Three mode comparability studies were conducted on the following Saturday national ACT test dates: October 26, 2019, December 14, 2019, and February 8, 2020. The primary goal of these studies was to evaluate whether ACT scores exhibited mode effects between paper and online testing that would necessitate statistical adjustments to the online…

In preparation for online administration of the ACT® test, ACT conducted studies to examine the comparability of scores between online and paper administrations, including a timing study in fall 2013, a mode comparability study in spring 2014, and a second mode comparability study in spring 2015. This report presents major findings from these…

This paper investigates four methods of linear equating under the common item nonequivalent groups design. Three of the methods are well known: Tucker, Angoff-Levine, and Congeneric-Levine. A fourth method is presented as a variant of the Congeneric-Levine method. Using simulation data generated from the three-parameter logistic IRT model we…

The most critical feature of a common-item nonequivalent groups equating design is that the average score difference between the new and old groups can be accurately decomposed into a group ability difference and a form difficulty difference. Two widely used observed-score linear equating methods, the Tucker and the Levine observed-score methods,…

The Increasing Course Rigor Pilot Project, a joint initiative of the National Governors Association (NGA) Center for Best Practices and ACT, Inc., is one component of Phase Two of the NGA Center for Best Practices Honor States Grant Program. The project, which began in winter 2006 and concluded in summer 2007, was designed to improve the quality…