Double-blind AB Design — Double-blind AB Single-Subject Experimental Design

The double-blind AB design is a single-subject experimental approach that sequences a baseline phase (A) and an intervention phase (B) while concealing phase allocation from both the participant and the outcome assessor. It merges the idiographic focus of single-case methodology with the bias-control mechanism of double-blinding, making it especially useful in clinical rehabilitation, pain research, and behavioral medicine when objective measurement of an individual's response to treatment is the primary goal.