The term, "schema," used largely as a descriptive convenience rather than a theoretical guidepost in social psychology is examined through an analysis of its development, function, and structure. This paper articulates a model of schema development in adults by defining a schema as a representation of some stimulus domain and a set of rules or plans for processing incoming material and drawing inferences from that material. Data and impressions regarding the four stages of schema development are presented, paralleling the developmental stages that children go through in acquiring grammar and lexical concept. Since few studies have looked beyond a linear relationship between schema processing and expertise, the issue of multiple stages is identified as an area for future research efforts. (Author/CS)