Detecting False Positives in A-B Designs: Potential Implications for Practitioners. (September 2013)

• Record Type: Journal Article
• Authors: Krueger, Tyler K.; Rapp, John T.; Ott, Lisa M.; Lood, Elizabeth A.; Novotny, Marissa A.
• Is Part Of: Behavior modification. Volume 37:Number 5(2013)
• Page Start: 615
• Page End: 630
• Publication Date: 2013-09
• Subjects: A-B designs -- experimental control -- experimental design -- false positives -- visual analysis; Behavior modification -- Periodicals; Behavior therapy -- Periodicals; 153.85
• DOI: 10.1177/0145445512468754
• Languages: English
• ISSNs: 0145-4455

Abstract

This study evaluated the probability of generating false positives with A-B graphs. We generated 1, 000 graphs consisting of three stable A-phase data points at 25% and three random B-phase data points; 1, 000 graphs consisting of three stable A-phase data points at 50% and three random B-phase data points; and 1, 000 graphs consisting of three random A-phase data points and three random B-phase data points. Results indicate that false positives were produced for (a) a relatively high percentage of graphs containing nonrandom data points in the A phase and (b) less than 2% of graphs containing random data points in both the A and B phases. These findings suggest that A-B designs may be a stronger clinical tool for evaluating the effects of interventions than previously recognized.