1. School of Educational Sciences and Psychology, University of Eastern Finland, Joensuu, Finland
2. Institute of Gerontology at Technical University Dortmund, Research Association for Gerontology, Technical University Dortmund, Dortmund, Germany
3. Department of General Health Studies, Karl Landsteiner University, Krems an der Donau, Austria
4. Division of Human-Computer Interaction, University of Gothenburg, Gothenburg, Sweden
5. Hochschule Niederrhein, Krefeld, Germany
6. FOM University of Applied Science, Münster, Germany
7. Institute for Information Systems, University of Siegen, Siegen, Germany