The present study aimed to validate a 70-item Korean bilingual version of the Vocabulary Size Test (VST) using Rasch modeling. The goal was to assess the applicability of this Korean version of the VST for Korean learners of English in an English as a foreign language (EFL) context by examining validity evidence based on Messick’s framework. Specifically, the study focused on the content, substantive, and external aspects of construct validity. However, the findings provided weak evidence supporting the utility of the VST as a measure of receptive vocabulary for Korean EFL learners. The test was deemed too easy and lacked the ability to effectively differentiate among varying levels of second language proficiency, with many test items exhibiting unexpected behavior. Additionally, the VST showed a weak correlation with another measure of second language proficiency. In light of these findings, the study offers specific recommendations for improving the test's validity and usefulness.

The present study aims to investigate the direct and indirect contributions of Korean EFL college students’ L2 receptive and productive vocabulary knowledge to their L2 writing performances by using a structural equation modeling (SEM) analysis with a goal to explore the pathways of vocabulary knowledge to writing. Data from 178 students were collected through tests of receptive and productive vocabulary breadth and depth, a writing test and a reading test. In testing a hypothesized model on the roles of receptive and productive vocabulary in writing, the results of the SEM analysis reveal the direct role of productive vocabulary in writing. The indirect role of receptive vocabulary on writing was observed through the mediating role of productive vocabulary or reading ability due to the direct contribution of receptive vocabulary to both productive vocabulary and reading and that of productive vocabulary and reading to writing. Findings from the study shed light on the relations of L2 receptive and productive vocabulary knowledge with L2 writing abilities, suggesting potential benefits of both receptive and productive vocabulary learning for L2 writing.

This article reports on a study that compared EFL freshman university students’receptive and productive recall vocabulary knowledge and their ability to use that knowledge, as it remains unclear in the literature to what extent knowledge of vocabulary, especially productive knowledge, is indicative of learners’ ability to use vocabulary to communicate. The study first measured the vocabulary size of 169students from 24 majors. Next, deeper meaning word knowledge and vocabulary userelated knowledge were assessed by administering depth tests to 51 of the students who completed the size tests. The study found that the participants were able to use only 60.3% of the words that were known receptively and productively on the size tests, and that receptive deeper meaning vocabulary knowledge was 43.0% greater than productive knowledge. Finally, the study results support the concept of a vocabulary knowledge continuum, but highlight the importance of including both receptive and productive knowledge, as they were found to develop in a dissimilar manner.