Assessing the Quality of a Newly Designed Vocabulary Test for Vietnamese EFL Learners: A Rasch-based Analysis

Abstract

Test development involves many required stages, including examining the psychometric characteristics of the test and each test item. This study describes the development of an English vocabulary test designed for EFL learners in Vietnam and provides an analysis using the Rasch model to evaluate the test quality and test items. The data was collected from 202 students from a Vietnamese university and analysed with the use of the Conquest computer program. The results show that the test had high reliability. Four out of 50 items were removed from the test as not fitting the Rasch model. 36 items were ranked very good, and 10 items require some revision efforts for better distractors. The paper is expected to contribute to the wide application of the Rasch model in the practices of test development and suggest the development of more reliable instruments for EFL learners to assess their vocabulary.

Keywords

• Test development
• English vocabulary test
• EFL learners
• Rasch model