Balancing Test Accuracy and Security in Computerized Adaptive Testing
This work addresses test security issues in personalized educational testing, but it is incremental as it modifies an existing framework.
The paper tackled the problem of high question exposure and test overlap rates in bilevel optimization-based computerized adaptive testing (BOBCAT), which affects test security, by introducing a constrained version (C-BOBCAT) that trades off test accuracy for improved security, showing effectiveness through experiments on two real-world adult testing datasets.
Computerized adaptive testing (CAT) is a form of personalized testing that accurately measures students' knowledge levels while reducing test length. Bilevel optimization-based CAT (BOBCAT) is a recent framework that learns a data-driven question selection algorithm to effectively reduce test length and improve test accuracy. However, it suffers from high question exposure and test overlap rates, which potentially affects test security. This paper introduces a constrained version of BOBCAT to address these problems by changing its optimization setup and enabling us to trade off test accuracy for question exposure and test overlap rates. We show that C-BOBCAT is effective through extensive experiments on two real-world adult testing datasets.