An Evaluation of DPPXYR Parameters on Multielement Design Functional Analysis Graphs

Abstract

Single-case experimental design (SCED) allows for the identification of a functional relationship between a dependent and independent variable. For individuals who work as Board Certified Behavior Analysts (BCBAs), it is crucial and part of the ethics code that they can interpret SCED graphed outcomes to make data-based decisions. Visual analysis is the primary method to detect outcomes of SCED; however, research suggests graph characteristics may impact the reliability and estimation of intervention effects, specifically the ratio of the x-to-y axes. This study examined how the alteration of the data-points-per-x-to-y-ratio (DPPXYR) influences BCBA’s ability to detect a function in functional analysis multielement graphs. A primary finding was the overall low agreement in BCBAs selecting function compared to the modified visual inspection (MVI). Descriptive results showed participants had highest accuracy in detecting the function when the DPPXYR was 0.09, although the difference across manipulation was minimal.