The evolution of knowledge in the refactoring research field

Refactoring is certainly one of the most widespread practices used by developers to improve software quality. During the last two decades, it has been the subject of an increasing number of research studies. But how much do we know about the trends, and the appearance of new topics, in the research field of refactoring? What have researchers found about its application since the time of its first introduction? In this work we provide a preliminary analysis of the state of the art and the evolution of the research on refactoring. We attempt to represent the actual body of knowledge in this field through the analysis of its cognitive structure, leveraging science mapping methodology to focus on the most relevant concepts in this research area. We model the body of knowledge by mining bibliographic databases and by retrieving the co-occurrence of keywords. We have found that some different general themes can be recognized, but not all of them have the same role and equally catalyzed researchers' interest. In addition, we provide a preliminary analysis on the trends and directions as well as the hot topics we identified in the refactoring research field.