A controlled experiment for evaluating quality guidelines on the maintainability of object-oriented designs

This paper presents a controlled experiment focusing on the impact of apply ing quality design principles such as the ones provided by Goad and Yourdon on the maintainability of object-oriented designs. Results, which repeat t he findings of a previous study, strongly suggest that such design principl es have a beneficial effect on the maintainability of object-oriented desig ns. It is argued that object-oriented designs are sensitive to poor design practices because the cognitive complexity introduced becomes increasingly unmanageable. However, as our ability to generalize these results is limite d, they should be considered as preliminary, i.e., it is very likely that t hey can only be generalized to programmers with little object-oriented trai ning and programming experience. Such programmers can, however, be commonly found on maintenance projects. As well as additional research, external re plications of this study are required to confirm the results and achieve co nfidence in these findings.