[SciPy-User] stats repeated measures ANOVA

[josef.pktd at gmail.com]

On Mon, Apr 11, 2011 at 10:52 PM, Peter <ptittmann at gmail.com> wrote:
> All,
>
> I would like to determine the effect of  two independent variables (tree
> size class, and canopy percent cover) which are factor vectors
> (non-continuous) on the variance between two methods of measuring tree
> height.
>
> I believe this is referred to as two-way repeated measures ANOVA.

As far as I understand ANOVA only tests for differences in means, or
mean effects, not differences in variances, equality of variances is
usually a standard assumption for ANOVA.

But it's not clear to me what you want to test or estimate, with size,
cover and method you have actually 3 factors.
Are the two measuring methods for height used for every tree?
Do you want the effect of size and cover on the measurement variance
for each method separately?
....?

I don't know much about two-way repeated measures ANOVA directly, but
my guess is that it can be translated into estimating with a linear
model and doing some heteroscedasticity tests on it.
statsmodels might have the basis for this, but without more details on
what exactly you want to estimate or test it's difficult to tell how
much work this is.

Cheers,

Josef



>
> Can anyone refer me to existing scipy (or other) methods for conducting
> this type of analysis?
>
> Best,
> Peter
>
>
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