"The purpose of this symposium was to bring together some of the leading exponents of different theoretical positions on the environment-behavior interface with implications for design. Altman and Rogoff (1987) and Moore (1987) have presented two frameworks for conceptualizing theory. Earlier symposia convened at the EDRA-Atlanta, lAPS-Haifa, IAAP-Jerusalem, and EDRA-Ottawa conferences have explored the implications of these two competing frameworks. Chapters on theory have been published in Advances in Environment Behavior and Design (Vol. 1, 1987; Vol. 2, in press). This symposium built off those sessions and chapters and again provided an opportunity for some of the leading theoreticians to present their ideas and to expose them to critical commentary by colleagues and lAPS members. As stated in the Preface to Volume 1 of the Advances series, there are at least three different orientations to the field: the pragmatic, social problem orientation; a range. of empirical orientations; and various theoretical orientations. "Theories" have been called by a number of different names- -explanatory theories, design theories, theories of good form, manifestos, conceptual frameworks, models, world views, theoretical orientations, and even metaphysical blueprints. The Altman-Rogoff and Moore taxonomies have been proposed as a way of structuring this seeming morass and bringing some order to this burgeoning aspect of our field. The past symposia, and the first two volumes of the Advances series, have critically examined some of these theoretical directions including phenomenology, empiricism, structuralism, and behavioral ecology. The symposium this year focused on normative or explanatory environment-behavior theories and positive or prescriptive design theories."