The results of research on the effectiveness of four alternative instructional media are reviewed: traditional classroom instruction, instructional radio, instructional television, programed instruction, and computer-assisted instruction (CAI). It was concluded that students learn effectively from all these media; relatively few studies indicate significant differences between media in effectiveness. Future research should focus on four areas: 1) determine if programed instruction and CAI can be shown to save instructional time over a longer period and with a higher percentage of students; 2) investigate long-term effects of instructional technologies on students' motivations; 3) investigate the long-term effects of the individualization and privacy made possible by some of the technologies; and 4) future investigations should consider more imaginative uses of new technologies instead of using technology to provide a simulation of some traditional method. (RH)