Abstract
This paper addresses issues of the nature of expertise in programming and asks whether “programming plans” represent the underlying deep structure of a program. It reports an experiment that investigated the effect, on experienced programmers, of highlighting the plan structure of a computer program, while they were performing both plan-related and unrelated tasks. The effect was examined in both Pascal and BASIC. For Pascal programmers, perceptual cues to the plan structure were useful only for plan-related tasks, but the same cues were of no benefit to experienced BASIC programmers in any of the tasks. These results suggest that the actual content of programming plans does not generalise across different languages, although it is possible that the BASIC programmers can use other plans. From these results a more detailed description of programming plans and their role in programming expertise can be developed. The fact that BASIC programmers were not sensitive to the same plans as Pascal programmers implies that plans cannot represent the underlying deep structure of the programming problem.
