A Critic for LISP

Abstract

Our goal Is to establish the conceptual foundations for using the COf'Tllutatlonal power that is or will be available on computer systems. Much of the available computing power is wasted, however, if users have difficulty understanding and using the full potential of these systems. Too much attention in the past has been given to the technology of computer systems and not enough to the effects of that technology, which has produced inadequate solutions to real-world problems, imposed unnecessary constraints on users, and failed to respond to changing needs. We have designed and implemented a critic for LISP as a prototype of an intelligent support system. Critics enhance incremental learning of a system and support learning strategies such as learning on demand. Our LISP-CRITIC has knowledge about how to if'Tllrove USP programs locally, following a style as defined by its rules. The advice given Is based on the hypothesized knowledge of the user contained in the system's model of the user. Additional tools (e.g., a knowledge browser and visualization support) are available to explain and illustrate the advice. The LISP-CRITIC has been used by intermediate and expert LISP programmers and has proven to be a valuable tool for incremental learning of LISP and for if'Tllroving programs.