Presents recent changes in the technology, expansion of courseware, and distribution to other institutions of the interactive videodisc courseware utilized as a significant part of the undergraduate chemistry curriculum at the University of Illinois since 1986. (JJK)

This paper argues that Merrill's instructional transaction theory provides a framework that can decrease learners' problems in using computer simulations by specifying transaction shells rather than frames in designing interactive courseware. The three types of data used in a transaction, i.e., an instructional algorithm, are identified as a…