measurement invariance

The aim of this study was to provide evidence on the construct validity of the ‘What is Happening in this Class’ (WIHIC) questionnaire in the context of teaching English as a foreign language (EFL) in Iran. The field of language teaching has made a number of claims about the role of language learning environments (particularly the classroom) in L2 acquisition and use, but it does not provide teachers and researchers with reliable and valid instruments to assess the accuracy of these claims. To serve the purpose of the study, a sample of 607 Iranian EFL learners from both university and institute contexts was requested to complete the WIHIC questionnaire, and the obtained data were then submitted to exploratory and confirmatory factor analysis for construct validation. The results indicated that the deletion of one dimension and several items from the original WIHIC questionnaire enhanced its psychometric properties, thus confirming the validity of the questionnaire with six factors. In addition, the psychometric properties of the validated questionnaire were found to be invariant across the teaching context (i.e., university versus institute contexts). The implications of these findings for research on language learning environments are discussed, and some suggestions are made for further validation studies.

Measurement invariance (MI) refers to the degree to which a measurement instrument or scale produces consistent results across different groups or populations. It basically shows whether the same construct is measured in the same way across different groups, such as different cultures, genders, or age groups. If MI is established, it means that scores on the test can be compared meaningfully across different groups. To establish MI mostly confirmatory factor analysis methods are used. In this study, we aim to examine MI using the Rasch model. The responses of 211 EFL learners to the listening section of the IETLS were examined for MI across gender and randomly selected subsamples. The item difficulty measures were compared graphically using the Rasch model. Findings showed that except for a few items, the IELTS listening items exhibit MI. Therefore, score comparisons across gender and other unknown subgroups are valid with the IELTS listening scores.