curl dataset

Curl of transparencies

The current formulation of a coating on transparencies used in ink-jet printers causes them to curl. These data are from experiments conducted on a new formulation of the coating to reduce the amount of curl. 1.1

data

Format

A data frame with 12 observations on the following 3 variables.

• catalyst: amount of catalyst
• compa: amount of component a (the second component)
• curl: a measure of the curl

Details

These data were collected when transparencies were still widely used for presentations. With the proliferation of projectors, transparencies are being used less and less. However, coatings on paper will continue to be an area of research as coatings have to interact with a variety of printers and inks in order to be useful.

References

Peter R. Nelson, Marie Coffin and Karen A. F. Copeland (2003), Introductory Statistics for Engineering Experimentation, Elsevier. (Appendix A)

Examples

str(curl)
xtabs(~ catalyst + compa, curl)   ## display the experimental design
xyplot(curl ~ compa | ordered(catalyst), curl,
       type = c("g","p","r"), layout = c(3,1),
       xlab = "Amount of component `a' - panels are amount of catalyst",
       ylab = "Amount of curl")