A systematic literature review of randomization procedures within single-case research designs

Area of Science:

• Educational Research Methods
• Single-Case Research Design

Background:

• Single-case research designs (SCRD) are crucial for evaluating interventions in education.
• Randomization procedures enhance the internal validity of SCRD by minimizing bias.

Purpose of the Study:

• To systematically review the utilization and reporting of randomization procedures in educational SCRD.
• To identify trends in the application of randomization over a 12-year period (2010-2022).

Main Methods:

• Systematic literature review of 717 documents (articles, dissertations, theses) published between 2010 and 2022.
• Analysis of the types and frequency of randomization procedures employed in educational SCRD.

Main Results:

• A consistent increase in the use of randomization procedures in educational SCRD was observed.
• Multiple baseline and alternating treatments designs were the most frequent contexts for randomization.
• Within-intervention case randomization was the most commonly reported procedure, followed by phase-order, between-intervention case, and intervention start-point randomization.
• Randomization tests were reported in 8% of the reviewed studies.

Conclusions:

• The findings highlight a growing trend and provide practical implications for researchers regarding the application and reporting of randomization in educational SCRD.
• Guidance is offered on selecting appropriate student outcomes and educational settings for implementing randomization within SCRD.