Using Tracing and Sketching to Solve Programming Problems: Replicating and Extending an Analysis of What Students Draw

Abstract

Sketching out a code trace is a cognitive assistance for programmers, student and professional. Previous research (Lister et al. 2004) showed that students who sketch a trace on paper had greater success on code 'reading' problems involving loops, arrays, and conditionals. We replicated this finding, and developed further categories of student sketching strategies. Our results support previous findings that students who don't sketch on code reading problems have a lower success rate than students who do sketch. We found that students who sketch incomplete traces also have a low success rate, similar to students who don't sketch at all. We categorized sketching strategies on new problem types (code writing, code ordering, and code fixing) and find that different types of sketching are used on these problems, not always with increased success. We ground our results in a theory of sketching as a method for distributing cognition and as a demonstration of the process of the notional machine.