An Application of 3PL IRT Model to Validating a Vocabulary Levels Test

陳麗如(Li-Ju Chen) ； 曾文鐽(Wen-Ta Tseng)

《應用英語期刊》 5期 (2012/12) Pp. 93-109

https://doi.org/10.29691/JAE.201212.0005

並列摘要

Due to the vital role of a substantial vocabulary size in language teaching, vocabulary size tests were required to monitor learners' progress and to assess their achievement in vocabulary learning. This study hence aims to develop a measurement of English vocabulary size in the format of levels test based on the 6,480 reference word list published by College Entrance Examination Center and to validate it in terms of the empirical evidence collected by using three-parameter logistic Item Response Theory Model (3PL IRT model). With the construction and validation of the test, this study further explored the relationship between word frequency and its latent difficulty calibrated by 3PL IRT model. Participants in this study were 1,060 senior high school students. Results showed that the reliability of the test could be observed in its high empirical reliability (0.99) and that the validity was reflected in its good construct validity and hierarchical validity. Besides, fit analysis indicated that the test items were of good quality overall. As to the relationship between word frequency and its latent difficulty, the findings of level latent difficulty suggested that word frequency did not work synergistically with its latent difficulty. With the development of the English vocabulary size measurement and the investigation of level latent difficulty, it is hoped that both educators and learners can gain insight into the vocabulary learning process and thus have a clear view on how to facilitate the achievement of the vocabulary learning goal.

並列關鍵字

Vocabulary Levels Test ； 3PL IRT Model ； vocabulary size ； word frequency