A Proposal for the Assessment of Replication of Effects in Single-Case Experimental Designs

Abstract

In science in general and, therefore, in the context of single-case experimental designs (SCED), the replication of the effects of the intervention within and across participants is crucial for establishing causality and also for assessing the generality of the intervention effect. Specific developments and proposals for assessing whether an effect has been replicated or not (or to what extent) are scarce, in the general context of behavioral sciences, and practically null in the SCED context. We propose an extension of the modified Brinley plot for assessing how many of the effects replicate. In order to make this assessment possible, a definition of replication is suggested, on the basis of expert judgment, rather than on purely statistical criteria. The definition of replication and its graphical representation are justified, presenting their strengths and limitations, and illustrated with real data. A user-friendly software is made available for obtaining automatically the graphical representation.