“…To assess criterion validity, we used several simple self-report selfregulation variables reflected in behavior (time management of daily activities and schoolwork, and regularity of schoolwork), school performance variables, and a more complex externally assessed metacognitive knowledge task. The selection of variables was based on (meta-analytic) research on the positive association of school performance with time management, regularity of schoolwork (Cyril, 2015;Núñez et al, 2015;Aeon et al, 2021), and metacognitive knowledge (Gomes et al, 2014;Ergen and Kanadli, 2017;Stephanou and Mpiontini, 2017;Simons et al, 2020). We recorded average school grade in the previous year, binarycoded involvement in school and out-of-school extracurricular activities, and responses to single-item measures (all with 5-point Likert-type scales) regarding time management of daily activities, schoolwork, learning for a test, and regularity of studying.…”