[R] Anova - adjusted or sequential sums of squares?

(Ted Harding) Ted.Harding at nessie.mcc.ac.uk
Wed Apr 20 17:54:21 CEST 2005

On 20-Apr-05 michael watson \(IAH-C\) wrote:
> I guess the real problem is this:
> As I have a different number of observations in each of the
> groups, the results *change* depending on which order I
> specify the factors in the model.  This unnerves me. With a
> completely balanced design, this doesn't happen - the results
> are the same no matter which order I specify the factors.  
> It's this reason that I have been given for using the so-called
> type III adjusted sums of squares...

This is inevitable. It's not for nothing that unbalanced "designs"
are called "non-orthogonal".

What are the "E" and "NE" effects corresponding to the
observations plotted at "+" in the following diagram?

  /   +

Best wishes,

E-Mail: (Ted Harding) <Ted.Harding at nessie.mcc.ac.uk>
Fax-to-email: +44 (0)870 094 0861
Date: 20-Apr-05                                       Time: 16:54:21
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