In this website you can find information about folksonomies, their strenghts and weaknesses, and Sem4Tags an approach to improve multilingual folksonomies using semantic web techniques. In addition, there is information about the developed demo software to associate tags with semantic entities.
Daniela Barbosa, who is the business development manager for Synaptica at Dow Jones Client Solutions has written a fabulous eBook explaining how to mix taxonomies built by professionals and folksonomies, which let users tag content as they see fit
A. Hotho, R. Jäschke, C. Schmitz, and G. Stumme. Proceedings of the 3rd European Semantic Web Conference, volume 4011 of LNCS, page 411-426. Budva, Montenegro, Springer, (June 2006)
J. Mueller, S. Doerfel, M. Becker, A. Hotho, and G. Stumme. Proceedings of the Fifth ACM RecSys Workshop on Recommender Systems and the Social Web co-located with the 7th ACM Conference on Recommender Systems (RecSys 2013) Hong Kong, China, October 13, 2013., 1066, CEUR-WS, (2013)
T. Niebler, M. Becker, D. Zoller, S. Doerfel, and A. Hotho. Proceedings of the 25th ACM International on Conference on Information and Knowledge Management, New York, NY, USA, ACM, (2016)forthcoming.
J. Illig, A. Hotho, R. Jäschke, and G. Stumme. Knowledge Processing and Data Analysis, volume 6581 of Lecture Notes in Computer Science, Springer Berlin / Heidelberg, 10.1007/978-3-642-22140-8_9.(2011)
A. Hotho, R. Jäschke, C. Schmitz, and G. Stumme. The Semantic Web: Research and Applications, volume 4011 of Lecture Notes in Computer Science, page 411--426. Berlin/Heidelberg, Springer, (June 2006)
R. Jäschke, A. Hotho, C. Schmitz, and G. Stumme. Proceedings of the 15th International Conference on Conceptual Structures (ICCS 2007), volume 4604 of Lecture Notes in Artificial Intelligence, page 283--295. Berlin, Heidelberg, Springer-Verlag, (July 2007)
R. Jäschke, L. Balby Marinho, A. Hotho, L. Schmidt-Thieme, and G. Stumme. Knowledge Discovery in Databases: PKDD 2007, 11th European Conference on Principles and Practice of Knowledge Discovery in Databases, volume 4702 of Lecture Notes in Computer Science, page 506-514. Berlin, Heidelberg, Springer, (2007)
A. Hotho, R. Jäschke, C. Schmitz, and G. Stumme. Proc. First International Conference on Semantics And Digital Media Technology (SAMT), volume 4306 of Lecture Notes in Computer Science, page 56-70. Heidelberg, Springer, (December 2006)
A. Hotho, R. Jäschke, C. Schmitz, and G. Stumme. Informatik 2006 - Informatik für Menschen, volume 94 of Lecture Notes in Informatics, page 305--312. Bonn, Gesellschaft für Informatik, (October 2006)