[R] metafor- interpretation of moderators test for raw proportions

[Michael Dewey]

At 17:03 03/08/2012, cpanderson wrote:
>Wolfgang,
>Thanks for your quick response.  You are correct- indeed I had inadvertently
>left out that i had set intercept = FALSE in rma.

Dear Christopher,
It does help if you paste in the exact code you used, see also below


>Following your suggestions, I get the following results:
>
>Test of Moderators (coefficient(s) 2,3):
>QM(df = 2) = 0.2207, p-val = 0.8955
>
>Model Results:
>
>          estimate      se     zval    pval    ci.lb   ci.ub
>intrcpt    0.6498  0.0492  13.2160  <.0001   0.5534  0.7462  ***
>Complex    0.0457  0.1007   0.4538  0.6500  -0.1517  0.2430
>Dome       0.0244  0.1135   0.2148  0.8299  -0.1980  0.2468
>
>This may be an even dumber question than my first one, but if you have time
>I'd appreciate knowing how this works.  Originally I had tried the syntax
>mods = ~ Technique.  I ended up getting the following error message:
>
>Error in qr.solve(wX, diag(k)) : singular matrix 'a' in solve
>
>if I supply the argument that mods =~ factor(Technique), I don't get the
>singular matrix 'a' message.  But I don't understand why that should make a
>difference, because dat$Technique is already an object of class factor:

Pasting in the exact code would help here and maybe also giving the 
output of traceback(). You might also consider pasting in the result 
of summary(dat) unless it is really huge.

>class(dat$Technique)
>[1] "factor"
>
>Thanks again.
>
>Christopher
>
>
>
>
>
>--
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>Sent from the R help mailing list archive at Nabble.com.

Michael Dewey
info at aghmed.fsnet.co.uk
http://www.aghmed.fsnet.co.uk/home.html