1. ITI/LARSyS, Instituto Superior Técnico, University of Lisbon, Portugal
2. LASIGE, Faculdade de Ciências, Universidade de Lisboa, Portugal and ITI/LARSyS, Instituto Superior Técnico, University of Lisbon, Portugal
3. School of Computing and Communication, Lancaster University, United Kingdom
4. School of Design, Northumbria University, United Kingdom