TY - JOUR N2 - In the last few years we have witnessed the emergence, primarily in online communities, of new types of social networks that require for their representation more complex graph structures than have been employed in the past. One example is the folksonomy, a tripartite structure of users, resources, and tags?labels collaboratively applied by the users to the resources in order to impart meaningful structure on an otherwise undifferentiated database. Here we propose a mathematical model of such tripartite structures that represents them as random hypergraphs. We show that it is possible to calculate many properties of this model exactly in the limit of large network size and we compare the results against observations of a real folksonomy, that of the online photography website Flickr. We show that in some cases the model matches the properties of the observed network well, while in others there are significant differences, which we find to be attributable to the practice of multiple tagging, i.e., the application by a single user of many tags to one resource or one tag to many resources TI - Random hypergraphs and their applications ID - eprints1085 SN - 1539-3755 AV - public N1 - © 2009 American Physical Society KW - PACS: 89.75.Fb KW - 89.75.Hc KW - 89.20.Hh KW - 05.65.+b IS - 6 VL - 79 PB - American Physical Society Y1 - 2009/06// UR - http://dx.doi.org/10.1103/PhysRevE.79.066118 JF - Physical Review E A1 - Ghoshal, Gourab A1 - Zlatic, Vinko A1 - Caldarelli, Guido A1 - Newman, M.E.J. ER -