Vocabulary size measures serve important functions, not only with respect to placing learners at appropriate levels on language courses but also with a view to examining the progress of learners. One of the widely reported formats suitable for these purposes is the Yes/No vocabulary test. The primary aim of this study was to introduce and provide…

When a test is adapted from a source language (SL) into a target language (TL), the two forms are usually not psychometrically equivalent. If linking between test forms is necessary, those items that have had their psychometric characteristics altered by the translation (differential item functioning [DIF] items) should be eliminated from the…