THE COMPARISON OF ITEM DISCRIMANTION PARAMETERS ESTIMATED FROM DIFFERENT TEST THEORIES

Abstract

The main purpose of this study is to compare the item discrimination parameters estimated from Classical Test Theory(CTT) and Nonparametric Item Response Theory(NIRT) and to analyze the similarities of the estimations. For this purpose, a correlational research methhod included in the quantştative approach was preferred. The study group of this research was composed of 226 class and brach teachers who are in service at primary and elementary public schools. The data of the study was gathered by using the teachers’ attitude scale towards students’ uniforms composed of 38 items. Item discrimination parameters were calculated using total scores obtained from the scales considering the two test approaches. The item discrimation parameters estiamated from CTT by point-biserial correlation coefficients. For NIRT, scalability coefficents were estimated. The data were analyzed via R program with “ctt” and “mokken” packages and SPSS 22.0. The correlations between the parameters were found significant and very high. Considering the findings, while estimating the item discrimination parameters, CTT and NIRT approaches may be used interchangeably.