This study of the feasibility of using existing videocassettes for interactive video included field tests with Open University summer school students. The aims of the study were to discover whether video material originally made for broadcast could be used in an interactive program which involves breaking up the intended flow of the program; whether students would find it desirable to alternate between video presentation and computer-based exercises as a way of learning or revising material; and how much choice and how much advice students would need to be able to make the best use of the medium. Field trials showed that: (1) it was not feasible to avoid breaking up the video program by allowing students to interrupt it (modifications were made to the program so that it fades to black at the end of each sequence); (2) students do not make use of the opportunity to alternate between the two media, but sometimes prefer to continue using just one medium, depending upon their current strategy; and (3) students appreciate having maximum choice over both content sequence and instructional strategy; they also prefer to be forced to make a choice, rather than to interrupt the video as they wish, and to have advice on an appropriate content sequence should they wish to make use of it. (EW)