Here the experiment is set up
A <- c(1,2)
B <- c(1,1,2,2,3,3)
Spindle <- c(rep(A,12))
Machine <- c(rep(B,4))
obs <- c(12, 8 ,14, 12, 14, 16,
9, 9, 15, 10, 10, 15,
11, 10, 13, 11, 12, 15,
12, 8, 14, 13, 11, 14)
Machine <- as.fixed(Machine)
Spindle <- as.random(Spindle)
As a nested effect spindle is set to random. Machine is a fixed effect.
model <- lm(obs ~ Machine + Spindle %in% Machine)
summary(model)
##
## Call:
## lm(formula = obs ~ Machine + Spindle %in% Machine)
##
## Residuals:
## Min 1Q Median 3Q Max
## -2.00 -0.75 0.00 1.00 2.25
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) 11.0000 0.6067 18.132 5.2e-13 ***
## Machine2 3.0000 0.8580 3.497 0.00258 **
## Machine3 0.7500 0.8580 0.874 0.39355
## Machine1:Spindle2 -2.2500 0.8580 -2.622 0.01726 *
## Machine2:Spindle2 -2.5000 0.8580 -2.914 0.00926 **
## Machine3:Spindle2 3.2500 0.8580 3.788 0.00135 **
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 1.213 on 18 degrees of freedom
## Multiple R-squared: 0.7897, Adjusted R-squared: 0.7313
## F-statistic: 13.52 on 5 and 18 DF, p-value: 1.45e-05
From the data analysis spindle 1 on machine 1, has the highest deviation, followed by machine 3 spindle 2.