Visual inspection of single-case data is the primary method of interpretation of the effects of an independent variable on a dependent variable in applied behavior analysis. The purpose of the current study was to replicate and extend the results of DeProspero and Cohen (1979) by reexamining the consistency of visual analysis across raters. We recruited members of the board of editors and associate editors for the Journal of Applied Behavior Analysis to judge graphs on a 100-point scale of experimental control and by providing a dichotomous response (i.e., "yes" or "no" for experimental control). Results showed high interrater agreement across the three types of graphs, suggesting that visual inspection can lead to consistent interpretation of single-case data among well-trained raters.
Keywords: data analysis; single-case design; visual inspection.