Review: Analysis of Topological Characteristics of Huge Online Social Networking Services October 4, 2007Posted by shahan in online social networks.
Tags: online social networks
Analysis of Topological Characteristics of Huge Online Social Networking Services, Y-Y Ahn, S. Han, H. Kwak, S. Moon, and H. Jeong. World Wide Web 2007 (WWW ’07).
The authors present the main characteristics and evolution of online social networks while providing supporting research on how representative a sample is. Complete data from Cyworld is compared and contrasted with samples from MySpace and Orkut to show that while certain properties are similar to that of offline social networks, interesting properties are revealed which are unique to online social networks.
One of the most important concerns in selecting a sample is validating how closely it represents the complete network. In the case of Orkut, the authors found a power law exponent of 3.7; however, this contradicts the exponent of 1.5 found by Mislove et al. Furthermore, each paper has differing references for the effect of snowball sampling on the power-law exponent; Mislove et al state “collecting samples via the snowball method has been shown to underestimate the power-law coefficient ” while conversely Ahn et al state “It is known that the power-law nature in the degree distribution is well conserved under snowball sampling ”. Having small sample sizes of 100,000 nodes further exacerbates this issue.
Interestingly, the historical analysis reveals the multi-scaled degree-distribution emerging in mid 2004. While the authors were unable to accurately indicate the reason for this, an Aug 2005 report from SK Telecommunications (Cyworld’s owner) website  reveals that Mobile Cyworld was released around March 2004. Additionally, there is inconclusive proof of this using alexa.com’s pageview statistics of cyworld.com, showing a sudden drop in late 2004, possibly contributed to Mobile Cyworld. Furthermore, a previous community portal site, Freechal, began to charge for membership around the same time period, encouraging users to switch to the more interactive Cyworld, ironically, with probably higher cost due to the addictive nature of acorns .
While the data and the research methodology presented in the paper may not be completely accurate, being one of the first attempts to provide metrics for online social networks places a high value on this work.
 L. Becchetti et al, A Comparison of Sampling Techniques for Web Graph Characterization. In Proceedings of the Workshop on Link Analysis, (LinkKDD’06), Philadelphia, PA, Aug 2006.
 S. H. Lee et al, Statistical properties of sampled networks. Phys. Rev. E, 73:016102, 2006.
 http://www.sktelecom.com/eng/jsp/tlounge/presscenter/PressCenterDetail.jsp?f_reportdata_seq=3668, SKT introduces WAP version of Mobile Cyworld (accessible only through search feature on homepage).