Validation of the Use of a Nonparametric Smoother for the Examination of Data from a Single-Subject Design

Abstract

The statistical analysis of data from a single-subject design remains somewhat an issue of debate. The frequently employed procedure for examining data from a single-subject design involves visually inspecting the graphed outcome variable over the observation time. Potential difficulties of this procedure have been shown. The application of traditional statistical tests has also been questioned. The nonparametric smoother has been presented as a possibly appropriate and useful technique for the examination of data from a single-subject research paradigm. This article attempts to validate the use of a nonparametric smoother for the examination of data from a single-subject design. A recommendation is given regarding the use of this technique.

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