The purpose of this study is to examine the fit of MAP Growth K–2 items involved in a scale alignment study conducted by NWEA to realign the scales underlying the MAP Growth K–2 and MAP Growth 2–5 Reading and Mathematics tests.

This study investigates the impact of three different IRT scaling and equating methods in building an item bank of tests from 23 years of a national licensure exam . The study focuses on several key psychometric issues including scaledriftandequatingerrors.

These studies are conducted based on assumptions under regular conditions for fixed test forms, such as no missing responses and normal distribution of unidimensional ability for a population.