The influence of theory on instructional-design models of the future is explored on the basis of the theoretical developments of today. Anticipated model changes are expected to result from disparate theoretical thinking in areas such as chaos theory, constructivism, situated learning, cognitive-learning theory, and general systems theory. Instructional-system design models (ISD) are likely to continue to be a driving force among practitioners for the next decade. The typical pattern of use for such models is linear, but support for nonlinear models is appearing. The constructivist influence is permeating much thinking on instructional design and will surely be part of the newer, expanded needs-assessment orientation. Design models of the future are likely to incorporate more formative and summative evaluation. These enhancements of the typical macrodesign model will be complemented by changes in micromodels that guide the selection and sequencing of instructional strategies. Two key issues will be the nature of learner control in design models of the future and in the transfer of training strategies. The diversity of approaches in the future offers new challenges for practitioners and researchers alike. (Contains 27 references.) (SLD)