Commentary on Slocum et al. (2022): Additional Considerations for Evaluating Experimental Control.

Area of Science:

• Behavior Analysis
• Research Methodology
• Experimental Design

Background:

• Slocum et al. (2022) proposed nonconcurrent multiple baseline designs (NCMBDs) offer internal validity similar to concurrent multiple baseline designs (CMBDs).
• Previous research has debated the internal validity and utility of NCMBDs compared to CMBDs.
• Evaluating the strength of experimental designs requires careful consideration of their ability to establish valid and accurate results.

Purpose of the Study:

• To provide further support for the assertion that NCMBDs possess internal validity comparable to CMBDs.
• To advocate for a more nuanced approach in evaluating the strength of experimental designs, moving beyond strict adherence to rules.
• To explore additional considerations for determining the relative strengths of NCMBDs and CMBDs.

Main Methods:

• The study offers theoretical arguments and logical extensions of previous findings.
• It emphasizes the low probability of within-tier comparisons failing to detect confounds in NCMBDs.
• The authors extend existing logic to question the necessity of staggered implementation in all NCMBD cases.

Main Results:

• Further empirical and theoretical support is provided for the internal validity of NCMBDs.
• The analysis suggests that staggering the independent variable implementation across tiers may not always be necessary.
• An argument is presented that NCMBDs can provide verification within baseline logic, contrary to some prior claims.

Conclusions:

• NCMBDs can achieve high internal validity, comparable to CMBDs, when implemented thoughtfully.
• A flexible, nuanced approach to design evaluation is more beneficial than rigid adherence to specific design features.
• While supporting NCMBDs, the authors acknowledge that CMBDs may facilitate broader dissemination in some contexts.