Kettler, R. J. (2015). Adaptations and access to assessment of Common Core content . Review of Research in Education , 39 (1), 295–330. https://doi.org/10.3102/0091732X14556075

This literature review presents a comprehensive discussion of access issues, providing both breadth and depth. Broadly, the researcher explains concepts related to accommodations, including accessibility, modification, access and target skills, and test theory terms such as reliability, construct validity, and construct-irrelevant variance. Deeply, the researcher reviews empirical research questions and delves into findings associated with these broad themes, and frames the discussion in the current context of "Common Core" content testing. This summary emphasizes assessment accommodations issues, such as accommodations taxonomies and categories, the differential boost hypothesis, and some overall impact findings reported by the researcher, including for oral delivery, extended time, and bundles of multiple accommodations.

This is a literature review of several sets of studies, including those pertaining to impacts of modifications as well as impacts of accommodations. [This summary emphasizes assessment accommodations research findings.] The researcher coalesced three literature review efforts (Fuchs, Fuchs, & Capizzi, 2005; Sireci, Scarpati, & Li, 2005; and NCEO's biennial accommodations literature review reports, 2007, 2010, 2012), and synthesized differential boost findings for three commonly-provided accommodations: oral delivery by in-person reader (also called "read aloud"), extra or extended time, and multiple/bundled accommodations. The number of studies' findings identified numbered at least 30 for oral delivery, 24 for extended time, and 15 for accommodations bundles. Additional selected studies (as noted in the three literature reviews) were also described when they elaborated or otherwise pertained in some way to construct validity. Participants were students with and without disabilities, and ranged from elementary through secondary levels.

This is a review of empirical literature about the effects of selected accommodations used during assessments, including large-scale standardized assessments of mathematics, reading, and science in K–12 education.

The researcher reported about the findings of several sets of studies on the separate impacts of oral delivery, extended time, and accommodations bundles, including findings pertaining to the differential boost hypothesis. Detailing at least 30 studies on oral delivery—19 of which were experimental—he noted that the findings of 17 of the 30 studies indicated that oral delivery supported improved scores for students with disabilities. The researcher specified that 11 of the 19 experimental studies yielded evidence of differential benefits of oral delivery for students with disabilities in comparison to students without disabilities. An additional four studies (of the 30) indicated that oral delivery did not invalidate the constructs tested, and one of these studies yielded that only a few items on a reading comprehension test were affected by oral delivery. The researcher took care to state "The existing body of research indicates that a read-aloud accommodation is likely to be appropriate on a test of mathematics but not on a test of reading" (p. 318), and that use of oral delivery to assessments of reading comprehension should be carefully considered. Reviewing at least 24 studies on extended test time, the researcher reported that the findings of 11 studies demonstrated positive impacts of extended time for students with disabilities. Further, the 19 studies examining differential boost yielded findings of eight studies supporting differential benefits of extended time for students with disabilities over students without disabilities, and three other studies indicated that extended time did not invalidate the test constructs. The researcher concluded from the research that extended test time benefits students with and without disabilities, and that "Extra time appears to be an appropriate accommodation only for students with impairments in processing speed or fluency to use when taking tests that are not intended to measure processing speech or fluency at all" (p. 319). Examining 15 studies on accommodations bundles, the researcher reported that the findings of 10 studies demonstrated the positive impacts of various sets of multiple accommodations for students with disabilities. Further, of the nine studies about differential boost from bundles, six studies' findings supported differential benefits of various accommodations bundles for students with disabilities over students without disabilities. One study (of the 15) which analyzed factor structures indicated that the IEP-provided accommodations bundles did not invalidate the ELA test construct. The researcher concluded that accommodations bundles or packages benefit students with disabilities as designed, yet that there are complications, including that "the interactions of accommodations within each package are largely unknown" (p. 320). The literature review closes with a discussion of assessment accommodations in the context of Common Core content standards, proposing a new paradigm through which to understand practice and research.