GPOP: Scalable Group-level Popularity Prediction for Online Content in Social Networks

Predicting the popularity of online content in social networks is important in many applications, ranging from ad campaign design, web content caching and prefetching, to web-search result ranking. Earlier studies target this problem by learning models that either generalize behaviors of the entire network population or capture behaviors of each individual user. In this paper, we claim that a novel approach based on group-level popularity is necessary and more practical, given that users naturally organize themselves into clusters and that users within a cluster react to online content in a uniform manner. We develop a novel framework by first grouping users into cohesive clusters, and then adopt tensor decomposition to make predictions. In order to minimize the impact of noisy data and be more flexible in capturing changes in users' interests, our framework exploits both the network topology and interaction among users in learning a robust user clustering. The PARAFAC tensor decomposition is adapted to work with hierarchical constraint over user groups, and we show that optimizing this constrained function via gradient descent achieves faster convergence and leads to more stable solutions. Extensive experimental results over two social networks demonstrate that our framework is scalable, finds meaningful user groups, and significantly outperforms eight baseline methods in terms of prediction accuracy.