“…There is a huge amount of research literature dealing with diverse aspects of the analysis of on-line social networks (OSN). Classical research efforts are devoted to identify communities within the network [ 14 , 39 , 64 ], finding influencers or key members of the virtual community [ 6 , 10 , 29 , 31 , 34 , 47 , 63 , 72 ], or describing the evolution of specific networks [ 25 , 54 , 62 ]. There is, however, very little or no work on the actual decision process conducting a user to publish some content in the OSN, e.g., posting a message in a forum of a virtual community of practice (VCoP).…”