NCEO recently published A Summary of the Research on the Effects of K–12 Test Accommodations: 2018 (NCEO Report 423). This report summarizes the research on test accommodations for U.S. elementary and secondary students (K–12) published in 2018. The academic literature described here encompasses empirical studies of performance comparability, investigations into accommodations use, implementation practices, and perceptions of the effectiveness of accommodations. During 2018, 11 research studies were published on the topic of testing accommodations in the U.S. elementary and secondary education system.

NCEO has published several syntheses of the research on test accommodations. Separate reports are available which summarize the research published in various years. This series of summaries of the research on effects of test accommodations go back to 1999: 2017, 2015-2016, 2013-2014, 2011-2012, 2009-2010, 2007-2008, 2005-2006, 2002-2004, 1999-2001.