Technical report available

[Melanie Mitchell]

The following report is available from the Center for 
Research on Concepts and Cognition at Indiana University:

   The Role of Computational Temperature in a Computer Model 
               of Concepts and Analogy-Making

           Melanie Mitchell and Douglas R. Hofstadter
         Center For Research on Concepts and Cognition
                      Indiana University

                          Abstract

In this paper we discuss the role of computational temperature
in Copycat, a computer model of the mental mechanisms underlying
human concepts and analogy-making.  Central features of Copycat's
architecture are a high degree of parallelism, fine-grained 
distributed processing, competition, randomness, and an interaction
of bottom-up perceptual pressures with an associative, overlapping,
and context-sensitive conceptual network.  In Copycat, 
computational temperature is used both to measure the amount and 
quality of perceptual organization created by the program as 
processing proceeds, and, reciprocally, to continuously control the 
degree of randomness in the system.  In this paper we will discuss 
the role of temperature in two aspects of perception central to 
Copycat's behavior:  (1) the emergence of a "parallel terraced scan", 
in which many possible courses of action are explored simultaneously, 
each at a speed and to a depth proportional to moment-to-moment 
estimates of its promise, and (2) the ability to restructure initial 
perceptions -- sometimes radically -- in order to arrive at a deeper, 
more essential understanding of a situation.  We will also compare our 
notion of temperature to similar notions in other computational 
frameworks.  Finally, an example will be given of how temperature is 
used in Copycat's creation of a subtle and insightful analogy.

For copies of this report, send a request for CRCC-89-1
to helga at cogsci.indiana.edu

or to 
Helga Keller
Center for Research on Concepts and Cognition
Indiana University
Bloomington, Indiana, 47408