1. Research and Development; Education Administration, City of Stockholm; SE-112 21 Stockholm Sweden
2. Department of Mathematics and Science Education; Stockholm University; SE-106 91 Stockholm Sweden
3. Department of Behavioural Sciences and Learning; Linköping University; SE-581 83 Linköping Sweden
4. Department of Education; Communication and Learning; University of Gothenburg; Box 300 SE-405 30 Göteborg Sweden