Proceedings of the Annual Meeting of the Cognitive Science Society

This is a symposium organized in memory of Allen Newell. Allen's central focus throughout his long and productive research career was the nature of the mind. The approach he pioneered in this study was the development of Unified Theories of Cognition. A unified theory of cognition (UTC) is a single set of interacting mechanisms that jointly support the full breadth and richness of uman cognition. Though no theories have yet come close to full breadth or richness, significant progress is being made along a number of fronts. Continuing to strive to reduce the remaining difference is one of the most exciting and crucial challenges facing cognitive science today. During the last decade of Allen's career, his efforts focused on the development of a particular candidate unified theory, Soar. At the Twelfth Cognitive Science Conference in 1990, we presented, in symposium form, an update on the status of Soar as a UTC. We could think of no more appropriate way to remember Allen, and his lifelong committment to his science, than to use the present opportinity to provide a second update on this topic. The presentations here were selected to illustrate some of the breadth and depth of the development of Soar as a UTC. The first presentation simply provides a general overview of Soar and its use as a UTC [Rosenblooim]. The subsequent presentations focus on three particular research efforts: visual attention[Wiesmeyer], sentence comprehension [Lewis], and learning from instruction [Huffman],These efforts share a significant recent trend in the development of Soar by focusing on its interaction with the external environment. Among the three, they span behavior in a range of time scales for human cognition (from milliseconds [Wiesmeyer], to seconds [Lewis], to minutes [Huffman]), and more general qualitative properties of human behavior