multcomp (version 0.3-8)

detergent: Detergent Durability Data Set

Description

Detergent durability in a fractional design experiment; data set taken from Westfall et al. (1999, p. 189). Balanced incomplete block design.

Usage

data(detergent)

source

P. H. Westfall, R. D. Tobias, D. Rom, R. D. Wolfinger, Y. Hochberg (1999). Multiple Comparisons and Multiple Tests Using the SAS System. Cary, NC: SAS Institute Inc.

Details

See Westfall et al. (1999, p. 189)

Examples

data(detergent)

N <- rep(2, 5)

# BIBD: prepare the contrast matrix = all-pair comparisons for 
# the 5 levels of detergent

C <- contrMat(N, type="Tukey")

# adjusted p-values: either using the contrast matrix C
summary(simtest(plates ~ block+detergent, data=detergent, whichf="detergent",
                ttype="logical", cmatrix=C))

# or, more easily, type="Tukey"
summary(simtest(plates ~ detergent + block, data=detergent,
        whichf="detergent", type="Tukey", ttype="logical"))