Posted by
Mike on
May 01, 2011; 1:55am
URL: http://spssx-discussion.165.s1.nabble.com/Winsorizing-in-meta-analysis-tp4361802p4362155.html
I'm in a situation similar to that of Bruce. I focused on meta-analysis
methods about a decade ago and was surprized to hear about the
use of Winsorization. A quick Google search (also of scholar.google.com)
in fact turns up a number of references which refer to the use of
trimmed means and winsorized variances/standard deviation. One
article that might be of relevance is the following:
Keselman, H. J.; Algina, James; Lix, Lisa M.; Wilcox, Rand R.; Deering,
Kathleen N. (2008). A generally robust approach for testing hypotheses
and setting confidence intervals for effect sizes. Psychological Methods,
Vol 13(2), Jun 2008, 110-129.
doi: 10.1037/1082-989X.13.2.110
Keselman & Co argue for the use of robust effect size measures and
propose on based on trimmed means and winsorized variances/SD.
Their Table 4 on page 117 provides a listing of the different effect
size measures that have suggested as well as their own for independent
groups and correlated groups designs.
Keselman & Co have several articles on this topic searching
scholar.google.com and/or PsycInfo will turn them up as well as articles
that cite them.
-Mike Palij
New York University
[hidden email]
----- Original Message -----
From: "Bruce Weaver" <
[hidden email]>
To: <
[hidden email]>
Sent: Saturday, April 30, 2011 8:37 PM
Subject: Re: Winsorizing in meta-analysis
> Hi Art. Several years ago, I worked for a group that did a lot of
> meta-analysis, and Winsorizing was never part of their procedure. But as I
> say, that was several years ago. However, I've just searched the Cochrane
> Handbook (
http://www.cochrane-handbook.org/) for "Winsorize" (and
> "Winsorise"), and found no mention of it there either.
>
> Just to be clear, is your colleague suggesting Winsorization of the point
> estimates from the various studies before computation of the pooled
> estimate? Are they computing a fixed or random effects estimate? Do they
> have a priori hypotheses about possible heterogeneity of the point
> estimates?
>
> HTH.
>
> Cheers,
> Bruce
>
>
>
> Art Kendall wrote:
>>
>> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01
>> Transitional//EN">
>>
>>
>> I am not near my books right now, so I would like to
>> get feedback from the list.
>>
>> A colleague was saying that she took a course a few weeks ago, and
>> the prof said that winsorizing usually should be done in
>> meta-analysis. I found this surprising but she was adamant.
>>
>> In general, over analyses in general I have found that a
>> subjective 80% of anomalous values are data entry errors. I have
>> grudgingly trimmed or winsorized only when the value of a
>> variable is substantively implausible?
>>
>> What is your experience?
>>
>> Is routinely winsorizing in meta-analysis what you teach?
>>
>> If you do winsorize in meta-analysis, how often do you do it? How
>> do you decide when to do it?
>>
>> Is this the current practice?
>>
>>
>> Art Kendall
>> Social Research Consultants
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> =====================
>> To manage your subscription to SPSSX-L, send a message to
>>
[hidden email] (not to SPSSX-L), with no body text except the
>> command. To leave the list, send the command
>> SIGNOFF SPSSX-L
>> For a list of commands to manage subscriptions, send the command
>> INFO REFCARD
>>
>
> -------
> Bruce Weaver
>
[hidden email]
>
http://sites.google.com/a/lakeheadu.ca/bweaver/>
> "When all else fails, RTFM."
>
> NOTE: My Hotmail account is not monitored regularly.
> To send me an e-mail, please use the address shown above.
> --
> View this message in context:
http://spssx-discussion.1045642.n5.nabble.com/Winsorizing-in-meta-analysis-tp4361802p4362030.html> Sent from the SPSSX Discussion mailing list archive at Nabble.com.
>
> =====================
> To manage your subscription to SPSSX-L, send a message to
>
[hidden email] (not to SPSSX-L), with no body text except the
> command. To leave the list, send the command
> SIGNOFF SPSSX-L
> For a list of commands to manage subscriptions, send the command
> INFO REFCARD
=====================
To manage your subscription to SPSSX-L, send a message to
[hidden email] (not to SPSSX-L), with no body text except the
command. To leave the list, send the command
SIGNOFF SPSSX-L
For a list of commands to manage subscriptions, send the command
INFO REFCARD