An Investigation into the Vocabulary Size of EST Students at a Japanese University Using VST

This article reports on an investigation into the vocabulary competency of 553 second-year students of science and engineering majors at a Japanese university in 2014 and 2015 by using the Vocabulary Size Test (VST) developed by Nation and Beglar. The VST was given in required English classes where the students are involved in learning the major components of research papers in English by actually writing one. Vocabulary abilities are among the most fundamental competencies needed in writing papers. The measurement of vocabulary development often depends on the use of vocabulary lists or text-based or contextual comprehension of specific words. Although the use of various types of word lists does provide an objective measurement of learners’ vocabulary abilities to a certain extent, criticisms against such a method, e.g. lack of context and the rationale for using selected high-frequency or low-frequency words in different contexts, are also legitimate arguments. Hence, effective measurements of EFL learners’ vocabulary competence need to be addressed further. In this paper, an explanation of VST, the background of choosing this method, and the analysis of the results is provided. A comparison of the results from 2015 and 2014 is also presented