Psychology Roots 483
A-B-A-C-A design
a type of single-case design having five consecutive phases: a baseline condition in which no treatment is present (Phase A), a treatment condition in which a manipulation is introduced (Phase B), a return to the no-treatment condition (Phase A), a new treatment condition in which a different manipulation is introduced (Phase C), and a subsequent return to the no-treatment condition (Phase A). The A-B-A-C-A design helps to establish the effects on the dependent variable of alternating treatments by evaluating the relationship between the introduction and removal of one treatment and a subsequent introduction and removal of a second treatment.
