Diversified ranking on graphs from the influence maximization viewpoint

To characterize the relationship between items, graph-based ranking algorithms are widely used in various applications, such as information retrieval, recommender system, and natural language processing. Many ranking approaches tackle the dilemma between relevance and diversity. Diversity is considered as a critical objective of reducing redundancy and retrieving prestige information that has high coverage. However, the traditional evaluation of diversification is found to be deficient. In this paper, we address the coverage problem from a viewpoint of influence diffusion. Firstly, we transform the coverage problem into the diffusion problem and propose a novel measure called essential influence that combines relevance and diversity into a single function. Next, we propose a reinforced random walk, InfRank, of which the heuristic function is based on the essential influence. We applied InfRank on two applications, ranking in networks and tag recommendation. Our approach outperforms existing network-based ranking methods.