1. Department of Education Sciences “G.M. Bertin”, Alma Mater Studiorum University of Bologna, Bologna, Italy
2. Department of Social Sciences, Technical University of Kaiserslautern, Kaiserslautern, Germany
3. Department of Psychology “R. Canestrari”, Alma Mater Studiorum University of Bologna, Bologna, Italy
4. London Psychometric Laboratory, University College London, London, UK