A practitioner's guide to conducting and analysing embedded randomized single-case experimental designs

ABSTRACT

Single-case experimental designs (SCEDs) are a class of experimental designs suited for answering research questions at an individual level. The main designs available in SCED research are phase designs, multiple baseline designs, alternation designs, and changing criterion designs. Embedded designs, also referred to as combination or hybrid designs, consist of one of these basic designs forms embedded in another design (e.g., a changing criterion design embedded in a multiple baseline design). Systematic reviews of SCEDs have repeatedly indicated that embedded designs are frequently used in applied SCED research. In spite of their popularity, specific recommendations on the conduct and analysis of embedded SCED designs are lacking to date. The purpose of the present article is therefore to provide guidance to applied researchers wishing to conduct embedded SCED designs in terms of design options, design requirements, randomization, and data analysis.

KEYWORDS:

• Single-case experimental designs
• Single-case embedded designs
• Single-case combination designs
• Single-case hybrid designs
• Randomized single-case experimental designs‌

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notes

1 Rating the stronger of the designs when assessing the methodological quality of an embedded design is one option (Tate et al., 2015). A more detailed approach is to assess separately each design and/or participant within a study or replication (as in the review by Perdices et al., 2019), leading to several overall scores of methodological quality if a scale is used for quantification. This may be considered the preferable practice (R. Tate, personal communication, 11 January 2022).

2 Several reflections on the distinction between primary and secondary designs will be discussed in the section entitled “General notes on steps 1 and 2.”

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Funding

The author(s) reported there is no funding associated with the work featured in this article.