Schemas, Computation, and Language Acquisition

The word schema is used in three overlapping, but somewhat different, senses: as a translation of Piaget’s term scheme; as the unit of process-and-representation in Arbib’s theory of perceptual structures and distributed motor control; and as a computational unit in the attempt to relate the mechanisms underlying language acquisition to other cognitive systems. In the Piagetian literature, the term schema may refer either to a set of regularities in observed behavior or to an internal mechanism which could produce such regularities. A major task, then, is to relate ‘private’ mechanisms to public behavior. The first section of this paper provides a general analysis of this problem. The second offers a more concrete example: a computational model of language acquisition. The third section then relates these considerations to Piaget’s notion of mutual verification and to some general philosophical questions about learning.