The
guayule
data frame, a design object, has 96 rows and 5 columns.
The guayule
is a Mexican plant from which rubber is manufactured.
Batches of 100 seeds of eight varieties (
variety
) of guayule were
given one of four treatments (
treatment
), and planted; the number of
plants that came up in each batch (
plants
) was recorded.
In order to separate the effect of which
flat (planting tray) a batch was planted on from the effect of the treatment,
each flat was planted with seeds from
only one variety, but all the treatments were represented in each flat.
This data frame contains the following columns:
rep
.
Federer, W.T. (1955) Experimental Design Theory and Applications.
The Macmillan Company, New York.
John M. Chambers and Trevor J. Hastie, (eds.) Statistical Models in S,
Wadsworth and Brooks, Pacific Grove, CA 1992, pg. 157.
gaov <- aov(plants ~ variety * treatment + Error(flats))