Participants were 3675 individuals born in 1990 that had taken both the standardized examinations in mathematics and Icelandic in 2006, and filled out a questionnaire included in the PISA 2006 study.
Þátttakendur voru 3675 einstaklingar fæddir 1990 sem höfðu tekið samræmd próf í íslensku og stærðfræði og svarað PISA könnuninni vorið 2006.