Validation of a high-stakes test: GA IESOL multiple-choice units

The purpose of this study is the validation of the Listening and Reading units of the Gatehouse Awards (GA) Classic IESOL (International English for Speakers of Other Languages) examination at the CEFR Level B2, as criterion-referenced achievement tests, with the aim of reaching the multi-trait, multi-method approach of the examination. The data sets have been studied to examine the content validity, reliability of the scores and unidimensionality of the construct. Eight forms, four forms per unit, have been analysed using separate exploratory factor analyses, and they revealed excellent values of internal consistency for the listening unit. The reading test construct unidimensionality values are excellent for Versions E, F and G (henceforth VE, VF and VG), and acceptable for Version D (henceforth VD). In addition, a qualitative analysis of items has been performed and correlation analyses between the scores of the students who completed both tests and are positive and significant (0.621; <0.01). Further steps of the study will be the item response theory (IRT) equating procedure of the four versions.