Analysis of Variance
In order to take account of interactions, the AIAG manual
recommends the use of ANOVA. Mesa
also generates a fully linked ANOVA worksheet and the output for the AIAG data
is shown below (the AIAG version is shown on page 74 of the 2^{nd}
edition):
Note that Mesa signifies whether or not a particular
effect is significant. We can see
that the AIAG data exhibits a statistically significant interaction effect.
The Wheeler & Lyday approach regards this as a problem which should
be eliminated, rather than a parameter which should be estimated.
The ANOVA worksheet in Mesa is fully linked to the values
on the Raw Data sheet and therefore updates automatically.
