Visual analysis of multiple baseline across participants graphs when change is delayed.

Abstract

A within-subjects group experimental design was used to test whether three manipulated characteristics of multiple baseline across participants (MBL-P) data showing at least a month delayed change in slope affected experts’ inference of a functional relation and agreement on this judgment. Thirty-six experts completed a survey composed of 16 MBL-P graphs. Graphs with steep slopes, once change began, were far more likely to be judged as showing a functional relation. Generally, experts disagreed with each other regarding functional relation judgments. Implications for the types of dependent variables that fit the requirements of MBL-P are discussed.