Psychology Roots 216
A-B design
the simplest single-case design, comprising a pretreatment or baseline phase (Phase A) followed by a treatment phase (Phase B). Although it allows for evaluation of the treatment’s effect by comparing the dependent variable during the two phases, the design does not provide evidence of causality because it does not establish a repeated relationship between the introduction and removal of the treatment and a consequential change in the dependent variable (compare A-B-A design).
