This data file is intended for use with the Split-Plot Factorial tutorial.
A manufacturer wants to determine the effect of three methods of pulp preparation and four levels of cooking temperature on the tensile strength of paper. These twelve combinations can be conducted in one day.
To increase statistical power, the paper chemist decides to perform three replicates of this twelve-run general factorial design over three days, which produces a total of 36 runs. However, it is not feasible to perform the experiment in a random fashion. Instead, on each of the three days, this experimenter produces a batch of pulp and divides it into four samples to be cooked at four different temperatures. The process is repeated for pulp prepared by the two other methods.
35
45
35
84
84
84
a2
250
38
a2
275
42
a2
225
41
a2
200
34
a1
250
37
a1
275
36
a1
225
35
a1
200
30
a3
275
36
a3
200
29
a3
225
26
a3
250
33
a2
275
40
a2
225
36
a2
250
42
a2
200
31
a1
225
32
a1
275
41
a1
200
28
a1
250
40
a3
225
30
a3
250
32
a3
200
31
a3
275
40
a1
275
40
a1
250
41
a1
200
31
a1
225
37
a2
275
44
a2
225
40
a2
250
39
a2
200
35
a3
275
45
a3
250
39
a3
200
32
a3
225
34