AbstractThis paper describes the CAVIS interactive video system. CAVIS is an interactive teaching system that mixes videocassette pictures, text and videotex diagrams and presents these via a single television screen with sound. The student uses a keypad to respond to questions asked via the screen or narrative and, interactively, CAVIS adapts its presentation according to the responses given. Existing learning materials on VHS videocassette can be made interactive by CAVIS and have text and branching video segments integrated with their presentation. Material which has been originated on film, slide and video can be transferred on to the system. Information processing techniques are provided for the teacher to enable the authoring of text and diagrams and the mixing of text, diagrams, videocassette pictures and sound. Student performance and the effectiveness of the teaching materials used are automatically monitored and can be displayed graphically using the colour videotex display. CAVIS was designed to meet certain training needs within BP International. These are discussed along with research relating to its development.