This review of the literature examined a number of specific factors as they relate to the persistence and achievement of persons involved in distance learning. These factors are: (1) media of instruction; (2) instructor contact; (3) locus of control; and (4) certain demographic characteristics such as age, gender, income, and educational level. In preparation for the review, a search of a number of databases, including the Educational Resources Information Center (ERIC), Dissertation Abstracts Online (DAO), and Psychological Abstracts, was undertaken using these descriptors: attrition, dropout or persistence in distance education, achievement and performance in distance education, locus of control, instructor support and delivery model and demographic factors impacting distance education. It is clear from the review that the findings regarding the impact of the various factors on educational outcome are mixed due to inconclusive research findings and the lack of generalizability, a finding attributed to the lack of common definitions. (Contains 92 references.) (Author/SLD)