The data gives the proportion of leaf area affected by leaf blotch on 10 varieties of barley at 9 different sites.
data(leafblotch)A data frame with 90 observations on the following 3 variables.
blotchproportion of the barley leaf affected by blotch
sitethe physical location - a factor with levels 1 2 3 4 5 6 7 8 9
varietyvariety of barley - a factor with levels 1 2 3 4 5 6 7 8 9 10
P. McCullagh and J. Nelder (1989) "Generalized Linear Models" Chapman and Hall, 2nd ed.