Adhesive qualities of a lens coating
These data are from two experiments to examine the effect of
formulation changes on the adhesive properties of a eye glass
lens coating. If the coating would not adhere to the lens
surface then the formulation would not be marketable. The first
experiment (adhesion) considered only pH (i.e., one
factor). In this experiemnt three formulations were made (one
at each of three pH levles) and ten samples from each
formulation were tested. The test procedure for measuring
adhesion is known to contain a large amount of test error. In
the second experiment ( adhesion2 the effect of pH (3
levels) and a catalyst (2 levels) were tested. The data
consists of five samples were taken from and tested from each of
the six formulations.
adhesion is a data frame with 30 observations on the
following 2 variables.
adhesiona numeric vector
pHa numeric vector at three distinct levels
adhesion2 is a data frame with 30 observations on the following
3 variables.
cata factor with levels A and B
pHa numeric vector
adhesiona numeric vector
Peter R. Nelson, Marie Coffin and Karen A. F. Copeland (2003), Introductory Statistics for Engineering Experimentation, Elsevier. (Appendix A)
str(adhesion)
xtabs(~ pH, adhesion)
xyplot(adhesion ~ pH, adhesion,
ylab = "Adhesion of a lens coating", xlab = "pH",
type = c("g", "p", "a"))
dotplot(as.factor(pH) ~ adhesion, adhesion, ylab = "pH",
type = c("p","a"), xlab = "Adhesion of a lens coating")
str(adhesion2)
xtabs(~ cat + pH, adhesion2)
dotplot(as.factor(pH) ~ adhesion, adhesion2, groups = cat,
type = c("p","a"), ylab = "pH",
auto.key = list(space = "right", lines = TRUE,
title = "Catalyst"))Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.