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Dipl.-Math. Stephan Doerfel

  • Universität Kassel, Fachgebiet Wissensverarbeitung
  • Wilhelmshöher Allee 73
  • 34121 Kassel ( Germany)
  • Raum 0445F
  • Telefon: +49 (0)561 804-6252
  • Fax: +49 (0)561 804-6259
  • Email:

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Stephan Doerfel

about me

My research at Kassel University includes the investigation of scientometrics and webometrics, correlations thereof and their possible applications for recommendations and rankings. Further interests include formal concept analysis, social network analysis, and machine learning in general.
I am also a senior developer of the blue social bookmark and publication sharing system BibSonomy.


Full list of my publications and posters.

top publications

  1. Zoller, D., Doerfel, S., Jäschke, R., Stumme, G., Hotho, A.: Posted, visited, exported: Altmetrics in the social tagging system BibSonomy. Journal of Informetrics . 10, 732 - 749 (2016).
  2. Doerfel, S., Jäschke, R., Stumme, G.: The Role of Cores in Recommender Benchmarking for Social Bookmarking Systems. ACM Transactions on Intelligent Systems and Technology. 7, 40:1-40:33 (2016).
  3. Doerfel, S., Zoller, D., Singer, P., Niebler, T., Hotho, A., Strohmaier, M.: What Users Actually do in a Social Tagging System: A Study of User Behavior in BibSonomy. ACM Transactions on the Web. 10, 14:1--14:32 (2016).
  4. Doerfel, S., Zoller, D., Singer, P., Niebler, T., Hotho, A., Strohmaier, M.: How Social is Social Tagging? Proceedings of the Companion Publication of the 23rd International Conference on World Wide Web Companion. pp. 251-252. International World Wide Web Conferences Steering Committee, Seoul, Korea (2014).
  5. Doerfel, S., Hotho, A., Kartal-Aydemir, A., Roßnagel, A., Stumme, G.: Informationelle Selbstbestimmung Im Web 2.0 - Chancen Und Risiken Sozialer Verschlagwortungssysteme. Vieweg + Teubner Verlag (2013).


These are the projects I have mainly worked on. Through my research, I have further been involved with the projects Venus, EveryAware, and PoSTs .
  • PUMA

    In the DFG funded project "Akademisches Publikationsmanagement" (PUMA), we used and extended the BibSonomy software to create a new web portal that is run locally at an institution (library, university, etc.) and that integrates there with the existing eco system by connecting to the local open access repository, the publication discovery service or the eLearning platform.
  • Info 2.0

    In the DFG funded Project "Informationelle Selbstbestimmung im Web 2.0" (Info 2.0), we analyzed opportunities and risks in Web 2.0 systems, regarding issues of privacy. A second aspect that was investigated were consequences of user-generated ratings and reviews of products and particularly of scholarly publications. The project's results have been published as a book.
  • BibSonomy

    BibSonomy is a scholarly social bookmarking system where researchers manage their collections of publications and web pages. BibSonomy is an open source project, continously developed by researchers in Kassel, Würzburg, and Hanover. Functioning as a test bed for recommendation and ranking algorithms, as well as through the publicly available datasets, containing traces of user behavior on the Web, BibSonomy has been the subject of various scientific studies.


Full list of my reviewing and teaching activities.

recent activities

  • Journal Reviewer: Information Processing & Management (Elsevier) (2017)
  • PC Member: 14th International Conference on Formal Concept Analysis (ICFCA 2017), June 12 - 16, 2017, Rennes, France.
  • Journal Reviewer: Knowledge-Based Systems (Elsevier) (2017)
  • PC Member: Workshop on Knowledge Discovery, Data Mining and Machine Learning (KDML 2016) , September 12 - 14, 2016, Potsdam, Germany.
  • PC Member: European Conference on Machine Learning and Principles and Practice of Knowledge Discovery in Databases (ECML/PKDD 2016) , September 19 - 23, 2016, Riva del Garda, Italy.
  • Subreviewer: 25th International Joint Conference on Artificial Intelligence (IJCAI 2016) , July 9 - 15, 2016, New York City, USA.
  • PC Member: 2nd International Workshop on Machine learning, Optimization and Big Data (MOD 2016) , August 26 - 29, 2016, Volterra, Italy.
  • PC Member: 13th International Conference on Concept Lattices and their Applications (CLA 2016) , July 11 - 15, 2016, Moscow, Russia.
  • PC Member: 7th International Workshop on Modeling Social Media (MSM 2016) - Behavioral Analytics in Social Media, Big Data and the Web, May 12th, 2016, Montreal, Canada.
  • Journal Reviewer: IEEE Transactions on Services Computing (2015, 2016)


Sommersemester 2015

Information on previous courses can be found here at BibSonomy . In each term we offer several student projects in the context of the web 2.0 and of knowledge discovery.