The determiners model: a cognitive model of macro development and U-shaped learning in a micro domain.

In this paper we present a cognitive model that simulates children's acquisition of the functions of determiners. Karmiloff-Smith (1979a) shows in an experiment that the performance-curve on the indefinite article through the years has an U-shape. She uses the representational redescription (RR) theory to explain this (KarmiloffSmith, 1992). We have taken this theory as a starting point for our ACT-R model. The RR theory describes cognitive development as a process in which knowledge becomes more and more explicit. Our model adds two things to the RR-theory: it explicates what the exact representations are at each representational level and it specifies the exact transition mechanisms. We have used the model to develop a more general scheme for designing developmental cognitive models.