An empirical analysis of a network of expertise

• Published in: Proceedings of the 2013 IEEE/ACM International Conference on Advances in Social Networks Analysis and Mining : ASONAM 2013 : Niagara Falls, Canada, August 25-28, 2013 pp. 1387 - 1394
• Main Authors: Truc Viet Le, Minh Thap Nguyen
• Format: Conference Proceeding
• Language: English
• Published: ACM and IEEE 01.08.2013
• Subjects: Communities; Conferences; Correlation; Educational institutions; Principal component analysis; Social network services
• DOI: 10.1109/ASONAM.2013.6785882

In this paper, we analyze the network of expertise constructed from the interactions of users on the online question-answering (QA) community of Stack Overflow. This community was built with the intention of helping users with their programming tasks and, thus, questions are expected to be highly factual. This also indicates that the answers one provides may be highly indicative of one's level of expertise on the subject matter. Therefore, our main concern is how to model and characterize the user's expertise based on the constructed network and its centrality measures. We used the user's reputation established on Stack Overflow as a direct proxy to their expertise. We further made use of linear models and principal component analysis for the purpose. We found out that the current reputation system does a decent job at representing the user's expertise and that focus matters when answering factual questions. However, our model was not able to capture the other larger half of reputation which is specifically designed to reflect a user's trustworthiness besides their expertise. Along the way, we also discovered facts that have been known in earlier studies of the other/same QA communities such as the power-law degree distribution of the network and the generalized reciprocity pattern among its users.