Breaking the barriers to successful refactoring

Refactoring, the process of changing the structure of code without changing its behavior, can be semi-automated with the help of tools. However, many tools do a poor job of communicating errors triggered by the refactoring process. This poor communication causes programmers to refactor slowly, conservatively, and incorrectly. In this paper we demonstrate problems with current refactoring tools, characterize three new tools to assist in refactoring, and describe a user study that compares these new tools against existing tools. The results of the study show that the speed, accuracy, and user satisfaction can be significantly increased The new tools have inspired a set of usability recommendations that we hope will help build a new generation of programmer-friendly refactoring tools.