[1] These methods form the heart of the data collection and analytic code of behavior analysis.
Behavior analysis is data driven, inductive, and disinclined to hypothetico-deductive methods.
Variants on the AB design introduce ways to control for the competing hypotheses to allow for stronger conclusions.
[6] Further ethics notes: It may be unethical to end an experiment on a baseline measure if the treatment is self-sustaining and highly beneficial and/or related to health.
Control condition participants may also deserve the benefits of research once all data has been collected.
[8] Two treatments are alternated in rapid succession and correlated changes are plotted on a graph to facilitate comparison.
[9] Multi-element designs are typically used in Single-subject research to accurately test multiple independent variables at once.
Differential changes that occur to each behavior, person or in each setting help to strengthen what is essentially an AB design with its problematic competing hypotheses.
In addition to multiple baseline designs, a way to deal with problematic reversibility is the use of repeated acquisitions.
The combined design has arisen from a need to obtain answers to more complex research questions.