Efficient sentiment correlation for large-scale demographics

Analyzing sentiments of demographic groups is becoming important for the SocialWeb, where millions of users provide opinions on a wide variety of content. While several approaches exist for mining sentiments from product reviews or micro-blogs, little attention has been devoted to aggregating and comparing extracted sentiments for different demographic groups over time, such as ‘Students in Italy’ or ‘Teenagers in Europe’. This problem demands efficient and scalable methods for sentiment aggregation and correlation, which account for the evolution of sentiment values, sentiment bias, and other factors associated with the special characteristics of web data. We propose a scalable approach for sentiment indexing and aggregation that works on multiple time granularities and uses incrementally updateable data structures for online operation. Furthermore, we describe efficient methods for computing meaningful sentiment correlations, which exploit pruning based on demographics and use top-k correlations compression techniques. We present an extensive experimental evaluation with both synthetic and real datasets, demonstrating the effectiveness of our pruning techniques and the efficiency of our solution.