This macro performs Tukey's 1 degree of freedom test of nonadditivity, which is a test for an interaction in a two-factor experiment with a single replicate.
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Three columns containing the results from a two-factor experiment with a single replicate
Suppose you have the following results of such a two-factor experiment in C1-C3 of the worksheet:
C1 | C2 | C3 |
---|---|---|
Temp | Pressure | Y |
40 | 20 | 7.9 |
40 | 25 | 11.3 |
40 | 30 | 13.5 |
50 | 20 | 12.7 |
50 | 25 | 10.9 |
50 | 30 | 10.2 |
60 | 20 | 11.3 |
60 | 25 | 10.8 |
60 | 30 | 11.0 |
To run the macro, choose and type:
%TUK1DF C3 C1 C2
Click Run.
The output includes the sum of squares for both nonadditivity and error, the significance level, the test statistic, the critical value, and the conclusion.
"The test partitions the residual sum of squares into a single-degree-of-freedom component due to nonadditivity (interaction) and a component for error..."
Douglas C. Montgomery, Design and Analysis of Experiments, 5th Ed, 2001, pp 191-194.