This bulletin focuses on the role of computer-assisted instruction (CAI) in environmental education programs. The utility of this approach in helping students learn in the cognitive, affective, and/or psychomotor domains is examined and its effectiveness is compared to other instructional devices and methods. Major topics are organized and explained under 10 specific question headings. These are: (1) why computerized instruction?; (2) why computerized simulation?; (3) why simulate?; (4) why time-sharing?; (5) what materials became available?; (6) are energy-related CAI programs available?; (7) what are multi-user computer simulations?; (8) what are the impacts of microcomputers?; (9) have CAI materials proliferated?; and (10) what does research say? An extensive reference list is included (with ED numbers for documents in ERIC). (ML)