Local Variables with Compound Names and Comments as Signs of Fault-Prone Java Methods

This paper focuses on two types of artifacts—local variables and comments in a method (function). Both of them are usually used at the programer’s discretion. Thus, naming local variables and commenting code can vary among individuals, and such an individual difference may cause a dispersion in quality. This paper conducts an empirical analysis on the fault-proneness of Java methods which are collected from nine popular open source products. The results report the following three findings: (1) Methods having local variables with compound names are more likely to be faulty than the others; (2) Methods having local variables with simple and short names are unlikely to be faulty, but their positive effects tend to be decayed as their scopes get wider; (3) The presence of comments within a method body can also be useful sign of fault-prone method.