Rationale in Development Chat Messages: An Exploratory Study

Chat messages of development teams play an increasinglysignificant role in software development, having replacedemails in some cases. Chat messages contain informationabout discussed issues, considered alternatives and argumentationleading to the decisions made during software development. These elements, defined as rationale, are invaluable duringsoftware evolution for documenting and reusing developmentknowledge. Rationale is also essential for coping with changesand for effective maintenance of the software system. However, exploiting the rationale hidden in the chat messages is challengingdue to the high volume of unstructured messages covering a widerange of topics. This work presents the results of an exploratorystudy examining the frequency of rationale in chat messages, the completeness of the available rationale and the potential ofautomatic techniques for rationale extraction. For this purpose, we apply content analysis and machine learning techniques onmore than 8,700 chat messages from three software developmentprojects. Our results show that chat messages are a rich source ofrationale and that machine learning is a promising technique fordetecting rationale and identifying different rationale elements.