At 12:33 25/04/2014, you wrote:
Thank you very much for your reply and the book recommendation, Michael.
Yes, I mean Cohen's d - sorry for the typo :-)
Just to make this sure for me: There is no
possibility to integrate stated Cohens' ds in an
R-Metaanalysis (or a MA at all), if there is no
further information traceable regarding SE or the like?
If there is really no other information like
sample sizes, significance level, value of some
significance test then you would have to impute a
value from somewhere. That would seem a last resort.
I have cc'ed this back to the list, please keep
it on the list so others may benefit and contribute.
best regards,
Verena
On Fri, Apr 25, 2014 at 1:21 PM, Michael Dewey
<<mailto:i...@aghmed.fsnet.co.uk>i...@aghmed.fsnet.co.uk> wrote:
At 13:15 24/04/2014, Verena Weinbir wrote:
Hello!
I am using the metafor package for my master's thesis as an R-newbie. While
calculating effectsizes from my dataset (mean values and
standarddeviations) using "escalc" shouldn't be a problem (I hope ;-)), I
wonder how I could at this point integrate additional studies, which only
state conhens d (no information about mean value and sds available), to
calculate an overall analysis. Â I would be very grateful for your support!
You mean Cohen's d I think.
You will need some more information to enable
you to calculate its standard error. Have a look at Rosenthal's chapter in
@book{cooper94,
  author = {Cooper, H and Hedges, L V},
  title = {A handbook of research synthesis},
  year = {1994},
  publisher = {Russell Sage},
  address = {New York},
  keywords = {meta-analysis}
}
(There is an updated edition)
This gives you more information about converting
effect sizes and extracting them from unpromising beginnings.
It often requires some ingenuity to get the
information you need so have a go and then get
back here with more details if you run into problems
Best regards,
Verena
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Michael Dewey
<mailto:i...@aghmed.fsnet.co.uk>i...@aghmed.fsnet.co.uk
http://www.aghmed.fsnet.co.uk/home.html
Michael Dewey
i...@aghmed.fsnet.co.uk
http://www.aghmed.fsnet.co.uk/home.html
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