[R] kruskalmc, significant differences while median values are the same

[Omphalodes Verna]

Dear list!

I work with multiple Kruskal-Wallis test (kruskalmc, package pgirmess), which evaluates differences in medians among groups (5 groups). A result of a test is significant differences among some groups, while median values are the same for 4 groups (using tapply). Why?

p.s.: number of samples in groups vary from 50 to 4900.

Thanks to all, OV

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