In the fall of 2017, ACT began providing a limited number of supports (also known as accommodations) to English Learner (EL) students in the US taking the ACT® test. The goal of the supports is to remove construct-irrelevant variance in students' scores related to limited English proficiency and allow students to more accurately demonstrate their…

Various applications of item response theory often require linking to achieve a common scale for item parameter estimates obtained from different groups. This article used a simulation to examine the relative performance of four different item response theory (IRT) linking procedures in a random groups equating design: concurrent calibration with…

This manual contains information about the American College Test (ACT) Plan® program. The principal focus of this manual is to document the Plan program's technical adequacy in light of its intended purposes. This manual supersedes the 2011 edition. The content of this manual responds to requirements of the testing industry as established in the…

This research report is a review and analysis of all of the published studies during the past 25+ years (since 1974) in the area of differential validity/prediction and college admission testing. More specifically, this report includes 49 separate studies of differences in validity and/or prediction for different racial/ethnic groups and/or for…