Re: Contrasts

Arthur wrote:
> Dear Jason,
> ............
>
> One approach would be to calculate the predicted Variety:Nitrogen means
> with their variance matrix, and then do a t test of the difference between the
> mean for Marvelous:0.2cwt and Victory:0.2cwt
>
> In this balanced example, this should give the same result but in general,
> the test of a regression coefficient, an an ANOVA statistic may give different results.
>
> I trust this helps explain the principles behind the calculation.

Thanks, Arthur! For the alternative approach using t test, how to calculate the degree of freedom then?

Jason

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Received on Sun Jul 11 2009 - 08:11:19 EST