Introduction

Computer-based testing (CBT) has become a viable and well-developed method for administering a variety of tests in many different contexts. Various achievement, psychological, licensure, and certification tests have all benefited from computerization. The emergence of sophisticated computer [Page 259]technology has enabled the implementation of measurement models that were proposed theoretically years ago.

The underpinnings of CBT are grounded in item response theory (IRT), which began to develop in the 1960s (Birnbaum, 1968; Rasch, 1960) and reached a relatively mature state by the 1980s (Lord, 1980). However, the recent expansion of operational CBT programs has introduced challenges that have considerably expanded the psychometrics supporting CBT. The purpose of this entry is to provide an overview of CBT, including its advantages, the psychometric models that support it, and ...