Construction and Validation of Polytomously-Scored Multiple-Choice Items in Mathematics

Abstract

This study constructed and validated multiple-choice items using dichotomous and polytomous scoring in Mathematics. It examined the difficulty and discrimination indices of polytomous items using dichotomous scoring; the thresholds and discrimination indices of the items using polytomous scoring (GRM) and compared the discrimination indices of the items in both scoring formats. The population of the study comprised secondary schools' students in Lagos State, Nigeria. The sample consisted of 1015 students; these were selected from two Education Districts (EDs) from the six EDs in the state using simple random sampling technique. The results revealed that more than half of the items had high difficulty indices with corresponding high discrimination indices, using dichotomous scoring. It showed the items had moderate transition locations and discrimination indices, using polytomous scoring. It also indicated that there was a significant difference in the discrimination indices of both scoring methods.

Keywords

• dichotomous scoring
• polytomous scoring
• difficulty index
• discrimination index
• transition locations