Classification of bug fix patterns with implications for software testing

No software quality assurance technique is effective against all types of faults. Therefore, developers and testers have to choose from a wide variety of possible techniques, to give the best chance of detecting those types of faults which are most likely to be present. However, there is little empirical evidence available in the open literature to support these intuitions. To support these intuitions, I have devised a fix pattern scheme of 14 types for if-conditional fixes and a fix pattern scheme of 14 types for Method Invocation related fixes. The implications of bug fix patterns and their frequencies were considered for choosing suitable software testing techniques. Furthermore, the collected data were used to support the Competent Programmer Hypothesis.