Manually locating features in industrial source code: the search actions of software nomads

Expert software engineers working on large systems often need to perform feature location when moving to work in unfamiliar areas. We hypothesise that leveraging the system-specific knowledge of these may help to improve semi-automated feature location techniques. In order to assess and understand how software nomads perform manual feature location searches, two expert professional software engineers were observed in-vivo following a think-aloud protocol while performing manual feature location on a large-scale heterogeneous system. The nomads search actions were found to be around twice as effective as those reported in previous studies. This cannot be explained by sophisticated use of tools or complex queries. We conclude that system rules and conventions are frequently used by experts when constructing feature location search terms.