snails {GAD}

Growth rates of snails on large boulders on different rock shores

Description

This design was extracted from Underwood (1997), but data are artificial. Snails were transplanted from origin to different shores. Several boulders were used on each shore. Cages with snails of each origin on each boulder were replicated. All factors (origin, shore, boulder and cage) are random.

Usage

data(snails)

Format

A data frame with 240 rows and 6 variables

Details

• origin: a random factor with two levels (O1, O2)

• shore: a random factor with four levels (S1, S2, S3, S4) orthogonal to origin

• boulder: a random factor with three levels (B1, B2, B3) nested in shore

• cage: a random factor with two levels (C1, C2) nested in the combination of boulder and origin

• replicate: sample size

• growth: response variable

References

Underwood, A.J. 1997. Experiments in Ecology: Their Logical Design and Interpretation Using Analysis of Variance. Cambridge University Press, Cambridge.

Examples

library(GAD)
data(snails)
snails