Lexical Similarity Between Argument and Parameter Names: An Empirical Study

Identifiers chosen by programmers convey rich semantic information that could be exploited to enhance program analysis for various software engineering tasks, e.g., anomaly detection, argument recommendation, and code completion. However, such information has not yet been fully exploited, and little is known about its properties. In this paper, we carry out an empirical study to investigate the lexical similarity between the actual argument and the formal parameter names in method invocations. By analyzing actual arguments and formal parameters from 127 Java applications and 30 open-source C applications, we observe a number of interesting and valuable findings concerning the distribution of similarity, reasons for dissimilarity, and so on. Such findings have been exploited to facilitate argument-related software engineering tasks, i.e., anomaly detection and code completion.