A schema is kind of knowledge component. The term is used often in cognitive and educational psychology. Authors may not always provide a definition of the term, but the intended meaning may be inferred from use. Whether or not different users of the term have the same idea about what it means is not clear.
Some examples (the bolding of "schema" was not in the orignals):
- A explicit definition in Sweller & Cooper (1988): "In the present context, schemas are defined as mental constructs that allow patterns or configurations to be recognized as belonging to a previously learned category and which specify what moves are appropriate for that category."
- Use in context in Gick & Holyoak (1983): "Reasoning by analogy typically implies a comparison of two concepts ('analogs') at the same (usually quite concrete) level of abstraction (e.g., the heart and a water pump). However, a similar mapping process may be required to compare a specific concept to a more general schema (e.g., the hear and a water pump). Furthermore, mapping may also be involved in the induction of schemas from examples (e.g., learning the abstract sense of 'pump' by comparing hearts and water pumps)." They discuss a theoretical analysis that "may serve to clarify the concept of 'schema,' which has been widely applied in cognitive models, but also widely criticized for its vagueness." In that analysis they describe "a very general 'problem schema,' which is organized hierarchically into an initial state (goals, available resources, and constraints), a solution plan, and an actual or anticipated outcome of realizing the plan." The components of a problem schema "have a natural procedural interpretation as 'situation-action' rules (Winston, 1980)".
- Some other sources to compare uses of schema: Gentner, Loewenstein, Thompson, & Forbus (2009), Koedinger & Anderson (1990).
- Gick, M.L., & Holyoak, K.J. (1983). Schema induction and analogical transfer. Cognitive Psychology, 15, 1-38.
- Koedinger, K.R., & Anderson, J.R. (1990). Abstract planning and perceptual chunks: Elements of expertise in geometry. Cognitive Science, 14, 511-550.
- Gentner, D., Loewenstein, J., Thompson, L., & Forbus, K. D. (2009). Reviving inert knowledge: Analogical abstraction supports relational retrieval of past events. Cognitive Science, 33, 1343-1382.
- Sweller, J. & Cooper, G.A. (1985) The use of worked examples as a substitute for problem solving in learning algebra. Cognition and Instruction, 2, 59–89.