An Interactive Computer-Based Tutor for LISP

‘This paper describes an intelligent computer-based tutor for LISP tha? incorporates some of the Ingredients of good private tutoring. The tutor consists of a problem-solver that generates steps toward a solution and an advisor that compares the problem-solver’s steps to the student’s steps. Our system can interact with students in a number of different problem spaces for algorithm design and coding. The tutor reduces memory demands by displaying relevant contextual information and directs problemsolving by immediately intervening when a student generates an unacceptable partial answer. Initial experiments indicate that our tutor is approximately twice as effective as classroom instruction. Our tutor works through the problems with the student interactively. It consists of a problem-solver and an advisor. We first describe how the problem-solver helps to interactively model students as they learn to program. We then describe the advisor and its tutoring strategy. Finally. we discuss three features of the tutor which we feel contribute to its effectiveness: 1. Use of different problem spaces to cover a broad range of programming behavior 2. Use of the graphic reminders to reduce the amount of information that a student must remember while programming