Yes, exactly. After all if you show two things are different you
cannot say they are the same.
Michael
On 03/05/2021 15:59, Gladys Barragan-Jason wrote:
Okay, so you can't obtain an overall effect size while controlling
for design?
Le lun. 3 mai 2021 ? 14:36, Michael Dewey <lists at dewey.myzen.co.uk
<mailto:lists at dewey.myzen.co.uk>> a ?crit?:
??? If you include a moderator you do not get an overall effect
because by
??? including it you are effectively saying there is no single overall
??? effect.
??? On 03/05/2021 12:24, Gladys Barragan-Jason wrote:
???? > Hi Michael,
???? > Thanks a lot for your quick response. Here are answers and other
???? > questions below.
???? >
???? > Le?lun. 3 mai 2021 ??12:41, Michael Dewey
??? <lists at dewey.myzen.co.uk <mailto:lists at dewey.myzen.co.uk>
???? > <mailto:lists at dewey.myzen.co.uk
??? <mailto:lists at dewey.myzen.co.uk>>> a ?crit?:
???? >
???? >? ? ?Dear Gladys
???? >
???? >? ? ?Comments in-line
???? >
???? >? ? ?On 03/05/2021 08:13, Gladys Barragan-Jason wrote:
???? >? ? ? > Dear all,
???? >? ? ? >
???? >? ? ? > I am doing a meta-analysis on experimental data on the
??? impact on
???? >? ? ? > several?behavioral interventions including both *pre-post
??? studies*
???? >? ? ? > (measurement of a trait before and after the intervention)
??? *and
???? >? ? ?control
???? >? ? ? > vs. treatment studies *(measurement?after a control
??? intervention vs.
???? >? ? ? > measurement after the intervention).
???? >
???? >? ? ?So the first design just has one group which is measured
??? twice and the
???? >? ? ?second design has two parallel groups which are each measured
??? once?
???? >
???? >
???? > Exactly!
???? >
???? >
???? >? ? ? > I am interested in the effect size of each type of
??? intervention on a
???? >? ? ? > specific trait that is common to all studies.
???? >? ? ? >
???? >? ? ? > I would like to know whether?it is correct to compile all
??? studies
???? >? ? ?from
???? >? ? ? > one type of intervention (whatever?the type of
comparisons:
???? >? ? ?pre-pot and
???? >? ? ? > control vs. treatment group together) with pre- and
??? control being as
???? >? ? ? > control and post and treatment being as treatment.
???? >? ? ? >
???? >
???? >? ? ?I do not think that is going to work well. Although the two
??? designs
???? >? ? ?could be considered as estimating the same effect their
??? variability
???? >? ? ?should be very different since in design 1 you have reduced
??? the effect
???? >? ? ?of individual variability. If you do include both designs
in one
???? >? ? ?analysis I would have thought it mandatory to include a
??? moderator with
???? >? ? ?two levels for design.
???? >
???? > This makes sense. When I do this, I then obtain two effect sizes
??? (one
???? > for each design); (in having mods=~design-1). Do you know how I
??? can get
???? > the overall effect size?
???? >
???? >
???? >? ? ? > I have a second question about how to thank the
???? >? ? ? > r-sig-meta-analysis at r-project.org
??? <mailto:r-sig-meta-analysis at r-project.org>
???? >? ? ?<mailto:r-sig-meta-analysis at r-project.org
??? <mailto:r-sig-meta-analysis at r-project.org>>
???? >? ? ? > <mailto:r-sig-meta-analysis at r-project.org
??? <mailto:r-sig-meta-analysis at r-project.org>
???? >? ? ?<mailto:r-sig-meta-analysis at r-project.org
??? <mailto:r-sig-meta-analysis at r-project.org>>> list for all their help
???? >? ? ? > (acknowledgements?in a paper).
???? >
???? >? ? ?I would have thought the URL
???? > https://stat.ethz.ch/mailman/listinfo/r-sig-meta-analysis//
<https://stat.ethz.ch/mailman/listinfo/r-sig-meta-analysis//>
???? > ?<https://stat.ethz.ch/mailman/listinfo/r-sig-meta-analysis//
<https://stat.ethz.ch/mailman/listinfo/r-sig-meta-analysis//>>
???? >? ? ?was better. How to do this will also depend on custom and
??? practice in
???? >? ? ?your scientific discipline, some journals in mine require
??? people who
???? >? ? ?are
???? >? ? ?acknowledged to give their consent.
???? >
???? >
???? > Ok! Thanks a lot!
???? >
???? > Best,
???? > Gladys
???? >
???? >
???? >? ? ?Michael
???? >
???? >? ? ? >
???? >? ? ? > Thanks a lot for your help!
???? >? ? ? >
???? >? ? ? > Have a great day,
???? >? ? ? >
???? >? ? ? > Gladys
???? >? ? ? >
???? >? ? ? > --
???? >? ? ? >
???? >? ? ? > ------------------------------------------
???? >? ? ? >
???? >? ? ? > Gladys Barragan-Jason, PhD. ____?Website
???? >? ? ? > <https://sites.google.com/view/gladysbarraganjason/home
<https://sites.google.com/view/gladysbarraganjason/home>
???? > ?<https://sites.google.com/view/gladysbarraganjason/home
<https://sites.google.com/view/gladysbarraganjason/home>>>
???? >? ? ? >
???? >? ? ? > Station d'Ecologie Th?orique et Exp?rimentale (SETE)____
???? >? ? ? >
???? >? ? ? > CNRS de Moulis____
???? >? ? ? >
???? >? ? ? > image.pngimage.png____
???? >? ? ? >
???? >? ? ? >
???? >? ? ? >
???? >? ? ? >
???? >? ? ? >
???? >
?<http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient
<http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient>
???? >
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<http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient>>>
???? >
???? >? ? ? >? ? ? ?Virus-free. www.avg.com <http://www.avg.com>
??? <http://www.avg.com <http://www.avg.com>>
???? >? ? ? >
???? >
?<http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient
<http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient>
???? >
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<http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient>>>
???? >
???? >? ? ? >
???? >? ? ? >
???? >? ? ? > <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
???? >? ? ? >
???? >? ? ? > _______________________________________________
???? >? ? ? > R-sig-meta-analysis mailing list
???? >? ? ? > R-sig-meta-analysis at r-project.org
??? <mailto:R-sig-meta-analysis at r-project.org>
???? >? ? ?<mailto:R-sig-meta-analysis at r-project.org
??? <mailto:R-sig-meta-analysis at r-project.org>>
???? >? ? ? > https://stat.ethz.ch/mailman/listinfo/r-sig-meta-analysis
<https://stat.ethz.ch/mailman/listinfo/r-sig-meta-analysis>
???? > ?<https://stat.ethz.ch/mailman/listinfo/r-sig-meta-analysis
<https://stat.ethz.ch/mailman/listinfo/r-sig-meta-analysis>>
???? >? ? ? >
???? >
???? >? ? ?--
???? >? ? ?Michael
???? > http://www.dewey.myzen.co.uk/home.html
??? <http://www.dewey.myzen.co.uk/home.html>
???? >? ? ?<http://www.dewey.myzen.co.uk/home.html
??? <http://www.dewey.myzen.co.uk/home.html>>
???? >
???? >
???? >
???? > --
???? >
???? > ------------------------------------------
???? >
???? > Gladys Barragan-Jason, PhD. ____?Website
???? > <https://sites.google.com/view/gladysbarraganjason/home
<https://sites.google.com/view/gladysbarraganjason/home>>
???? >
???? > Station d'Ecologie Th?orique et Exp?rimentale (SETE)____
???? >
???? > CNRS de Moulis____
???? >
???? > image.pngimage.png____
???? >
???? >
???? >
??? -- ??? Michael
??? http://www.dewey.myzen.co.uk/home.html
??? <http://www.dewey.myzen.co.uk/home.html>