Patricia.Mackiewicz@ISL1.RI.CMU.EDU.UUCP (04/03/87)
TOPIC: "Leaning on the World" SPEAKER: Phil Agre, MIT WHEN: Tuesday, April 7, 1987, 3:30pm WHERE: Wean Hall 5409 David Chapman and I have been studying the organization of everyday routine activity (things like making breakfast and driving to work) with an eye to understanding the human cognitive architecture. In trying to explain what we've observed, we've been lead away from mentalistic metaphors emphasizing containment and boundary (perception, behavior, programs and processes, content-bearing datastructure-like representations) and toward metaphors emphasizing agents' interactions with their worlds. Our central distinction is between an agent's "machinery" and the "dynamics" of its activity. We have found that, for the broad range of routine activity we have studied, a very simple architecture suffices. It consists of an innate "periphery" (along the lines of Marr and Ullman) and a constructed "center". Careful analysis of the reliable patterns of interaction in the agent's world allows the center to be made out of very simple hardware, in fact combinational logic. This simplicity derives largely from a new theory of representation. Where traditional representation schemes posit objectively defined "individuals" in the world, our scheme of "indexical-functional aspects" (or "aspects" for short) parses the nearby materials according to their relationship to the agent's person (i.e., indexically) and purposes (i.e., functionally). Such a scheme generalizes its understanding without putting variables in for constants, so it does not need any hardware for matching, binding, and substitution. Chapman is almost done implementing an instance of this architecture. Pengi is a program that plays the video game Pengo. Pengi's periphery simulates a person looking at a video game monitor. Its center is a fixed combinational network derived from a specification of the salient aspects of the recurring game situations. With luck, a demo will be available. Strongly suggested reading (copies may be available): Chapman and Agre, Penti: An Implementation of a Theory of Situated Activity, submitted to AAAI-87. Chapman and Agre, Abstract Reasoning as Emergent from Concrete Activity, Workshop on Reasoning About Action, 1986. Shimon Ullman, Visual Routines, MIT AI Lab Memo 723, June 1983. ************************************************************************** If you are interested in an appointment with Phil Agre please contact Patty at extension 8818 or pah@d. **************************************************************************