The effect of content homogeneity and anchor length on the accuracy of dichotomous multi-level mathematics test equating according to anchor- test- non equivalent groups design

The present study aimed at investigating the effect of content homogeneity and anchor length on the accuracy of dichotomous multi-level mathematics test equating according to anchor- test- non equivalent groups design. Vertical equepercentile equating by using the standard error of equepercentile equating method was applied in this study on nine graders scores and ten graders scores through two achievement mathematics tests. The main variables of the tests were content homogeneity and anchor length. The sample of the study consisted of (776) examinees, from grades nine and ten in the Directorate of Education of Al-Mafraq District. The schools were chosen randomly. The Results of the study indicated that the highest degree of equating accuracy was achieved using the anchor test whose content was homogeneous and more than (20) items. Whereas the value of the standard error of equipercentile equating equal 0.851. In the light of the study findings, a number of recommendations were suggested.