Can placement tests inform instructional decisions?

Abstract

Studies of placement tests are typically narrowly concerned with their validation as instruments for the efficient grouping of students. They rarely explore the assumption that placement test content can be related to classroom tasks and so inform instructional decisions. This study focuses on a trial version of the Global Placement Test (GPT), a measure of grammatical knowledge being developed for use in language schools worldwide. The central concern is the extent to which the GPT can enable schools to make valid inferences regarding mastery of the grammatical structures to be taught on the relevant courses and hence guide diagnostic intervention. In this study the GPT, together with another test specifically designed to measure knowledge of grammatical items expressing temporal relations in English, was administered to 1070 EFL (English as a Foreign Language) learners studying in the UK, Greece and Japan. The dimensionality of the GPT as a measurement scale was investigated by IRT and factor-analytic methods. The analysis suggests that item difficulty is affected more by item type than by any inherent linguistic difficulty of the element of grammatical competence being tested. The results cast doubt on whether quick grammar-based placement tests, which traditionally emphasize efficiency and practicality, can provide sufficient information on which to base diagnostic mediation or sequencing of instructional materials.