Data analysis in single case experimental design studies

For decades, single case experimental designs (SCED) have been used to examine the effectiveness of clinical and educational interventions and have contributed significantly to the development of the general lines of clinical and educational researches. In recent years, with the movement of evidence-based methods, the methodology of single case experimental designs has also evolved. Visual analysis of graphic displays of data is a cornerstone of studies using a single case experimental design. Data are graphed for each participant during a study. In Visual analysis, trend, level, and stability of data assessed and compare within (base line, intervention and follow up) and between conditions of intervention. The purpose of this paper is to provide readers with a rationale for visual analysis of data when using a SCED, a step-by-step guide for conducting a visual analysis of graphed data, as well as to highlight considerations for persons interested in using visual analysis to evaluate an intervention.