دانلود رایگان مقاله اندازه گیری اندازه لغات انگلیسی از طریق تست تطبیقی کامپیوتری

Abstract

Measuring English vocabulary size in EFL contexts normally requires a large number of test items and relies on paper-and-pencil (P&P) formats. The aim of this study was to examine the feasibility and practicality of computerized adaptive testing (CAT) as an alternative to measuring English vocabulary size. Differing from the fixed, uniform item sequences in conventional P&P tests, CAT adopts a dynamic, adaptive item selection procedure to optimally target the interim ability estimate and reach the convergence, resulting in a shorter, putatively more efficient test-taking process. The study involved three phases. The first phase built up a vocabulary item bank using the Rasch model, which was used for administering the CAT study; the second phase undertook an experiment to compare various termination conditions in both the P&P and CAT contexts; the third phase examined the accuracy and efficiency of the two test modes in classifying test-takers into mastery and non-mastery groups. The results show that testing EFL learners' English vocabulary size with CAT requires only one third of the items in the item bank while still producing comparable vocabulary size estimates to the original test calibrated by all the 180 items in the item bank. The study also demonstrates that CAT can be more efficient and precise in classifying test-takers into mastery and non-mastery groups. These research findings suggest that CAT has great potential in efficiently and precisely measuring EFL learners' English vocabulary size. The relevant research and pedagogical implications are further discussed.

5. Conclusion

In a conventional mode of P&P test delivery, being assessed for 180 vocabulary items to gauge English vocabulary size can be daunting and de-motivating for most test-takers. The current study shows that testing EFL learners' English vocabulary size using CAT can reduce the needed test items by up to two-thirds while still producing fairly close and comparable vocabulary size estimates to the ones using all of the 180 items. In the dynamic mode of CAT test administration, the process of item selection by CAT is tailored to test-takers' provisional vocabulary size estimates. This study suggests that CAT has incredible potential in not only efficiently measuring EFL learners' English vocabulary size but also precisely diagnosing whether they have mastered a targeted vocabulary size threshold. The results of the study constitute a prima facie rationale for implementing CAT in both assessing and diagnosing EFL learners' English vocabulary size. This study, however, is not without limitations. First, it is limited in its scope of item selection from a prescribed curriculum. Researchers need to move one step further to refer to other standardized vocabulary size tests and run more replication studies. Second, the study is also limited in its coverage of word knowledge. Word knowledge is multi-faceted in nature. Although this pioneering study shows the potentials of using CAT to measure the receptive dimension of form-meaning links of words, its utility in measuring other facets of word knowledge such as collocation or register has yet to be determined. Future research efforts should therefore be dedicated to these two lines of research inquiries.