ESTIMATING LATENT ABILITY FROM THE NDT RESULTS, WHEN THE TEST ITEMS DIFFICULTIES ARE UNKNOWN BEFOREHAND

摘要

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