Bouck, E. C., Bouck, M. K., & Hunley, M. (2015). The calculator effect: Understanding the impact of calculators as accommodations for secondary students with disabilities . Journal of Special Education Technology , 30 (2), 77–88. https://doi.org/10.1177/0162643415617371

The use of a graphing calculator was investigated using a single subject research design, following an A-B-A-B pattern of testing while providing the accommodation, with a baseline, intervention, removal of intervention, then replication of intervention.

Three students with disabilities in grade 7 and four students in grade 8 who received grade-level mathematics instruction in pullout classrooms from a special education teacher. All participants had calculators listed on their individualized education program (IEP) plans. The grade 7 students' disabilities included two students with other health impairments and one student with a learning disability. The grade 8 students included two with other health impairments, one with autism spectrum disorder, and one with emotional impairment. Additional demographic data, and other academic and disability information, were reported for each student, at a school in a rural town in the Midwest (U.S.).

Researchers created 20 assessments for each of the two grade levels (grades 7 and 8), focused on the Common Core State Standards, drawing from the state assessment's released items and other sample items. Each assessment had eight items, with four computation problems and four word problems. Data collected included the number of correct responses, as well as the number of items attempted. Participants also responded to a series of social validity survey questions using a Likert-type rating scale.

Descriptive data indicated that participants scored higher on test items when using the calculator than when not using it. Most students attempted all, or nearly all, items in all four test phases, but for those who did not do so, both of them attempted more with the calculator than without. No different pattern of benefit from using calculators was demonstrated for solving computation or word problem item types correctly. Percentage of nonoverlapping data between the test phases served as a nonparametric form of effect size. Each participant's relative degree of success (or lack of success) was reported separately. The grade 7 students all evidenced a small effect of using the calculator, while half of the grade 8 students showed a small effect and the other half showed a moderate effect of using the calculator. Nearly all participants' scores were analyzed to be variable across test phases, and the calculator was deemed a questionable or unreliable intervention in many cases. Participants reported that they liked calculators, and that they helped, with both types of problems; however, there was one exception to this perception. All students in grade 7 indicated that they do not need to use calculators in the future, but the grade 8 students indicated that they do need to use calculators in the future.