Under the framework of item response theory (IRT) and generalizability (G-) theory, this study examined the effects of item difficulty on rating reliability and construct validity on both the constructed-response (CR) items and essay items on English examinations. The data collected for this study were students' scores and responses on the two…

One major threat to validity in high-stakes testing is construct-irrelevant variance. In this study we explored whether the transition from a paper-and-pencil to a computer-based test mode in a high-stakes test in China, the College English Test, has brought about variance irrelevant to the construct being assessed in this test. Analyses of the…