@article{cattuto2007networkb, author = {Cattuto, Ciro and Schmitz, Christoph and Baldassarri, Andrea and Servedio, Vito D. P. and Loreto, Vittorio and Hotho, Andreas and Grahl, Miranda and Stumme, Gerd}, editor = {Hoche, Susanne and Nürnberger, Andreas and Flach, Jürgen}, interhash = {fc5f2df61d28bc99b7e15029da125588}, intrahash = {da6c676c5664017247c7564fc247b190}, issn = {0921-7126}, journal = {AI Communications Journal, Special Issue on ``Network Analysis in Natural Sciences and Engineering''}, number = 4, pages = {245-262}, publisher = {IOS Press}, title = {Network Properties of Folksonomies}, url = {http://www.kde.cs.uni-kassel.de/stumme/papers/2007/cattuto2007network.pdf}, vgwort = {67}, volume = 20, year = 2007 } @inproceedings{schmitz07network, address = {Banff}, author = {Schmitz, Christoph and Grahl, Miranda and Hotho, Andreas and Stumme, Gerd and Catutto, Ciro and Baldassarri, Andrea and Loreto, Vittorio and Servedio, Vito D. P.}, booktitle = {Proc. WWW2007 Workshop ``Tagging and Metadata for Social Information Organization''}, day = 8, interhash = {20bd468c1c9b71206ac6f8b67ed676d6}, intrahash = {23a0a0cd67ab0014e0346527e986caeb}, month = may, title = {Network Properties of Folksonomies}, url = {http://www.kde.cs.uni-kassel.de/stumme/papers/2007/schmitz07network.pdf}, year = 2007 } @article{cattuto2009collective, abstract = {The enormous increase of popularity and use of the worldwide web has led in the recent years to important changes in the ways people communicate. An interesting example of this fact is provided by the now very popular social annotation systems, through which users annotate resources (such as web pages or digital photographs) with keywords known as “tags.” Understanding the rich emergent structures resulting from the uncoordinated actions of users calls for an interdisciplinary effort. In particular concepts borrowed from statistical physics, such as random walks (RWs), and complex networks theory, can effectively contribute to the mathematical modeling of social annotation systems. Here, we show that the process of social annotation can be seen as a collective but uncoordinated exploration of an underlying semantic space, pictured as a graph, through a series of RWs. This modeling framework reproduces several aspects, thus far unexplained, of social annotation, among which are the peculiar growth of the size of the vocabulary used by the community and its complex network structure that represents an externalization of semantic structures grounded in cognition and that are typically hard to access.}, author = {Cattuto, Ciro and Barrat, Alain and Baldassarri, Andrea and Schehr, Gregory and Loreto, Vittorio}, doi = {10.1073/pnas.0901136106}, eprint = {http://www.pnas.org/content/106/26/10511.full.pdf+html}, interhash = {0d9b41d0509bf9ee8004010663452a22}, intrahash = {0d1491f34bcd6f29c0a59e449cfdffa1}, journal = {Proceedings of the National Academy of Sciences}, number = 26, pages = {10511-10515}, title = {Collective dynamics of social annotation}, url = {http://www.pnas.org/content/106/26/10511.abstract}, volume = 106, year = 2009 } @inproceedings{capocci2010friendship, abstract = {We study the semantic assortativity in the social networks hosted by the Flickr folksonomy, based both on the contact data and on the group membership data provided by the users. The social network built this way are complex one. Besides, one observes a clear assortativity pattern, stronger than in a suitable null model adopted for a comparison. Nevertheless, such semantical similarity does not appear to develop during the community evolution, but is rather the result of a pre-existing shared background between users.}, address = {New York, NY, USA}, author = {Capocci, Andrea and Baldassarri, Andrea and Servedio, Vito D. P. and Loreto, Vittorio}, booktitle = {MSM '10: Proceedings of the International Workshop on Modeling Social Media}, doi = {10.1145/1835980.1835988}, interhash = {ee0aa2dc8267b105f9491e04f5edcee2}, intrahash = {de0827988d3609f2ac66bd90f12ac93a}, isbn = {978-1-4503-0229-6}, location = {Toronto, Ontario, Canada}, pages = {1--4}, publisher = {ACM}, title = {Friendship, collaboration and semantics in Flickr: from social interaction to semantic similarity}, url = {http://portal.acm.org/citation.cfm?id=1835980.1835988}, year = 2010 } @article{cattuto2007networkb, author = {Cattuto, Ciro and Schmitz, Christoph and Baldassarri, Andrea and Servedio, Vito D. P. and Loreto, Vittorio and Hotho, Andreas and Grahl, Miranda and Stumme, Gerd}, editor = {Hoche, Susanne and Nürnberger, Andreas and Flach, Jürgen}, interhash = {fc5f2df61d28bc99b7e15029da125588}, intrahash = {da6c676c5664017247c7564fc247b190}, issn = {0921-7126}, journal = {AI Communications Journal, Special Issue on ``Network Analysis in Natural Sciences and Engineering''}, number = 4, pages = {245-262}, publisher = {IOS Press}, title = {Network Properties of Folksonomies}, url = {http://www.kde.cs.uni-kassel.de/stumme/papers/2007/cattuto2007network.pdf}, vgwort = {67}, volume = 20, year = 2007 } @inproceedings{cattuto2007emergent, address = {Dresden, Germany}, author = {Cattuto, Ciro and Baldassarri, Andrea and Servedio, Vito D. P. and Loreto, Vittorio}, booktitle = {Proceedings of the European Confeence on Complex Systems}, interhash = {9afde66e2d53e2f23bed303f7bda30af}, intrahash = {3977cdaf1ce7a4c500ac5cfd5a91c9e5}, month = {October}, title = {Emergent Community Structure in Social Tagging Systems}, year = 2007 } @inproceedings{cattuto2007vocabulary, abstract = { We analyze a large-scale snapshot of del.icio.us and investigate how the number of different tags in the system grows as a function of a suitably defined notion of time. We study the temporal evolution of the global vocabulary size, i.e. the number of distinct tags in the entire system, as well as the evolution of local vocabularies, that is the growth of the number of distinct tags used in the context of a given resource or user. In both cases, we find power-law behaviors with exponents smaller than one. Surprisingly, the observed growth behaviors are remarkably regular throughout the entire history of the system and across very different resources being bookmarked. Similar sub-linear laws of growth have been observed in written text, and this qualitative universality calls for an explanation and points in the direction of non-trivial cognitive processes in the complex interaction patterns characterizing collaborative tagging.}, author = {Cattuto, Ciro and Baldassarri, Andrea and Servedio, Vito D. P. and Loreto, Vittorio}, interhash = {7de017393b2d48335e209a9db23e08b6}, intrahash = {fb163dd424fa1eb40640340f27ee0ea4}, title = {Vocabulary growth in collaborative tagging systems}, url = {http://www.citebase.org/abstract?id=oai:arXiv.org:0704.3316}, year = 2007 } @article{cattuto2007network, abstract = {Social resource sharing systems like YouTube and del.icio.us have acquired a large number of users within the last few years. They provide rich resources for data analysis, information retrieval, and knowledge discovery applications. A first step towards this end is to gain better insights into content and structure of these systems. In this paper, we will analyse the main network characteristics of two of these systems. We consider their underlying data structures - so-called folksonomies - as tri-partite hypergraphs, and adapt classical network measures like characteristic path length and clustering coefficient to them.Subsequently, we introduce a network of tag co-occurrence and investigate some of its statistical properties, focusing on correlations in node connectivity and pointing out features that reflect emergent semantics within the folksonomy. We show that simple statistical indicators unambiguously spot non-social behavior such as spam.}, address = {Amsterdam, The Netherlands}, author = {Cattuto, Ciro and Schmitz, Christoph and Baldassarri, Andrea and Servedio, Vito D. P. and Loreto, Vittorio and Hotho, Andreas and Grahl, Miranda and Stumme, Gerd}, file = {cattuto2007network.pdf:cattuto2007network.pdf:PDF}, groups = {public}, interhash = {fc5f2df61d28bc99b7e15029da125588}, intrahash = {1dfe8b2aa29adf4929cbb845950f78bc}, issn = {0921-7126}, journal = {AI Communications}, journalpub = {1}, month = dec, number = 4, pages = {245--262}, publisher = {IOS Press}, timestamp = {2010-11-10 15:35:25}, title = {Network properties of folksonomies}, url = {http://portal.acm.org/citation.cfm?id=1365538}, username = {dbenz}, volume = 20, year = 2007 } @article{cattuto2007network, abstract = {Social resource sharing systems like YouTube and del.icio.us have acquired a large number of users within the last few years. They provide rich resources for data analysis, information retrieval, and knowledge discovery applications. A first step towards this end is to gain better insights into content and structure of these systems. In this paper, we will analyse the main network characteristics of two of these systems. We consider their underlying data structures - so-called folksonomies - as tri-partite hypergraphs, and adapt classical network measures like characteristic path length and clustering coefficient to them. Subsequently, we introduce a network of tag co-occurrence and investigate some of its statistical properties, focusing on correlations in node connectivity and pointing out features that reflect emergent semantics within the folksonomy. We show that simple statistical indicators unambiguously spot non-social behavior such as spam. }, address = {Amsterdam, The Netherlands}, author = {Cattuto, Ciro and Schmitz, Christoph and Baldassarri, Andrea and Servedio, Vito D. P. and Loreto, Vittorio and Hotho, Andreas and Grahl, Miranda and Stumme, Gerd}, interhash = {fc5f2df61d28bc99b7e15029da125588}, intrahash = {f15cc7613101babb2c3ed1927e35213a}, issn = {0921-7126}, journal = {AI Communications}, month = dec, number = 4, pages = {245--262}, publisher = {IOS Press}, title = {Network Properties of Folksonomies}, url = {http://www.kde.cs.uni-kassel.de/pub/pdf/cattuto2007network.pdf}, volume = 20, year = 2007 } @inproceedings{schmitz07network, address = {Banff}, author = {Schmitz, Christoph and Grahl, Miranda and Hotho, Andreas and Stumme, Gerd and Catutto, Ciro and Baldassarri, Andrea and Loreto, Vittorio and Servedio, Vito D. P.}, booktitle = {Proc. WWW2007 Workshop ``Tagging and Metadata for Social Information Organization''}, day = 8, interhash = {20bd468c1c9b71206ac6f8b67ed676d6}, intrahash = {23a0a0cd67ab0014e0346527e986caeb}, month = may, title = {Network Properties of Folksonomies}, url = {http://www.kde.cs.uni-kassel.de/stumme/papers/2007/schmitz07network.pdf}, year = 2007 }