Standards of Graph Construction in Special Education Research: A Review of their Use and Relevance

Much of the special education literature features single-case experimental designs, which traditionally require researchers to determine functional relations among variables through the visual analyses of line graphs. Evidence suggests factors aside from the data influence visual analysis, including line graph construction. Fields including engineering, behavior analysis, and psychology have historically propagated standards related to the visual data displays to mitigate the effect of arbitrary graph construction on the interpretation of results. Although evidence suggests graphs featured in behavior analytic studies do not observe the standards, the extent to which researchers in special education adhere to longstanding graphing guidelines remains uncertain. The following article provides an overview of graphing standards and examines the adherence of line graphs from 532 issues of 28 distinct special education journals to traditional standards of visual display. Results indicated the majority of special education line graphs deviate from established line graph construction standards in important respects. The discussion centers on the need for updating and disseminating guidelines regarding line graph construction.