Experimental Analysis of the Cognitive Processes of Program Maintainers during Software Maintenance

The proposed method for determining how "maintainers" develop an understanding of programs that need to be changed is designed to reflect actual maintenance work and to be objective. Use of this method to investigate the strategies used by experts and novices to develop such an understanding showed that: (1) both novices and experts tend to study the same modules; (2) experts study other modules related to the target module much more than novices do; and (3) experts look at many more modules during a given time period than novices do. Analysis of the changes in a maintainer's strategy showed that both novices and experts start by browsing the whole program to develop an understanding of its function and structure. They then shift their attention to the target module to develop a detailed understanding of it. In the final stage, both experts and novices again browse the overall program to check their understanding.