Conditional Scale-Score Standard Errors of Measurement under Binomial and Compound Binomial Assumptions

Abstract

This article develops two procedures for estimating individual-level conditional standard errors of measurement (SEMs) for scale scores, assuming tests consist of dichotomously scored items. Using binomial model assumptions, one procedure provides a scale-score analogue of Lord’s raw-score SEM. Assuming a compound binomial model, another procedure provides a scale-score analogue of Feldt’s raw-score SEM. These two procedures are compared to a polynomial procedure and a procedure developed by Feldt and Qualls using data from the Iowa Tests of Basic Skills.