CONF Negoescu_ACMMM09_2009/IDIAP Flickr Hypergroups Negoescu, Radu-Andrei Adams, Brett Phung, Dinh Venkatesh, Svetha Gatica-Perez, Daniel Flickr groups LDA EXTERNAL http://publications.idiap.ch/attachments/papers/2010/Negoescu_ACMMM09_2009.pdf PUBLIC Proceedings of the 17th ACM International Conference on Multimedia 2009 October 2009 The amount of multimedia content available online constantly increases, and this leads to problems for users who search for content or similar communities. Users in Flickr often self-organize in user communities through Flickr Groups. These groups are particularly interesting as they are a natural instantiation of the content~+~relations social media paradigm. We propose a novel approach to group searching through hypergroup discovery. Starting from roughly 11,000 Flickr groups' content and membership information, we create three different bag-of-word representations for groups, on which we learn probabilistic topic models. Finally, we cast the hypergroup discovery as a clustering problem that is solved via probabilistic affinity propagation. We show that hypergroups so found are generally consistent and can be described through topic-based and similarity-based measures. Our proposed solution could be relatively easy implemented as an application to enrich Flickr's traditional group search.