Gray & Anderson, 1987

Gray, W. D., & Anderson, J. R. (1987). Change-Episodes in Coding: When and How Do Programmers Change Their Code? In G. M. Olson, S. Sheppard, & E. Soloway (Eds.), Empirical Studies of Programmers: Second Workshop, (pp. 185-197). Norwood, NJ: Ablex.

Change-Episodes in Coding: When and How Do Programmers Change Their Code?

Any change in a programmer's code or intentions while coding constitutes a change-episode. Change-episodes include error detection and correction (including false positives) as well as stylistic, and tactical changes. In this study we examine change-episodes to determine what they can add to the study of the cognition of programming. We argue that change-episodes occur most often for constructs that allow the most variability (with variability defined by the language, the task, and the programmer's history). We predict and find that those constructs that are involved in the most change-episodes are those for which much planning is needed during coding. Similarly, we discuss two ways in which a goal can be changed in a change-episode. One involves relatively minor editing of a goal's subgoals, suggesting that much planning is local to the current goal. The other entails major transformations in the goal's structure. Finally, we find that change-episodes are initiated in one of three very distinct circumstances: as an interrupt to coding, a tag-along to another change-episode, or a byproduct of symbolic execution. Our findings support the distinction between inherent and planning subgoals (2,3) and the distinction between progressive and evaluative problem-solving activities (6).