This study applied previously identified cognitive theory and research to the development of an instructional design model for teaching mental aspects underlying work and family activities in a context of rapid change and high technology. The model was tested by developing a prototype, materials required by the prototype were developed, and the design was tested for effectiveness in facilitating development of the mental aspects underlying activities within the selected domain. In the development of the model, four factors were identified as particularly significant in supporting learners' knowledge construction: fidelity of the learning situation to the real world, visualization, range and depth of learners' experiences, and mediation of learners' interpretations of their experiences. Knowledge constructed by learners was intended to: (1) integrate goals, intentions, and actions with features of the external world and domain-knowledge concepts and principles; (2) focus attention on deep-level features; (3) facilitate interpretations in terms of powerful, superordinate-level concepts and principles; and (4) support sensitivity to subtle but important variations among cases. A computer-based videodisc learning environment was developed as a prototype, and its intermediate level of instruction was tested. Findings supported the effectiveness of the learning environment in elaborating, modifying, and reorganizing knowledge structures in ways that enhance capacities to detect deep-level features and to apply knowledge in making judgments regarding actions that fit a situation. (51 references) (CML)