Blocked AB Design — Blocked AB Single-Subject Experimental Design

The Blocked AB Design applies the logic of randomized block experimental design to the classic single-subject AB framework. Observation sessions are organized into blocks — matched sets of time points or contextual units — and the assignment of baseline (A) and treatment (B) phases is randomized within each block. This controls for nuisance time-based variability while preserving the interpretive simplicity of the fundamental two-phase single-case structure.