Cognitive structures in the comprehension and memory of computer programs: an investigation of compu

Abstract : A theoretical framework, based upon recent studies in cognitive psychology on memory for text, was developed to explain certain aspects of human behavior during computer program comprehension and debugging. A central concept of this framework is that the information contained in a program is represented in a programmer's memory as a connected, partially ordered list (hierarchy) of 'propositions' (units of information with properties similar to those observed in research on text memory). An experiment was performed to test the hypothesis that the difficulty in finding a program bug is a function of the bug's location in this hierarchy. This experiment compared the effects of bug location, bug type (array, iteration, assignment) and specific program. Each of 48 subjects debugged two separate programs, with one type of bug at two different hierarchical levels in each program. A preliminary analysis suggested that all three factors -- program, bug type, and bug location -- significantly affected the time required to locate program bugs. Detailed analyses, however, suggested the program and bug type variables could be explained in terms of the bug location variable and the a bug's location in a program's underlying propositional hierarchy is a principal factor affecting performance in a comprehension and debugging task.