Online platforms, such as Meetup and Plancast, have recently become popular for planning gatherings and event organization. However, there is a surprising lack of studies on how to effectively and efficiently organize social events for a large group of people through such platforms. In this paper, we study the key computational problem involved in organization of social events, to our best knowledge, for the first time.

We propose the Social Event Organization (SEO) problem as one of assigning a set of events for a group of users to attend, where the users are socially connected with each other and have innate levels of interest in those events. As a first step toward Social Event Organization, we introduce a formal definition of a restricted version of the problem and show that it is NP-hard and is hard to approximate. We propose efficient heuristic algorithms that improve upon simple greedy algorithms by incorporating the notion of phantom events and by using look-ahead estimation. Using synthetic datasets and three real datasets including those from the platforms Meetup and Plancast, we experimentally demonstrate that our greedy heuristics are scalable and furthermore outperform the baseline algorithms significantly in terms of achieving superior social welfare.