Use 1-Sample Sign
to estimate the population median and to compare it to a target value or a reference value. Using this test, you can do the following:
- Determine whether the population median differs from the hypothesized median that you specify.
- Calculate a range of values that is likely to include the population median.
For example, a consultant for a large company uses a 1-sample sign test to determine whether the company's median salary differs from the industry average of $45,000. If the median differs from the target, the analyst uses the confidence interval to determine how large the difference is likely to be and whether that difference has practical significance.
The 1-sample sign test does not make assumptions about population symmetry.
Where to find this analysis
When to use an alternate analysis
If your data come from a symmetric distribution, use a 1-Sample Wilcoxon.
If you have more than 20 observations, or if your data aren't severely skewed, use a 1-Sample t because the test has more power.