, time and resources; the difficulty in comparing results from various kinds of tutoring; or other causes. However, as college tutoring programs adopt standards and better programs, researchers should examine the questions of whether, how, and to what extent tutoring can help underprepared students. A 39-item bibliography is included. (GFW)