1. UCI Teaching and Learning Research Center, University of California, Irvine, 3000 Anteater Instruction and Research Building, Irvine, California 92697-4150, United States
2. Center of Science and Math in Context, University of Massachusetts Boston, Wheatley Hall, Fourth Floor, Room 181, 100 Morrissey Boulevard, Boston, Massachusetts 02125-3393, United States
3. School of Information, University of Michigan, 105 South State Street, Room 4435, Ann Arbor, Michigan 48109-1285, United States
4. Hector Research Institute of Education Sciences and Psychology, University of Tübingen, Europastraße 6, Room 308, 72072 Tübingen, Germany
5. Department of Educational Psychology, University of Minnesota, 174 Education Science Building, 56 East River Road, Minneapolis, Minnesota 55455, United States