The Delta-Scoring Method of Tests With Binary Items: A Note on True Score Estimation and Equating

Abstract

This article presents some new developments in the methodology of an approach to scoring and equating of tests with binary items, referred to as delta scoring (D-scoring), which is under piloting with large-scale assessments at the National Center for Assessment in Saudi Arabia. This presentation builds on a previous work on delta scoring and adds procedures for scaling and equating, item response function, and estimation of true values and standard errors of D scores. Also, unlike the previous work on this topic, where D-scoring involves estimates of item and person parameters in the framework of item response theory, the approach presented here does not require item response theory calibration.