Effective research application has always been an important but illusive goal in environment- behavior research. However, the fact that we have not been entirely successful in realizing this goal should not be a source of particular surprise or dismay. Problems of effective research utilization are not at all unique to environment-behavior studies; they are common across disciplines and professions that endeavor to link knowledge and action (Weisman, 1983). Such difficulties are a reflection of fundamentally different ideas of what constitutes effective research application. Assessment of the applicability of the models of psychological processes presented by Böök, Küller, and S. Kaplan (this volume), therefore, is not a simple or entirely straightforward task. It is necessary to first consider the quite different yet useful ways in which application has been defined. After this discussion of application, each of the models in this section will be briefly reviewed, and some conclusions drawn regarding their applicability to environmental planning and design. Throughout this chapter, particular emphasis is placed on the need to confront the physical environment in theoretically meaningful terms and the ways in which this can advance our ability to link environmental knowledge and action. Application may be viewed in many different ways. For some practitioners, research utilization is defined in terms of “instrumental application” (Weiss, 1980). This straightforward view focuses on “the direct application of a research finding in a project, program, policy or administrative decision” (Seidel, 1985, p. 50). Such instrumental application, however, is not the only nor necessarily the most significant avenue for research application. Almost 30 years ago, in a particularly thoughtful article, policy analyst Max Millikan explored the relationship of knowledge and action. Decision makers, Millikan suggested, “commit their elementary error in an inductive fallacy—the assumption that the solution of any problem will be advanced by the simple collection of fact.” “This is easiest to observe,” Millikan noted, “in government circles, where research is considered as identical with ‘intelligence’” (1959, p. 163).