Validation of subtests on fractions in Examath 8-15

Abstract

Knowledge on fractions and abilities to use them are essential for an accomplished mathematical development and predicts the future algebraic abilities. To investigate knowledge on fractions thus is precious during a mathematical assessment of a teenager. The first aim was to investigate the validity of five subtests on fractions proposed for 13-15-year- old teenagers in Examath 8-15 – the only French-speaking evaluation tool of these skills existing for this age. A total of 22 teenagers of grade 8 without any difficulty were administered these subtests as well as a subtest on fractions of Tedi-math Grands. The second aim was to pursue the study of validity of the subtest Number Line Fraction and to develop standardized norms. For that purpose, a total of 84 8-9-grade teenagers without any difficulty and 28 teenagers with mathematical learning difficulty were administered this subtest. The results showed a good concomitant validity, a good validity of construct in relation with the individual characteristics, a good inter-subtests consistency and a good temporal reliability of the five subtests. For the LNF subtest, the results highlighted a good inter-items consistency, a good discriminating validity, a good sensibility and specificity. In conclusion, the study allows to confirm that the five tests relative to fractions of Examath 8-15 have good psychometric properties.