Over 3,500 commercial programs for use in programed instruction are listed by subject and publisher. For each title or series, the following information is provided: approximate length in hours, approximate length in frames or pages, appropriate level for use, list price, and "other information," which often includes a description of the contents. The 55 subject areas include the liberal arts; technical, vocational, and professional training; and miscellaneous topics like bridge, chess, and boating. In addition, devices for use in the presentation of programs, multimedia instruction kits, and educational systems are listed by manufacturer. Cost and description are included for each device. This work, in two volumes, is the fourth edition and includes supplements through early 1971. (JK)