This research brief provides an overview of methods for estimating the size of achievement gaps. Unfortunately many researchers, analysts, and policy-makers use subjective methods (e.g., visual inspection) to evaluate group differences. Another common method is to take the difference between groups in percent proficient, but there are a number of…

An underlying assumption in our current test-based accountability system is that all participating students have an opportunity to learn the tested academic content. For students with disabilities (SWDs), this assumption is stated clearly in federal legislation intended to ensure their access to the same academic standards that define the general…

Longitudinally modeling the growth of students with significant cognitive disabilities (SWSCDs) on alternate assessments based on alternate achievement standards (AA-AAS) presents many challenges for states. The number of students in Grades 3-8 who remain in a cohort group varies over time, depending on the methods used to construct the…