Instructional Audio (audiocassette, one-way or two-way teleconference, broadcast (radio, telephone, etc...))
Computer Assisted Instruction (CAI) uses the computer as a self-contained teaching machine to present discrete lessons to achieve specific but limited educational objectives. There are several CAI modes, including: drill and practice, tutorial, simulations and games, and problem-solving.
Computer Managed Instruction (CMI) uses the computer's branching, storage, and retrieval capabilities to organize instruction and track student records and progress. The instruction need not be delivered via computer, although often CAI (the instructional component) is combined with CMI.
Computer Mediated Communication (CMC) describes computer applications that facilitate communication. Examples include electronic mail, computer conferencing, and electronic bulletin boards.
Computer-Based Multimedia: HyperCard, hypermedia, and a still-developing generation of powerful, sophisticated, and flexible computing tools have gained the attention of distance educators in recent years. The goal of computer-based multimedia is to integrate various voice, video, and computer technologies into a single, easily accessible delivery system.
Print instruction (correspondence)
Videoconferencing (videolink + remote and local computer display)
Audioconferencing (audiolink + remote and local computer display)