Semiconductor split-plot experiment

Description

The Semiconductor data frame has 48 rows and 5 columns.

Format

This data frame contains the following columns:

resistance

a numeric vector

ET

a factor with levels 1 to 4 representing etch time.

Wafer

a factor with levels 1 to 3

position

a factor with levels 1 to 4

Grp

an ordered factor with levels 1/1 < 1/2 < 1/3 < 2/1 < 2/2 < 2/3 < 3/1 < 3/2 < 3/3 < 4/1 < 4/2 < 4/3

Source

Littel, R. C., Milliken, G. A., Stroup, W. W., and Wolfinger, R. D. (1996), SAS System for Mixed Models, SAS Institute (Data Set 2.2(b)).

Examples

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str(Semiconductor)
if (require("lme4", quietly = TRUE, character = TRUE)) {
  options(contrasts = c(unordered = "contr.SAS", ordered = "contr.poly"))
  print(fm1Semi <- lmer(resistance ~ ET * position + (1|Grp), Semiconductor))
  print(anova(fm1Semi))
  print((fm2Semi <- lmer(resistance ~ ET + position + (1|Grp), Semiconductor)))
  print(anova(fm2Semi))
}