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Dr. 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

I earned my phd at the University of Kassel in 2017 for my thesis "Supporting Researchers: Analyzing the Scholarly Publication Life Cycle and Social Bookmarking Systems". My research includes the investigation of scientometrics on the web (altmetrics), recommender systems (in general and specifically for scholarly literature) and their possible applications. Further interests include formal concept analysis, social network analysis, and machine learning in general.
I was also a senior developer of the blue social bookmark and publication sharing system BibSonomy. In 2016, I joined Micromata GmbH as data scientist and big data engineer.


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


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.