1. Department of Informatics Engineering University of Porto Porto Portugal
2. Datamanagement & Biometrics University of Twente Enschede The Netherlands
3. Department of Cognitive Science and Artificial Intelligence Tilburg University Tilburg The Netherlands
4. Department of Computer Science University College London London UK
5. Centre for Research on Play in Education, Development and Learning, Faculty of Education University of Cambridge Cambridge UK
6. Computer Science Institute of Leiden University (LIACS) University of Leiden Leiden The Netherlands