Signed rank sum test (one sample)
The Signed rank sum test is a test for symmetry about a test value. This test is the non-parametric alternative for the One sample t-test. It can be used when the observations are not Normally distributed.
- Select the variable of interest.
- Optionally select a filter to include a subset of cases.
- Test value: the value you want to compare the sample data with.
The Signed rank sum test ranks the absolute values of the differences between the sample data and the test value, and calculates a statistic on the number of negative and positive differences. If the resulting P-value is small (P<0.05), then the sample data are not symmetrical about the test value and therefore a statistically significant difference can be accepted between the sample median and the test value.
- Altman DG (1991) Practical statistics for medical research. London: Chapman and Hall.
- Mann-Whitney test (independent samples)
- Wilcoxon test (paired samples)
- More help on variables
- More help on filters