Development and Validation of a Diagnostic Grammar Test for Japanese Learners of English

Abstract

This article reports on the development and validation of the English Diagnostic Test of Grammar (EDiT Grammar) for Japanese learners of English. From among the many aspects of grammar, this test focuses on the knowledge of basic English noun phrases (NPs), especially their internal structures, because previous research has indicated the difficulty faced by Japanese learners of English in acquiring these phrases. The results of the examination of the pilot and revised tests suggest that the revised test is generally appropriate in terms of item discrimination, distractor function, reliability, and the difficulty of NP groups. Overall, the EDiT Grammar provided favorable evidence for the validity in interpreting the test scores in the case of a fairly low-stakes diagnostic test.