1 Sample Sign Test Tutorial

When to use this tool

Use the Sign Test to compare the median (center) of a continuous population to a specified/historical value. As an example, an improvement team wants to test whether the median time to fill out extended warranty forms exceeds the historical median value.

The 1 Sample Sign Test is based on the binomial distribution and can be used on non-normal data.

The test makes the following assumptions:

The data are continuous numeric.
The units are randomly sampled.

If the data distribution is symmetric, use the 1 Sample Wilcoxon Signed Ranks Test instead.

Using EngineRoom

Click to Download Data File

You must have raw data to run any non-parametric test. Summary data cannot be used with these tests.

Example:

The data for this example consists of the time to fill out 15 randomly chosen extended warranty forms. We want to test, at the 10% level, whether the median time to fill out the forms exceeds 3 minutes.

Steps:

Select the Analyze menu > Non-parametric > Click on the 1 Sample Sign Test
Click on the data file in the data sources panel and drag the Orderfill Time variable onto the Data variable drop zone on the study.
Set up the test as shown, and click Continue: