1. Customer Satisfaction Center, University of Siena, Italy
2. Laboratory of Psychometrics, “Gabriele d’Annunzio” University of Chieti-Pescara, Italy
3. Department of Neuroscience and Imaging, “Gabriele d’Annunzio” University of Chieti-Pescara, Italy
4. Leonardo da Vinci Telematic University, Italy
5. Research Department of Clinical, Educational and Health Psychology, University College London, UK