Description

Comparison of eyeglass ultra-violet coatings

Format

A data frame with 10 observations on the following 3 variables.

a

a numeric vector of differences in haze values for the commercial coating

b

a numeric vector of differences in haze values for the commercial coating

diff

a numeric vector of the differences in the two above vectors

Details

A field test of a new coating was conducted with 10 volunteers who wore glasses on a regular basis. Each subject had one lens coated with a commercial product and one lens coated with a test product. The coatings were applied to the lens in a random fashion such that some subjects had the commercial coating on their right lens and some on their left lens. The haze of each lens was measured at the beginning and the end of the study with the difference in haze being the measure of interest.

References

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

Examples