World Wide Web (2012) 15:213–232 DOI 10.1007/s11280-011-0143-3 A study of homophily on social media Halil Bisgin · Nitin Agarwal · Xiaowei Xu Received: 4 September 2010 / Revised: 26 July 2011 / Accepted: 4 August 2011 / Published online: 19 August 2011 © Springer Science+Business Media, LLC 2011 Abstract The fact that similarity breeds connections, the principle of homophily, has been well-studied in existing sociology literature. Several studies have observed this phenomenon by conducting surveys on human subjects. These studies have concluded that new ties are formed between similar individuals. This phenomenon has been used to explain several socio-psychological concepts such as, segregation, community development, social mobility, etc. However, due to the nature of these studies and limitations because of involvement of human subjects, conclusions from these studies are not easily extensible in online social media. Social media, which is becoming the infinite space for interactions, has exceeded all the expectations in terms of growth, for reasons beyond human mind. New ties are formed in social me- dia in the same way that they emerge in real-world. However, given the differences between real world and online social media, do the same factors that govern the construction of new ties in real world also govern the construction of new ties in social media? In other words, does homophily exist in social media? In this article, we study this extremely significant question. We propose a systematic approach by studying three online social media sites, BlogCatalog, Last.fm, and LiveJournal and report our findings along with some interesting observations. The results indicate that the influence of interest-based homophily is not a very strong leading factor for constructing new ties specifically in the three social media sites with implications to strategic advertising, recommendations, and promoting applications at large. H. Bisgin Applied Science Department, University of Arkansas at Little Rock, Little Rock, AR 72204, USA e-mail: hxbisgin@ualr.edu N. Agarwal (B ) · X. Xu Information Science Department, University of Arkansas at Little Rock, Little Rock, AR 72204, USA e-mail: nxagarwal@ualr.edu X. Xu e-mail: xwxu@ualr.edu