The Construct Validity of a Language Proficiency Test: a Multitrait Multimethod Approach

 The present study intends to investigate the construct validity of a test which is used for admission purposes. It was conducted with ۳,۳۹۸ participants. These testees took an English language proficiency test as a partial requirement for entering a PhD program in different fields of education at the University of Tehran. This test has three sections consisting of grammar, vocabulary and reading comprehension. To determine the construct validity of the test, the design of multitrait- multimethod (MTMM) was investigated. According to Cronbach and Meehl (۱۹۵۹), in this design and approach to validation more than one trait and more than one method should be used. In the present study, the two traits used were grammar and vocabulary. The two methods employed were multiple choice and contextualization. The results revealed that the test possessed both convergent and discriminant validities. In other words, the same traits tested through different methods had more correlation than different traits tested through the same methods. To collect more evidence for the validity of the test and determine the effect of the methods used, the researchers also conducted two monotrait multimethod analyses: one was grammar being tested through more than one method and the other was vocabulary being tested in more than one way. The effects of methods were also determined.

Keywords:

Construct validity , multitrait-multi-method , convergent validation , discriminant validation , language proficiency test