17.5.3 Paired-Sample Sign Test


The paired-sample sign test is a non-parametric alternative to the paired-sample t-test. It is frequently used to test the effect of a treatment on a group of subjects. The data must be paired measurements (for example, "before" and "after" data resulting from a clinical trial).

Unlike the paired-sample t-test, the paired-sample sign test does not require the assumption of normality. Thus, when normality is questionable, the paired-sample sign test can be used in place of the paired-sample t-test.

Handling Missing Values

If there are missing values in the data range, the whole pair will be excluded in the analysis

Performing Paired-Sample Sign Test

To perform a paired-sample sign test:

  1. Select Statistics: Nonparametric Tests: Paired-Sample Sign Test. This opens the sign2 dialog box.
  2. Specify the Data Range, and the Alternate Hypothesis.
  3. Upon clicking OK, an analysis report sheet is generated showing the frequency table, degrees of freedom, the S and Z statistics, the associated p-value, and the test conclusion.

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