64th ISI World Statistics Congress - Ottawa, Canada

64th ISI World Statistics Congress - Ottawa, Canada

Analysis of a Grade 5 Reading Comprehension Assessment: Examining Item Invariance and Performing Test Equating


64th ISI World Statistics Congress - Ottawa, Canada

Format: CPS Abstract

Keywords: dif, equating, rasch

Session: CPS 16 - Teaching statistics II

Monday 17 July 4 p.m. - 5:25 p.m. (Canada/Eastern)


The Assessment, Curriculum, and Technology Research Centre (ACTRC) administered an English Reading Comprehension Test to Grade 5 students in two Philippine regions in 2018 and 2019. To ensure that the achievement scores of the students in both groups are comparable (i.e., on the same scale), ACTRC intends to analyze them using linear equating methods for nonequivalent groups with anchor test. Thirty-two common items were administered to both groups of students and the Rasch model is fitted to the item response data. Before proceeding to test equating, differential item functioning (DIF) analysis using Wald test is employed to detect possible violations of item invariance between the two groups of students. Preliminary results reveal that four common items are flagged as DIF items. Careful examination of these items is conducted to determine possible item bias. Afterwards, three equating methods, namely, concurrent scaling, shift and scale, concurrent, and anchoring methods are employed and compared with each other to equate the two assessments based on the remaining common items.