Examining and Enhancing the Methodological Quality of Nonconcurrent Multiple-Baseline Designs

In this article we respond to the recent recommendation of Slocum et al. ( 2022 ), who provided conceptual and methodological recommendations for reconsidering the credibility and validity of the nonconcurrent multiple-baseline design. We build on these recommendations and offer replication and randomization upgrades that should further improve the status of the nonconcurrent version of the design in standards and single-case design research. Although we suggest that the nonconcurrent version should be an acceptable methodological option for single-case design researchers, the traditional concurrent multiple-baseline design should generally be the design of choice.