A user activity-based measurement study characterizing and classifying Stack Exchange communities across multiple domains

Abstract

In recent times, Question-Answer communities have engaged much user attention and have become a major platform for knowledge sharing and discussion. Stack Exchange (SE) is one such successful community which is a collection of various domain-specific forums, each acting as an independent community in itself. In this paper, we undertake a comparative measurement study across a large number of these domain-specific forums within Stack Exchange. We analyse a number of user activity-based features of each forum and try to cluster different forums based on their similarities on this feature set. For our study, we model Stack Exchange as an Across "Forum Graph" based on inter-forum similarity, and its individual forums as: (a) A user-to-user graph (question asker-answerer) (b) A bipartite graph between questions and answerers, and (c) A bipartite graph between questions and answers. Through these graphs we present a measurement study of Stack Exchange which focuses on the similarities and differences between various forums based on the patterns of user activity on them. The clusters obtained give a high level idea of similar forums based on common users and content. We observe that communities can be classified as "discussion-based" and "fact-based" and further we classify forums on the basis of question answering patterns.