Combining topological properties and strong ties for link prediction

Link prediction is an important task that estimates the probability of there being a link between two disconnected nodes. The similarity-based algorithm is a very popular method that employs the node similarities to find links. Most of these types of algorithms focus only on the contribution of common neighborhoods between two nodes. In sociological theory relationships within three degrees are the strong ties that can trigger social behaviors. Thus, strong ties can provide more connection opportunities for unconnected nodes in the networks. As critical topological properties in networks, nodes degrees and node clustering coefficients are well-suited for describing the tightness of connections between nodes. In this paper, we characterize node similarity by utilizing the strong ties of the ego network (i.e., paths within three degrees) and its close connections (node degrees and node clustering coefficients). We propose a link prediction algorithm that combines topological properties with strong ties, which we called the TPSR algorithm. This algorithm includes TPSR2, TPSR3, and the TPSR4 indices. We evaluate the performance of the proposed algorithm using the metrics of precision and the Area Under the Curve (AUC). Our experimental results show the TPSR algorithm to perform remarkably better than others.