This study was set to cross-validate a bilingual Persian-English version of the Vocabulary Size Test (VST) against the monolingual English version and compare Iranian EFL learners' performance on the two versions. Various bilingual versions of the VST have been developed based on the assumption that bilingual versions are not affected by the…

The search for fairness in language testing is distinct from other areas of educational measurement as the object of measurement, that is, language, is part of the identity of the test takers. So, a host of issues enter the scene when one starts to reflect on how to assess people's language abilities. As the quest for fairness in language testing…

With the rising concerns over the fairness of language tests, Differential Item Functioning (DIF) has been increasingly applied in bias analysis. Despite its widespread use in psychometric circles, DIF is facing a number of serious problems. This paper is an attempt to shed light on a number of the issues involved in DIF analysis. Specifically,…

This paper reports an attempt to develop and validate a bilingual Persian version of the Vocabulary Size Test (VST). Due to the particular educational system in Iran, there is a dire need for a test that can effectively estimate English learners' vocabulary sizes. Previous research (Nguyen and Nation, 2011) has indicated that bilingual versions of…