An Introduction to Single-Case Experimental Designs for Applied Human Factors and Ergonomics

Abstract

Experimental designs help human factors and ergonomics (HFE) scientists and professionals make decisions about the causal effects of interventions on measures of human cognition, emotion, and performance. HFE researchers have typically used traditional between-subjects, within-subjects, and mixed experimental designs to do so. Although these designs will continue to play an important role in HFE research, some research questions and applied problems do not easily lend themselves to the use of these designs. This is particularly true when a study focuses on the performance of single individuals or two or more individuals performing as a single unit, and/or researchers find it difficult or impossible to obtain enough individuals from the population of interest to achieve sufficient statistical power for traditional experimental designs. In these situations, single-case experimental designs (SCEDs), can offer effective and flexible alternatives to traditional experimental designs. In this paper, we describe the general characteristics of SCEDs and the two most common designs, withdrawal and multiple-baseline designs using HFE examples. SCEDs have demonstrated potential to identify effective interventions for individuals in a variety of domains and contexts relevant to HFE.

Keywords: Single-Case Experimental Designs, Withdrawal Designs, Multiple-Baseline Designs

DOI: 10.54941/ahfe1004742