Identifying Opinion Leaders on Social Networks Through Milestones Definition

A key problem in social network analysis is identifying influential users within a social network. To address this problem, numerous centrality measures have been defined to automatically state rankings of the users. In this article, we define the MilestonesRank, a new measure to detect opinion leaders, an important type of influential users focused on specific topics. This measure considers two parameters that can be freely adjusted depending on the needs of the analyst, namely, the interest and the exclusivity of the users regarding some specific topic. Every topic is bounded by a list of milestones over a period of time of several weeks or even months. We compare this measure with other classic measures to find opinion leaders in a real case study using the Twitter network. Our experiments show that the new measure allows us to find relevant opinion leaders that other measures are not able to detect.