Test theory reconceived

Educational test theory consists of statistical and methodological tools to support inference about examinees' knowledge, skills, and accomplishments. Its evolution has been shaped by the nature of users' inferences, which have been framed almost exclusively in terms of trait and behavioral psychology, and focused on students' tendency to act in prespecified ways in prespecified domains of tasks. Progress in the methodology of test theory enabled users to extend the range of inference and ground interpretations more solidly within these psychological paradigms. Developments in cognitive and developmental psychology have broadened the range of inferences we wish to make about students' learning to encompass conjectures about the nature and acquisition of their knowledge. The same underlying principles of inference that led to standard test theory can support inference in this broader universe of discourse. Familiar models and methods-sometimes extended, sometimes reinterpreted sometimes applied to problems wholly different from those for which they were first devised-can play a useful role to this end.