2.2. MeasuresThe data collections were conducted by class teachers according towritten instructions. The students worked individually on bookletsconsisting of cognitive tasks and beliefs questionnaires, 4 × 45 min inthe fourth grade, and one 90-minute session in the sixth grade. Onlycognitive items, which were identical for both age groups were used inthis study. The number of items per task type, and the reliabilities of thetest for both age groups are presented in Table 1. The reliabilities wereacceptable.