Mandinach, E. B., Bridgeman, B., Cahalan-Laitusis, C., & Trapani, C. (2005). The impact of extended time on SAT test performance (ETS RR-05-20). The College Board. http://www.ets.org/Media/Research/pdf/RR-05-20.pdf

College Board Research Report No. 2005-8 / ETS RR-05-20

The four testing conditions incorporated standard time, 150% (or 1.5 times standard time), and 200% (or twice the standard time), along with whether each section was separately timed. Test section ordering was also randomized.

A total of 1,929 students in grade 12 from 72 high schools throughout the nation (U.S.) participated. The participants included 264 students with disabilities—including learning disabilities, or attention-deficit hyperactivity disorder (ADHD), or both conditions. Students with and without disabilities were further grouped into varying ability levels.

Participant scores on the SAT Reasoning test comprised the dependent variable.

Results indicated that time-and-a-half with separately timed sections benefits students with and without disabilities was beneficial. The researchers noted, however, that some extra time improves performance, but too much may be detrimental. Results also demonstrated that extra time benefited medium- and high-ability students but provided little or no advantage to low-ability students. The effects of extended-time were more pronounced for the mathematics section of the SAT than other sections. Limitations of the study were reported, and future research possibilities were suggested.