statistics.compare: the chosen test had too ...

Warnings reference › compare:degenerate

Identifier

compare:degenerate

Raised by

The grid (core)

Since

1.106.0

What happened

The test ran and could not produce a statistic: too few values, or no variation at all within them. null is returned rather than a p-value computed from a degenerate sample.

The fix

Compare groups with more rows, or check that the measure actually varies within them.

Reference

Covered in full at the API reference.