Metafor "SMCR" Pre-Post Effect sizes

Absolutely correct. The documentation wasn't clear on that. Changed for the next version of the package. And the escalc() function now no longer checks for sd2i, since it is not needed anyway (for "SMCR"). For now, you will just have to set sd2i to something (e.g., 0).

Thanks for bringing this to my attention!

Best,
Wolfgang

--   
Wolfgang Viechtbauer, Ph.D., Statistician   
Department of Psychiatry and Psychology   
School for Mental Health and Neuroscience   
Faculty of Health, Medicine, and Life Sciences   
Maastricht University, P.O. Box 616 (VIJV1)   
6200 MD Maastricht, The Netherlands   
+31 (43) 388-4170 | http://www.wvbauer.com

-----Original Message-----
From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org]
On Behalf Of Markus K?sters
Sent: Saturday, March 02, 2013 23:31
To: R-help at r-project.org
Subject: [R] Metafor "SMCR" Pre-Post Effect sizes

Dear all,

I am very grateful that Wolfgang Viechtbauer implemented the standardised
mean change for dependent
groups. I was playing around a bit today, and I am not sure if I
understand the "SMCR" procedure correctly. The documentation states that
sd1i and sd2i are needed, but it seems to me that SMCR is ignoring sd2i
(so Variances are not pooled). Instead, it uses sd1i (pre-test sd), as
suggested by Becker 1988. Is that correct?

Thank you all very much for your time and help,

Markus

	[[alternative HTML version deleted]]

______________________________________________
R-help at r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-
guide.html
and provide commented, minimal, self-contained, reproducible code.

Dear Wolfgang,

Thank you for your clarification - and your excellent package !

Best wishes,

Markus

-----Urspr?ngliche Nachricht-----
Von: Viechtbauer Wolfgang (STAT)
[mailto:wolfgang.viechtbauer at maastrichtuniversity.nl] 
Gesendet: Montag, 4. M?rz 2013 10:45
An: Markus K?sters; R-help at r-project.org
Betreff: RE: [R] Metafor "SMCR" Pre-Post Effect sizes

Absolutely correct. The documentation wasn't clear on that. Changed for the
next version of the package. And the escalc() function now no longer checks
for sd2i, since it is not needed anyway (for "SMCR"). For now, you will just
have to set sd2i to something (e.g., 0).

Thanks for bringing this to my attention!

Best,
Wolfgang

--   
Wolfgang Viechtbauer, Ph.D., Statistician   
Department of Psychiatry and Psychology   
School for Mental Health and Neuroscience   
Faculty of Health, Medicine, and Life Sciences   
Maastricht University, P.O. Box 616 (VIJV1)   
6200 MD Maastricht, The Netherlands   
+31 (43) 388-4170 | http://www.wvbauer.com

-----Original Message-----
From: r-help-bounces at r-project.org 
[mailto:r-help-bounces at r-project.org]
On Behalf Of Markus K?sters
Sent: Saturday, March 02, 2013 23:31
To: R-help at r-project.org
Subject: [R] Metafor "SMCR" Pre-Post Effect sizes

Dear all,

I am very grateful that Wolfgang Viechtbauer implemented the 
standardised mean change for dependent groups. I was playing around a 
bit today, and I am not sure if I understand the "SMCR" procedure 
correctly. The documentation states that sd1i and sd2i are needed, but 
it seems to me that SMCR is ignoring sd2i (so Variances are not 
pooled). Instead, it uses sd1i (pre-test sd), as suggested by Becker 
1988. Is that correct?

Thank you all very much for your time and help,

Markus

	[[alternative HTML version deleted]]

______________________________________________
R-help at r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting- 
guide.html and provide commented, minimal, self-contained, 
reproducible code.