A multiple-sequence variant of the multiple-baseline design: A strategy for analysis of sequence effects and treatment comparison.

The design logic and potential uses of a variant of the multiple-baseline design that implements multiple treatment sequences is described. The multiple-baseline multiple-sequence (MBL-MS) consists of 2 or more multiple-baseline designs that are interlaced with one another and include all possible sequences of the treatments. The counterbalanced sequencing of treatments permits observation of any sequence effects that are present. This sequencing can permit identification of an optimal treatment sequence and comparison of relative efficacy of treatments. This variation of the multiple baseline also extends the available treatment comparison designs by providing an additional design that does not require reversal or treatment or sequence effects. Because of vulnerability to ceiling and floor effects, the MBL-MS design appears to be primarily useful for the comparison of treatments that take several sessions to produce an optimal level of responding or when the behavior is not subject to floor or ceiling effects. (PsycINFO Database Record (c) 2011 APA, all rights reserved)