This article describes the development and validation of the new CATSS (Computer Adaptive Test of Size and Strength), which measures vocabulary knowledge in four modalities -- productive recall, receptive recall, productive recognition, and receptive recognition. In the first part of the paper we present the assumptions that underlie the test --…

The first aim of this study was to develop a computer adaptive EFL test (CALT) that assesses test takers' listening and reading proficiency in English with dichotomous items and polytomous testlets. We reported in detail on the development of the CALT, including item banking, determination of suitable item response theory (IRT) models for item…