The characteristics of effective or successful individualized instructional programs were investigated. The work of other evaluators was reviewed and a series of screening criteria were applied in order to identify effective programs. Programs were selected from evaluation reports for their effectiveness and their "popularity." Information about these programs was then obtained, coded, and used to analyze and synthesize findings. On both theoretical and operational levels, successful programs, including written instructional objectives, frequent diagnosis of student learning needs, provision of instruction five times per successful programs, including written instructional objectives, frequent diagnosis of student learning needs, provision of instruction five times per week, self-pacing, the use of a variety of instructional materials, small group or independent study, and small class size. Some instructional features often considered necessary for individualization were not found to be essential, such as small class size, certain grouping patterns, or written individual plans. Assessment procedures were generally commercial, norm-referenced, standardized achievement tests. No highly informative literature was found on the appropriateness of standardized tests or criterion referenced tests for the evaluation of individualized programs. Descriptions of eleven evaluation reports, a list of successful programs, data collection sheets, and a number of tables are appended. (Author/BW)