Vertical scales are frequently developed using common item nonequivalent group linking. In this design, one can use upper-grade, lower-grade, or mixed-grade common items to estimate the linking constants that underlie the absolute measurement of growth. Using the Rasch model and a dataset from Curriculum Associates' i-Ready Diagnostic in math in…

Michigan's Great Start Readiness Program (GSRP) is a state-funded pre-K program that serves at risk four-year-old children across the state. Utilizing longitudinal data from 1,394 children in a mid-sized urban school district, we conducted regression analyses and piecewise linear growth models to examine the growth trajectory of GSRP children and…

This study evaluated the forecasting accuracy of trend estimation methods applied to time-series data from computer adaptive tests (CATs). Data were collected roughly once a month over the course of a school year. We evaluated the forecasting accuracy of two regression-based growth estimation methods (ordinary least squares and Theil-Sen). The…