Can anyone help me understand the following error message in SPSS 26 Kruskal-Wallis test:

"Unable to compute. All test field values are less than or equal to the median."

Many thanks!
#SPSSStatistics

Hi Iris,

There are two procedures that produce Kruskal-Wallis tests, NPTESTS, and the older NPAR TESTS. The K-W test would be obtained in NPTESTS in the menus via Analyze>Nonparametric Tests>Independent Samples, while NPAR TESTS would be obtained via Analyze>Nonparametric Tests>Legacy Dialogs>K Independent Samples. Can you clarify which procedure was used?

In order for all values to be at or below the median, I would think the dependent variable would have to be a constant. However, when I try using a constant dependent in both procedures, I don't get an error, just a test statistic value of 0 and a significance/p value of 1. Can you share more information about the data involved?

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David Nichols
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