Behavioral Path Analysis is both a theory and a methodology for studying person-environment interactions. It is designed to be applicable to the evaluation of both environments in use and proposed designed environments. This paper presents the basics of the theory, and some examples of recent applications that have guided its development. The theory relies on a control system model, and views performers in environments as being either constrained or facilitated in carrying out their purposeful activities by environmental elements that either prohibit or promote control of relevant sensed conditions. Part of this theory has been operationalized as design exercises conducted with some alternative school teachers and administrators who desired to analyze their school setting. Some preliminary results of these exercises are presented, and the analysis is briefly compared with some concepts other investigators have used in similar work. (Author)