Modeling vocabularies in the architectural domain. - Katja Niemann; Martin Wolpers (ICDIM, 2008)

CAMera for PLE. - Hans-Christian Schmitz; Maren Scheffel; Martin Friedrich; Marco Jahn; Katja Niemann; Martin Wolpers (EC-TEL, 2009)

Self-monitoring for Computer Users. - Maren Scheffel; Martin Friedrich; Marco Jahn; Uwe Kirschenmann; Katja Niemann; Hans-Christian Schmitz; Martin Wolpers (GI Jahrestagung, 2009)

Metadata Representation of Real-World Objects for Architectural Education. - Martin Wolpers; Katja Niemann; Christian Prause (ICALT, 2009)

Demands of Modern PLEs and the ROLE Approach. - Uwe Kirschenmann; Maren Scheffel; Martin Friedrich; Katja Niemann; Martin Wolpers (EC-TEL, 2010)

Introducing a Social Backbone to Support Access to Digital Resources. - Martin Memmel; Martin Wolpers; Massimiliano Condotta; Katja Niemann; Rafael Schirru (EC-TEL, 2010)

Skill-Based Scouting of Open Management Content. - Katja Niemann; Uta Schwertel; Marco Kalz; Alexander Mikroyannidis; Marco Fisichella; Martin Friedrich; Michele Dicerto; Kyung-Hun Ha; Philipp Holtkamp; Ricardo Kawase (EC-TEL, 2010)

A Framework for the Domain-Independent Collection of Attention Metadata. - Maren Scheffel; Martin Friedrich; Katja Niemann; Uwe Kirschenmann; Martin Wolpers (EC-TEL, 2010)

CAM in the semantic web world. - Pedro J. Muñoz Merino; Abelardo Pardo; Carlos Delgado Kloos; Mario Muñoz Organero; Martin Wolpers; Katja Niemann; Martin Friedrich (I-SEMANTICS, 2010)

Enabling the Use of Real World Objects to Improve Learning. - Katja Niemann; Martin Wolpers (ICALT, 2010)

Usage-based Object Similarity. - Katja Niemann; Maren Scheffel; Martin Friedrich; Uwe Kirschenmann; Hans-Christian Schmitz; Martin Wolpers (J. Univers. Comput. Sci., 2010)

Usage Pattern Recognition in Student Activities. - Maren Scheffel; Katja Niemann; Abelardo Pardo; Derick Leony; Martin Friedrich; Kerstin Schmidt; Martin Wolpers; Carlos Delgado Kloos (EC-TEL, 2011)

Usage-based Clustering of Learning Objects for Recommendation. - Marc-Andre Orthmann; Martin Friedrich; Uwe Kirschenmann; Katja Niemann; Maren Scheffel; Hans-Christian Schmitz; Martin Wolpers (ICALT, 2011)

Aggregating metadata to improve access to resources. - Martin Wolpers; Martin Memmel; Katja Niemann; Joris Klerkx; Marcus Specht; Alberto Giretti; Erik Duval (IRI, 2011)

Usage contexts for object similarity: exploratory investigations. - Katja Niemann; Hans-Christian Schmitz; Maren Scheffel; Martin Wolpers (LAK, 2011)

A Novel Approach towards Skill-Based Search and Services of Open Educational Resources. - Kyung-Hun Ha; Katja Niemann; Uta Schwertel; Philipp Holtkamp; Henri Pirkkalainen; Dirk Börner; Marco Kalz; Vassilis Pitsilis; Ares Vidalis; Dimitra Pappa; Markus Bick; Jan M. Pawlowski; et al. (MTSR, 2011)

A Comparison of Usage Data Formats for Recommendations in TEL. - Katja Niemann; Maren Scheffel; Martin Wolpers (RecSysTEL@EC-TEL, 2012)

Detecting and Reflecting Learning Activities in Personal Learning Environments. - Alexander Nussbaumer; Maren Scheffel; Katja Niemann; Milos Kravcik; Dietrich Albert (ARTEL@EC-TEL, 2012)

Key Action Extraction for Learning Analytics. - Maren Scheffel; Katja Niemann; Derick Leony; Abelardo Pardo; Hans-Christian Schmitz; Martin Wolpers; Carlos Delgado Kloos (EC-TEL, 2012)

Clustering by usage: higher order co-occurrences of learning objects. - Katja Niemann; Hans-Christian Schmitz; Uwe Kirschenmann; Martin Wolpers; Anna Schmidt; Tim Krones (LAK, 2012)

Usage Context-Boosted Filtering for Recommender Systems in TEL. - Katja Niemann; Martin Wolpers (EC-TEL, 2013)

A new collaborative filtering approach for increasing the aggregate diversity of recommender systems. - Katja Niemann; Martin Wolpers (KDD, 2013)

Aggregating social and usage datasets for learning analytics: data-oriented challenges. - Katja Niemann; Martin Wolpers; Giannis Stoitsis; Georgios Chinis; Nikos Manouselis (LAK, 2013)

OpenScout: harvesting business and management learning objects from the web of data. - Ricardo Kawase; Marco Fisichella; Katja Niemann; Vassilis Pitsilis; Aristides Vidalis; Philipp Holtkamp; Bernardo Pereira Nunes (WWW (Companion Volume), 2013)

Social data interoperability in educational repositories and federations. - Enayat Rajabi; Wolfgang Greller; Katja Niemann; Kostas Kastrantas; Salvador Sánchez-Alonso (Int. J. Metadata Semant. Ontologies, 2013)

Usage-Based Clustering of Learning Resources to Improve Recommendations. - Katja Niemann; Martin Wolpers (EC-TEL, 2014)

Do Optional Activities Matter in Virtual Learning Environments? - José A. Ruipérez-Valiente; Pedro J. Muñoz Merino; Carlos Delgado Kloos; Katja Niemann; Maren Scheffel (EC-TEL, 2014)

Spiral me to the core: Getting a visual grasp on text corpora through clusters and keywords. - Maren Scheffel; Katja Niemann; Sarah León Rojas; Hendrik Drachsler; Marcus Specht (LAK Workshops, 2014)

Automatic Tagging of Learning Objects Based on Their Usage in Web Portals. - Katja Niemann (EC-TEL, 2015)

Ermittlung nutzungsbasierter Ähnlichkeiten zwischen Objekten zur Unterstützung von Empfehlungssystemen im Umgang mit selten genutzten Objekten [Discovery of usage-based item similarities to support recommender systems in dealing with rarely used items]. - Katja Niemann (Ausgezeichnete Informatikdissertationen, 2015)

Increasing the accessibility of learning objects by automatic tagging. - Katja Niemann (LAK, 2015)

Getting a Grasp on Tag Collections by Visualising Tag Clusters Based on Higher-order Co-occurrences. - Katja Niemann; Maren Scheffel; Sarah León Rojas; Martin Wolpers; Hendrik Drachsler; Marcus Specht (VISLA@LAK, 2015)

Creating Usage Context-Based Object Similarities to Boost Recommender Systems in Technology Enhanced Learning. - Katja Niemann; Martin Wolpers (IEEE Trans. Learn. Technol., 2015)

Discovery of usage based item similarities to support recommender systems in dealing with rarely used items. - Katja Niemann (2015)

Analyzing the Impact of Using Optional Activities in Self-Regulated Learning. - José A. Ruipérez-Valiente; Pedro J. Muñoz Merino; Carlos Delgado Kloos; Katja Niemann; Maren Scheffel; Martin Wolpers (IEEE Trans. Learn. Technol., 2016)

Job Recommendations: The XING Case. - Katja Niemann; Daniel Kohlsdorf; Fabian Abel (Collaborative Recommendations, 2018)