A New Approach to Simultaneous Latent Ability & Test Difficulty Estimation

Abstract

A new method of binary test results evaluation when checking a latent ability is proposed. We examine the case where a population of objects is tested by a set of test items having different, but unknown beforehand levels of difficulty, and one needs to evaluate both the intrinsic abilities of these objects and the level of difficulty of every test items. We assume that the same scale invariant item response model applies to all objects under study.