1. Faculty of Education and Psychology, University of Jyväskylä, P.O. Box 35, 40014 Jyväskylä, Finland
2. Faculty of Educational Sciences, University of Helsinki, Siltavuorenpenger 5, P.O. Box 9, 00014 Helsinki, Finland
3. Valteri Centre for Learning and Consulting, Kukkumäentie 27, 40600 Jyväskylä, Finland
4. Department of Special Needs Education, University of Oslo, Blindern, Postboks 1140, 0318 Oslo, Norway