shoe {SMPracticals}

Shoe Wear Data

Description

Amount of wear in a paired comparison of two materials used for soling the shoes of 10 boys. The materials were allocated randomly to the left and right feet.

Usage

data(shoe)

Format

A data frame with 20 observations on the following 4 variables.

material

factor giving the shoe sole material

boy

factor with 10 levels

foot

factor giving left or right foot

y

amount of shoe wear

Source

Box, G. E. P., Hunter, W. G. and Hunter, J. S. (1978) Statistics for Experimenters. New York: Wiley. Page 100.

References

Davison, A. C. (2003) Statistical Models. Cambridge University Press. Page 422.

Examples

data(shoe)
attach(shoe)
d <- y[material=="B"]-y[material=="A"]  # difference
t.test(d)  # t test of hypothesis that B wears quicker