It recognized that urban expansion was not haphazard but quite strongly controlled by community-level forces such as land values, zoning ordinances, landscape features, circulation corridors, and historical contingency. This was characterized as ecological because the external factors were neither chance nor intended, but rather arose from the natural forces in the environment which limit the adaptive spatial and temporal relationships between individuals. The school sought to derive patterns from a study of processes, rather than to ascribe processes to observed patterns and the patterns they saw emerge, are strongly reminiscent of Clements' ideas of community development.