http://www2009.eprints.org/79/ Constructing Folksonomies from User-Specified Relations on Flickr Automatic folksonomy construction from tags has attracted much attention recently. However, inferring hierarchical relations between concepts from tags has a drawback in that it is difficult to distinguish between more popular and more general concepts. Instead of tags we propose to use userspecified relations for learning folksonomy. We explore two statistical frameworks for aggregating many shallow individual hierarchies, expressed through the collection/set relations on the social photosharing site Flickr, into a common deeper folksonomy that reflects how a community organizes knowledge. Our approach addresses a number of challenges that arise while aggregating information from diverse users, namely noisy vocabulary, and variations in the granularity level of the concepts expressed. Our second contribution is a method for automatically evaluating learned folksonomy by comparing it to a reference taxonomy, e.g., the Web directory created by the Open Directory Project. Our empirical results suggest that user-specified relations are a good source of evidence for learning folksonomies. Plangprasopchok, Anon Lerman, Kristina Constructing Folksonomies from User-Specified Relations on Flickr 2009-04-06T19:10:54Z Plangprasopchok, Anon <http://www2009.eprints.org/view/author/Plangprasopchok=3AAnon=3A=3A.html> and Lerman, Kristina <http://www2009.eprints.org/view/author/Lerman=3AKristina=3A=3A.html> (2009) Constructing Folksonomies from User-Specified Relations on Flickr. In: 18th International World Wide Web Conference, April 20th-24th, 2009, Madrid, Spain. application/pdf application/vnd.ms-powerpoint