[R] Metafor: How to integrate effectsizes?

[Michael Dewey]

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.  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
>
>         [[alternative HTML version deleted]]

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