DEBUGGY

Category: Mathematics Grade Level: Grade 3 to 12

1. What is the purpose of the DEBUGGY  The computer plays the part of a "buggy program? student." The purpose of the DEBUGGY program is to diagnose students' procedural errors involving  The teacher/student gives the computer place -value in subtraction, based on their problems to solve. item responses. A faulty procedure is defined as a "bug." Examples of common bugs  The teacher/student must use clues from include: the “buggy students'” errors to find the 1. Smaller-from-Larger: Instead of bug. borrowing, the student takes the top digit, which is smaller, from the bottom one, which 5. In what types of settings is the is larger. DEBUGGY program useful? 2. Borrow-From-Zero. When borrowing from The DEBUGGY program can be used zero, the student changes the zero to nine, but independently by students and teachers both doesn't go on to borrow from the next digit to in a regular classroom and in a special the left. education class. 3. Diff-O-N=N: When the top digit is zero, the student writes down the bottom digit as 6. To what extent has research shown the the column answer. DEBUGGY program to be useful? Research has shown DEBUGGY to be a 2. With whom can it be used? useful program in several ways: This program can be used by teachers, students and remedial supports as both a  It is a highly accurate diagnostic tool for diagnostic tool and an instructional support. identifying the precise nature of students' errors in place-value subtraction. 3. What is the format of the DEBUGGY program?  It helps teachers to give students informed DEBUGGY is in the format of a computer feedback about errors and warn students game. It was created by John Seeley Brown, about where bugs may arise. Richard Burton and Kurt Van Lehn. Information about obtaining the game can be  Students learn that their mathematical obtained from the authors. difficulties are due to specific misunderstandings, rather than lack of 4. What teaching procedures should be general mathematical ability. used with the DEBUGGY program? In this program the computer implements the References teaching procedures. The general procedures 1. Bruer, J. (1997). Schools for thought: A are the following: science of learning in the classroom. Cambridge: MIT Press. 2. Brown, R. & Van Lehn, K. (1982). Towards a generative theory of "bugs". In T.P. Carpenter, J. M. Moser & T.A. Romberg (Eds.), Addition and Subtraction: A cognitive perspective. (pp. 117-13 5). Hillsdale, NJ: Erlbaum. 3. Burton, R.B. (1981). DEBUGGY: Diagnosis of errors in basic mathematical skills. In D. Sherman & J.S. Brown (Eds.), Intelligent tutoring systems. London: Academic Press. 4. Lane, S. (1989). Implications of Cognitive Psychology for Measurement and Testing: Diagnosis of Procedural Errors. Educational Measurement: Issues and Practice, 8, 17-20.

Reviewed by: Naomi Slonin