Although a good rational number understanding is of crucial importance for learners' general maths achievement, many learners have misconceptions about fractions. An often described misconception is that a fraction's numerical magnitude increases when its denominator, numerator, or both increase. The present intervention study investigated how…

The big-fish-little-pond effect (BFLPE) model predicts students' academic self-concept to be negatively predicted by the achievement level of their reference group, controlling for individual achievement. Despite an abundance of empirical evidence supporting the BFLPE, there have been relatively few studies searching for possible moderators.…