DAVID H. JONASSEN is professor and chair of instructional technology at the University of Colorado at Denver. He is author/editor of several books, including Instructional Designs for Microcomputer Courseware.WALLACE H. HANNUM is a member of the faculty of the School of Education at the University of North Carolina, Chapel Hill. He is the author of Developing Computer Based Instruction.MARTIN TESSMER is assistant professor of instructional design at the University of Colorado at Denver. He is the author (with David Jonassen) of A Nonprogrammer's Guide to Designing Instruction for Microcomputers.