A study examined the use of Telidon, the Canadian videotex system, as a delivery vehicle for computer-based distance education in an introductory high school mechanics course. Specifically analyzed were (1) the relative educational effectiveness of Telidon, traditional correspondence, and traditional, in-school modes of instruction; (2) the computer assisted instruction (CAI) capabilities of Telidon; (3) the ability of the Telidon Viedotex System to provide and maintain data on student use; (4) the amount of training required for program developers to use the Telidon Information Provider System to generate Telidon pages; (5) the amount of training required to use Telidon terminals; and (6) the costs of developing and delivering Telidon programs. Subjects were a Telidon group, three traditional correspondence groups, and a traditional, in-school instruction group. The groups were found to be equivalent on a mechanical knowledge pretest and a mechanical reasoning aptitude test at the beginning of the course. Data were obtained through a student posttest of mechanical knowledge, interviews, document research, and a panel of experts in computer-based learning. Results indicated that the Telidon instruction was as effective as traditional correspondence and conventional in-school instruction. Sixteen recommendations, a glossary of terms, references, the Users Manual for Mechanics 12, instruments used in the evaluation study, and examples of Telidon page content are included. (Author/LMM)