exactRankTests (version 0.7-7)

rotarod: Rotating Rats Data

Description

The endurance time of 24 rats in two groups in a rotating cylinder.

Usage

data(rotarod)

source

R. Bergmann, J. Ludbrook and W. P.J.M. Spooren (2000). Different outcomes of the Wilcoxon-Mann-Whitney test from different statistics packages. The American Statistician, 54(1), 72--77.

Details

The rats were randomly assigned to the control and treatment group. The treatment group received an oral dose of a centrally ating muscle relaxant and the control group a saline solvent. This dataset serves as the basis of an comparision of the results of the Wilcoxon-Mann-Whitney test computed by 11 statistical packages in Bergmann et al. (2000). The exact conditional p-value is $0.0373$ (two-sided) and $0.0186$ (one-sided). The asymptotic two-sided p-value (corrected for ties) is reported as $0.0147$.

Examples

data(rotarod)
wilcox.exact(time ~ group, data=rotarod, alternative="g")
wilcox.exact(time ~ group, data=rotarod, conf.int=TRUE)
wilcox.exact(time ~ group, data=rotarod, exact=FALSE)
# the permutation test
perm.test(time ~ group, data=rotarod)
perm.test(time ~ group, data=rotarod, exact=FALSE)