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Research Interests: Social Computing, Recommender Systems, Complex Networks, Web Science, Open Science, Data Mining, Machine Learning

About: Ass.-Prof. Dr. Elisabeth Lex is assistant professor at Graz University of Technology and she heads the Social Computing research area at Know-Center. Her research interests include Social Computing, Recommender Systems, Complex Networks, Open Science, Web Science, Data Mining and Machine Learning. Previously, Elisabeth has been work package leader in the FP7 IP Learning Layers, and scientific coordinator of the Marie Curie IRSES Web Information Quality Evaluation Initiative (WIQ-EI) project and currently, she is task leader in the H2020 Analytics for Everyday Learning (AFEL) project. Her group also leads a work package in the H2020 OpenUp project. Elisabeth has been member of the Expert Group on Altmetrics, which advised the European Commission, DG Research and Innovation. Elisabeth has published more than 60 scientific publications in venues such as the ACM World Wide Web Conference (WWW), ACM Conference on Hypertext and Social Media (HT), ACM Conference on Recommender Systems, ACM Web Science Conference (WebSci), or the ACM/IEEE International Conference on Advances in Social Network Analysis and Mining (ASONAM) on topics like Recommender Systems, Social Network Analysis, Data Mining, and Machine Learning and she has given several invited talks in the mentioned fields. Elisabeth regularly acts as PC member and co-organizes and co-chairs a number of workshops and conferences at venues such as ACM Web Science or OpenSym. Among other courses at Graz University of Technology, Elisabeth teaches Web Science and Science 2.0/Open Science.

Grants, Fellowships and Awards:

  • 10/2015 Demo Honorable Mention Award 15th International Conference on Knowledge Technologies and Data Driven Business (i-KNOW’15)
  • 09/2015 Special Mention Third Demo Award at the Tenth Conference on Technology Enhanced Learning (EC-TEL’15)
  • 06/2015 Outstanding Paper Award 15th International Society of Scientometrics and Informetrics Conference (ISSI’15)
  • 12/2012 Industrial Research Prize (Universitätsforschungspreis der Industrie 2012), 2. Place
  • 10/2011-01/2012 Marie Curie IRSES fellowship (visiting researcher at UNSL Argentina)
  • 09/2010 Runner Up at ECML/PKDD Discovery Challenge 2010
  • 05/2010 SIGWEB Student Travel Award for Hypertext 2010
  • 2009 Scholarship: Career Program for female Scientists, Karl-Franzens-Universität Graz, Austria

Selected Publications (see full list under Publications):

  • Kowald, D., Pujari, S., Lex, E. Temporal Effects on Hashtag Reuse in Twitter: A Cognitive-Inspired Hashtag Recommendation Approach. In Proceedings of the 26th International World Wide Web Conference (WWW’2017). ACM.
  • Kopeinik, S., Kowald, D., Hasani-Mavriqi, I., Lex, E. (2017) Improving Collaborative Filtering Using a Cognitive Model of Human Category Learning. In The Journal of Web Science, Vol. 2, No. 1
  • Hasani-Mavriqi, I., Geigl, F., Pujari, S.C., Lex, E., Helic, D. The influence of social status and network structure on consensus building in collaboration networks. In Social Network Analysis and Mining 6 (1), 80 (SNAM). 2016. doi:10.1007/s13278-016-0389-y
  • Kowald, D., Lex, E. The Influence of Frequency, Recency and Semantic Context on the Reuse of Tags in Social Tagging Systems. In Proceedings of the 27th ACM Conference on Hypertext and Hypermedia (HT2016)
  • Lacic, E., Kowald, D., Lex, E. High Enough? Explaining and Predicting Traveler Satisfaction Using Airline Reviews. In Proceedings of the 27th ACM Conference on Hypertext and Hypermedia (HT2016)
  • Peters, I., Kraker, P., Lex, E., Gumpenberger, C., and Gorraiz, J. Research data explored: an extended analysis of citations and altmetrics. Scientometrics, 2016.  http://dx.doi.org/10.1007/s11192-016-1887-4
  • Kowald, D. and Lex, E. Evaluating Tag Recommender Algorithms in Real-World Folksonomies: A Comparative Study. In Proceedings of the 9th ACM Recommender Systems Conference (RecSys 2015)
  • Hasani-Mavriqi, I., Geigl, F., Pujari, S., Lex, E., Helic, D. (2015) Influence of Status on Consensus Building in Collaboration Networks. In Proceedings of the IEEE/ACM International Conference on Advances in Social Networks Analysis and Mining (ASONAM 2015)
  • Seitlinger, P., Kowald, D., Kopeinik, S., Hasani-Mavriqi, I., Ley, T., and Lex, E. (2015) Attention Please! A Hybrid Resource Recommender Mimicking Attention-Interpretation Dynamics. In 24rd International World Wide Web Conference (WWW2015), Web-Science Track, Companion Volume, New York: ACM.
  • Peters, I., Kraker, P., Lex, E., Gumpenberger, C., and Gorraiz, J. (2015) Research Data Explored: Citations versus Altmetrics. In Proceedings of the International Society for Informetrics and Scientometrics – ISSI 2015, 2015 – Outstanding Paper Award
  • Lex, E.; Pimas, O.; Simon, J. & Pammer, V., Where am I? Using Mobile Sensor Data to Predict a User’s Semantic Place with a Random Forest Algorithm, Proceedings of 9th International Conference on Mobile and Ubiquitous Systems: Computing Networking and Services (Mobiquitous 2012), 2012.

News and Events:

  • 04/2017: My PhD student Dominik Kowald will present our work on cognitive inspired hashtag recommendation at the WWW 2017 conference in Perth, Australia
  • 03/2017: I am associate chair of the OpenSym 2017 conference – check out the CfP, it will be an exciting conference!
  • 03/2017: The final report of the expert group on Altmetrics has been published on the commission website. Check it out!
  • 03/2017 09/2016: My PhD student Simone Kopeinik successfully presented a full paper on an online study of Recommender Systems in an inquiry based learning setting at LAK 2017 in Vancouver
  • 01/2017: Our paper Temporal Effects on Hashtag Reuse in Twitter: A Cognitive-Inspired Hashtag Recommendation Approach has been accepted as full paper at WWW 2017
  • 12/2016: Ilire Hasani-Mavriqi, PhD student in my team, presented our work on semantic stability, joint work with Markus Strohmaier from GESIS at Complex Networks and Applications in Milan, Italy.
  • 10/2016: I am senior PC at ACM IUI 2017 – check out the CfP!
  • 09/2016: My PhD student Simone Kopeinik successfully presented a full paper on Recommender Systems in Learning at the EC-TEL 2016 conference in Lyon
  • 08/2016: Our article on consensus dynamics in collaboration networks has been accepted to the Social Network Analysis and Mining journal. We studied the impact of social status and network structure on the consensus building process in empirical online collaboration networks, here is a link to the Open Access publication.
  • 07/2016: My PhD students Dominik Kowald and Emanuel Lacic successfully presented 3 papers at the ACM Hypertext Conference in Halifax, Canada. Emanuel presented his PhD work in the joint UMAP/Hypertext doctoral consortium. Both were lucky to receive an ACM SIGWEB Student Travel Grant!
  • 07/2016: Our workshop proposal got accepted at the i-KNOW 2016 conference! Consider submitting a short or full paper, it’ll be a great event! See the workshop website for details: http://socialcomputing.know-center.tugraz.at/rs-bda/
  • 06/2017: I was invited to join the senior programme committee of the 22nd ACM International Conference on Intelligent User Interfaces (IUI 2017) – it’s going to be an exciting event, consider submitting a paper!
  • 06/2016: Two papers accepted at the European Conference on Technology Enhanced Learning (EC-TEL 2016), one is on Recommender Systems in Learning and the other one, Take up my Tags, reports on a social tagging field study, which we carried out in the context of the Learning Layers project.
  • 06/2016: Our expert group on Altmetrics has published a Call for Evidence, check it out: https://ec.europa.eu/research/openscience/pdf/call_for_evidence_next_generation_altmetrics.pdf
  • 05/2016: I’ll present our upcoming H2020 project OpenUP (OPENing UP new methods, indicators and tools for peer review, dissemination of research) at the Science 2.0 conference in Cologne together with my colleague Peter Kraker
  • 04/2016: We got two papers accepted at the ACM Conference on Hypertext and Hypermedia (HT2016), you can check out the preprints here and here
  • 03/2016: Prof. Wai-Tat Fu from the University of Illinois visited my lab recently
  • 02/2016: Our Open Access article on citations and altmetrics of research data has been published in in Scientometrics, see http://link.springer.com/article/10.1007%2Fs11192-016-1887-4
  • 02/2016: I’ll give a keynote at DIDACTA 2016 in Cologne with the title: Data driven business:  The Impact of (Open) Data on Education and Research.
  • 01/2016: I have been appointed by the European Commission as one of six members of the Expert Group on Altmetrics. This group has been set up by the European Commission’s Directorate General Research and Innovation to propose suggestions for alternative systems to evaluate scientific work apart from quantitative citation-based impact factor
  • 01/2016: Our H2020 GARRI proposal OpenUp (OPENing UP new methods, indicators and tools for peer review, impact measurement and dissemination of research results) got accepted as the only funded project in the call. We will come up with recommendations how to disseminate research results beyond the traditional academic outlets and we will contribute to the open peer review and altmetrics research.
  • 01/2016: I am co-chair of the Mini Track on Web 2.0 Models, Methods and Tools in Knowledge Management at the 17th European Conference on Knowledge Management - check out the call for papers and submit a 300-500 word abstract until Feb 11th, 2016!
  • 10/2015: I am program chair of the Social & Ubiquitous Context-Aware Computing Track at the 15th International Conference on Knowledge Technologies and Data-driven Business (i-KNOW 2015) conference
  • 10/2015: I am program chair of the Special Track Recommender Systems: From Algorithms to Big Data Recommendation Systems at the 15th International Conference on Knowledge Technologies and Data-driven Business (i-KNOW 2015) conference
  • 10/2015: I am program chair of the Science 2.0 & Open Science Track at the 15th International Conference on Knowledge Technologies and Data-driven Business (i-KNOW 2015) conference
  • 08/2015: We got a H2020 research grant for our project AFEL (Analytics for Everyday Learning), in which we aim to study learning activities in online learning systems. My colleague Vedran Sabol from Know-Center will work on novel visual analytics tools for learning analytics and my colleague Nina Simon will lead the dissemination and exploitation work package. My group will be responsible to look into learning graph and social learning analytics. See the project website for details: http://afel.know-center.tugraz.at
  • 09/2015: We won a Special Mention Award at EC-TEL 2015 for our demo “KnowBrain: An Online Social Knowledge Repository for Informal Workplace Learning”.
  • 09/2015: I recently gave an invited talk at the Austrian Librarian Day about the citedness of research data in Vienna. Find the slides of my presentation here.
  • 07/2015: Have a look at our recent initiative to make Open Science more prominent in Austria (in German)

Want to collaborate? Contact me! elisabeth dot lex at tugraz dot at

If you are interested in collaboration, and/or in doing a project and/or thesis (bachelor, master) with me, feel free to contact me. If your interests don’t meet the suggested topics below but are related to my research, contact me as well and we’ll try to come up with a topic for your thesis.

Open master thesis topics 

  • Implementing a Recommender System Using a Cognitive Model on the Web: The aim of this thesis is to implement a computational cognitive model that explains  behavior of users on the Web and to deploy this model for recommender systems. The model will be evaluated on well-known datasets from the research community and will be compared with other state-of-the art approaches. The algorithm should be implemented in Java or Python and there is the possibility to publish the results of the thesis in form of an academic paper together with the supervisors.
  • Implementation of Social Learning Analytics: Social learning analytics make use of data generated by learners’ online activity in order to identify behaviors and patterns within the learning environment. The goal of this thesis is to collect data about learners and their contexts from the Social Web (e.g. StackExchange, Reddit) and to analyze this data using Social Network Analysis (e.g. using graph-tool). The focus is on studying direct interactions (e.g. messaging, friending, following) and/or indirect interactions, which happen when learners leave behind activity traces such as e.g. ratings or tags.
  • Influencer Detection in Academic Graphs: The aim of this thesis is to work with the publicly available Microsoft Academic Graph dataset that includes information about academic publications and citations. The main focus is to study influential nodes of various types including authors, affiliations and venues. One concrete idea would be to identify the best research institutions based on their publications and how they are cited in research articles. The realisation of other ideas is also possible.
  • Opinion Dynamics in Social Networks: The aim of this thesis is to build on our existing work, in which we studied the impact of social status on Opinion Dynamics and consensus building in Online collaboration networks. See http://www.know-center.tugraz.at/cms/wp-content/uploads/2015/08/ASONAM_2015_Paper.pdf for details. Specifically, within this thesis, the existing analysis should be extended to other types of networks. For the thesis, our open source framework for Opinion Dynamics can be used (Python, graph-tool) and extended. In case of relevant findings, there is the possibility to publish the results of the thesis in form of an academic paper together with the supervisors of the thesis.

Supervised theses

  • Tomislav Duricic (PhD thesis ongoing since 2016, expected to finish 2019). Trust Dynamics in Social Networks (co-supervision with Univ. Prof. Stefanie Lindstaedt)
  • Ilire Hasani-Mavriqi (PhD thesis ongoing since 2015, expected to finish 2018). Influence of Status on Consensus Building in Social Networks (co-supervision with Assoc. Prof. Denis Helic)
  • Simone Kopeinik (PhD thesis ongoing since 2015, expected to finish 2017). Applying Cognitive Learner Models for Recommender Systems in Small-Scale Learning Environments (co-supervision with Univ. Prof. Stefanie Lindstaedt)
  • Emanuel Lacic (PhD thesis ongoing since 2014, expected to finish 2018). Tackling Real-World Requirements in Recommender Systems (co-supervision with Univ. Prof. Stefanie Lindstaedt)
  • Dominik Kowald (PhD thesis ongoing since 2014, expected to finish 2017). Modeling Activation Processes in Human Memory to Improve Tag Recommendations  (co-supervision with Univ. Prof. Stefanie Lindstaedt)
  • Punz, A. (2016). Detection and Analysis of Communities on Twitter (master thesis, finished)
  • Müllner, P. (2016). Werkzeuge zur Analyse von Lerngruppen anhand derer Aktivitäten in einem sozialen Netzwerk (bachelor thesis, finished)
  • Steinkellner, C. (2016). Empirical Analysis of Social Networks at a Scientific Conference (master thesis, finished)
  • Feichtner, V. (2016). Information Quality in Wikipedia (master thesis, finished)
  • Feichtner, V. (2016) Processing Large Edit Networks in Wikipedia (master project, finished)
  • Duricic, T. (2015) Real-time recommendations using trust metrics and NoSQL databases, 2015. Cooperation via Erasmus+ programme together with University of Technology Zagreb, Croatia (master thesis, finished)
  • Steinkellner, C. (2015). Empirical Analysis of Social Networks at a Scientific Conference (master project, finished)