[R] clustered data in wilcox_test
Devin M. Caughey
devin.caughey at gmail.com
Tue Oct 12 07:48:21 CEST 2010
Dear all,
I have R code of the following form:
wilcox_test(categoricalResponse ~ binaryTreatment | matchedCluster)
The data consist of 11 matched pairs of clusters, each of which contains a variable number of units on which the response variable is measured. Treatment, however, was assigned at the level of the cluster. First, is there any way to make `wilcox_test' calculate p-value based on the permutation distribution of the _clusters_, rather than treating all units in each stratum as independent? Second, does the function `wilcox_test' (and similar functions like `surv_test') in the `coin' package weights the linear statistic in each stratum by 1/(N_s + 1), where N_s is the number of observations in the stratum, as is suggested by van Elteren (1960)?
Thank you for your assistance.
Devin
---
Devin M. Caughey
PhD Candidate, Political Science
IGERT-PEPPP Fellow
UC Berkeley, 210 Barrows Hall, Berkeley, CA 94720-1950
caughey at berkeley.edu
www.devincaughey.com
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