output of kruskal()

stephane champely (champely@stid.iut.univ-metz.fr)
Thu, 22 Jan 1998 07:40:17 +0100


Hi,
just one remark about the output and the help file of the kruskal function
(not the computation) for performing kruskal-wallis' test.
The alternative hypothesis is ONE SIDED p=P(chi-squared(k-1)>KWobs) and the
computation are indeed one sided not TWO SIDED.

> books
[1] 93 98 216 249 301 319 731 910 29 39 60 78 82 112 125 170 192 224 263
[20] 275 276 286 369 756 126 142 156 228 245 246 370 419 433 454 478 503
> books.fact
[1] 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3

> kruskal.test(books,books.fact)

Kruskal-Wallis rank sum test

data: books and books.fact
Kruskal-Wallis chi-square = 4.9071, df = 2, p-value = 0.086
alternative hypothesis: two.sided

> 1-pchisq(4.9071,2)
[1] 0.08598779
>

*********************************
Stephane CHAMPELY
Statistique et Traitement Informatique des Donnees
I.U.T. de Metz
Ile du Saulcy
57045 METZ cedex 1
tel: 03 87 31 51 62
fax: 87 31 51 55
E mail: champely@stid.iut.univ-metz.fr
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