Schema theory proposes that knowledge is organized into structured mental frameworks — schemas — that represent our understanding of typical situations, events, and objects. Schemas guide perception (what we notice), memory (what we encode and recall), and inference (what we assume when information is missing). Introduced to cognitive psychology by Frederic Bartlett (1932) and later formalized by others, schema theory provides a powerful account of how prior knowledge shapes cognition.
Bartlett's Foundational Work
Frederic Bartlett's Remembering (1932) introduced the concept of schemas to explain systematic distortions in memory. He had English participants read an unfamiliar Native American folk tale ("The War of the Ghosts") and recall it at various intervals. Recalls showed systematic changes: details were omitted, unfamiliar elements were rationalized or replaced with more familiar ones, and the story was shortened and made more consistent with Western cultural expectations. Bartlett concluded that remembering is a reconstructive process guided by schemas.
Types of Schemas
Schemas exist at many levels. Object schemas represent knowledge about typical objects (a car has wheels, seats, and an engine). Person schemas store knowledge about social categories and individuals. Event schemas (or scripts) represent typical sequences of events (the restaurant script: enter, be seated, read menu, order, eat, pay, leave). Scene schemas represent typical spatial arrangements (kitchens contain stoves, refrigerators, and counters). Role schemas define expected behaviors for social roles (doctor, teacher, parent).
Roger Schank and Robert Abelson (1977) developed the concept of scripts — schemas for stereotypical event sequences. The "restaurant script" includes ordered actions (entering, being seated, ordering, eating, paying) with roles (customer, waiter) and props (menu, food, check). Scripts enable efficient comprehension of routine events: we understand "She left a big tip" without being told she was at a restaurant, because the restaurant script fills in the unstated context. Scripts also explain why deviations from routine are well-remembered — they violate schema-based expectations.
Effects on Memory
Schemas influence memory in multiple ways. Schema-consistent information is typically better encoded and recalled (because schemas facilitate processing). But schema-inconsistent information can also be well-remembered (because it is surprising and distinctive). Information that is neither particularly consistent nor inconsistent tends to be worst remembered. At retrieval, schemas guide reconstruction: missing details are filled in with schema-consistent defaults, sometimes producing false memories (remembering books in a professor's office that were not actually there, because the "professor's office" schema includes books).
Schema Acquisition and Change
Schemas develop through experience with repeated instances and are refined over time. Jean Piaget used the concepts of assimilation (fitting new information into existing schemas) and accommodation (modifying schemas to fit new information) to describe schema development. Once established, schemas tend to be self-perpetuating: they guide attention toward schema-consistent information, creating a confirmation bias that maintains the schema even in the face of contradictory evidence.
Modern Applications
Schema theory has been applied to reading comprehension (understanding text requires activating appropriate schemas), stereotyping (social schemas about groups guide perception and memory for group members), expert-novice differences (experts have richer, more organized domain schemas), and education (new learning must be connected to existing schemas). Cognitive load theory draws on schema concepts, proposing that well-developed schemas reduce cognitive load by allowing complex information to be processed as single units.