The Runs Test procedure tests whether the order of occurrence of two values of a variable is random. A run is a sequence of like observations. A sample with too many or too few runs suggests that the sample is not random.
Examples. Suppose that 20 people are polled to find out whether they would purchase a product. The assumed randomness of the sample would be seriously questioned if all 20 people were of the same gender. The runs test can be used to determine whether the sample was drawn at random.
Statistics. Mean, standard deviation, minimum, maximum, number of nonmissing cases, and quartiles.
Runs Test Data Considerations
Data. The variables must be numeric. To convert string variables to numeric variables, use the Automatic Recode procedure, which is available on the Transform menu.
Assumptions. Nonparametric tests do not require assumptions about the shape of the underlying distribution. Use samples from continuous probability distributions.
To Obtain a Runs Test
This feature requires the Statistics Base option.
- From the menus choose:
- Select one or more numeric test variables.
- Optionally, click Options for descriptive statistics, quartiles, and control of the treatment of missing data.
This procedure pastes NPAR TESTS command syntax.