Better Edges not Bigger Graphs: An Interaction-Driven Friendship Recommender Algorithm for Social Networks

Abstract

Online social networks have been increasingly growing over the past few years. One of the critical factors that drive these social networks’ success and growth is the friendship recommender algorithms, which are used to suggest relationships between users. Current friending algorithms are designed to recommend friendship connections that are easily accepted. Yet, most of these accepted relationships do not lead to any interactions. We refer to these relationships as weak connections. Facebook’s Friends-of-Friends (FoF) algorithm is an example of a friending algorithm that generates friendship recommendations with a high acceptance rate. However, a considerably high percentage of Facebook algorithm’s recommendations are of weak connections. The metric of measuring the accuracy of friendship recommender algorithms by acceptance rate does not correlate with the level of interactions, i.e., how much connected friends interact with one another. Consequently, new metrics and friendship recommenders are needed to form the next generation of social networks by generating better edges instead of merely growing the social graph with weak edges. This paper is a step towards this vision. We first introduce a new metric to measure the accuracy of friending recommendations by the probability that they lead to interactions. We then briefly investigate existing recommender systems and their limitations. We also highlight the consequences of recommending weak relationships within online social networks. To overcome the limitations of current friending algorithms, we present and evaluate a novel approach that generates friendship recommendations that have a higher probability of leading to interactions between users than existing friending algorithms.