Analyzing Time-Decay Effects of Mediating-Objects in Creating Trust-Links

We address the problem of modeling trust network evolution through social communications among users in a social media site. In particular, we focus on a social trust-link created between two users having mediating-objects such as mediating-users and mediating-items, and analyze the time-decay effects of mediating-objects on social trust-link creation. To this end, we first introduce the basic TCM model that can be regarded as a conventional link prediction method based on mediating-objects, and propose the TCM model with time-decay by incorporating an appropriate time-decay function into it. We present an efficient learning method of the proposed model, and apply it to an analysis of social trust-link creation in a product review site. We show that the proposed model significantly outperforms the basic TCM model in terms of prediction performance, and clarify several properties of user behavior for social trust-link creation.