The Ten-Minute Vocabulary Tests for Quick and Rough Estimates of General English Ability of Japanese EFL Learners I

Abstract

The purposes of this research are (1) to investigate whether word frequency of the words used in Mochizuki's (1998) Vocabulary Size Test is highly correlated with difficulty of vocabulary for Japanese EFL learners, (2) to delete the bad test items from 210 items of Mochizuki's test, the weak items of which were judged as misfitting items, overfitting items, or low-discriminant-power items using FACETS (a Rasch model computer program), (3) utilizing the remaining vocabulary items of Mochizuki's test, to create new vocabulary tests having some Forms which are parallel tests with one another for quick and rough estimates of examinees'; general English ability in terms, not of word frequency but word difficulty (item difficulty). The results showed that (1) word frequency was not highly correlated with word difficulty, (2) only 102 test items were left after misfitting items, overfitting items, and low-discriminant-power items were deleted, but the 102-vocabulary-item test still worked well to estimate general English tests' scores almost as well as the original 210-item vocabulary test did, and (3) three Forms of the new vocabulary tests based on word difficulty order with only 32 items which can be conducted in less than 10 minutes were developed for quick and rough estimates of examinees' general English abilities, and the concurrent validity of each Form of the new vocabulary tests were theoretically confirmed.