Debugging by skilled and novice programmers

Two experiments investigated expert-novice differences in debugging computer programs. Debugging was done on programs provided to the subject, and were run on a microcomputer. The programs were in LOGO in Exp. 1 and Pascal in Exp. 2. Experts debugged more quickly and accurately, largely because they generated high quality hypotheses on the basis of less study of the code than novices. Further, novices frequently added bugs to the program during the course of trying to find the original one. At least for these simple programs, experts superior debugging performance seemed to be due primarily to their superior ability to comprehend the program.