A systematic approach to the study of environmental psychol-ogy requires a limited set of basic variables to characterize everyday environments. Traditionally, experimental psychologists have described stimulus configurations with dimensions such as hue, temperature, pitch of sound, cr loudness of sound–that is, vvith the stimulus categories used in studies of perception. However, this approach fails to yield the required parsimony for studies of environmental problems where there is a need to describe settings that include stimulation in all the Sense modalities simultaneously, as well as spatial and temporal variations within each modality. Consider the many colors, sounds, odors, temperatures, and textures in any everyday setting, especially over any length of time. The combination of all these variations results in different patterns, contrasts, and �mounts of information to be processed, which affect the

AUTHOR'S NOTE: This study was supported by US Public Health Service grant MH 13509. Appreciation is expressed to Christine Battraw for her help in carrying out Study 2. This paper includes rewritten segments from chapter 5 of our An Approach to Environmental Psychology. Copyright (1974) by The M17 Press and