In an A-B design, what does the 'B' refer to?

In an A-B design, the 'B' specifically refers to the treatment phase of the experiment. An A-B design is a simplified form of an experimental analysis where 'A' denotes the baseline phase, which is the measurement period where no intervention or treatment is applied. This initial phase establishes the starting point or normal condition of the subject being studied. When the 'B' phase is introduced, it represents the application of a specific intervention or treatment meant to assess its effect.

This type of design enables researchers to observe the changes in behavior, performance, or outcomes that occur as a result of implementing the treatment compared to the baseline conditions established in the 'A' phase. This setup is valuable because it helps to establish causal relationships between the treatment and the observed outcomes, as any changes can be directly attributed to the introduction of the 'B' phase intervention.