I think, some other folks are being sloppy about effect sizes.
"Power analysis for the social sciences" is a book that
defines small, medium and large effects in terms that are
convenient and *usually* appropriate
for the *social sciences* -- it makes no pretenses
that these are universally
I remember I read somewhere about different effect size measures
and now I found the spot: A book by Michael Oakes, U. of Sussex,
"Statistical Inference" 1990. The measures were (xbar-ybar)/s,
Proportion misclassified, r squared (biserial corr) and w squared
(which I think means the same as Rs
Mike Granaas wrote:
> I think that we might agree: I would say that studies need a clear a
> priori rational (theoretical or empirical) prior to being conducted. It
> is only in that context that effect sizes can become meaningful. If a
Even then standardized effect sizes may not be very helpf
Dennis Roberts <[EMAIL PROTECTED]> wrote:
: given a simple effect size calculation ... some mean difference compared to
: that is ... can we not get both NS or sig results ... when calculated
: effect sizes are small, medium, or large?
: if that is true ... then what benefit is there to look a
Hi
I found the Rosenthal reference that addresses the following
point:
On 13 Sep 2001, Herman Rubin wrote:
> The effect size is NOT small, or it would not save more
> than a very small number of lives. If it were small,
> considering the dangers of aspirin, it would not be used
> for this purpo
Hi
On 13 Sep 2001, Herman Rubin wrote:
> jim clark <[EMAIL PROTECTED]> wrote:
> >Or consider a study with a small effect size that is significant.
> >The fact that the effect is significant indicates that some
> >non-chance effect is present and it might very well be important
> >theoretically
jim clark wrote:
>
>
> Sometimes I think that people are looking for some "magic
> bullet" in statistics (i.e., significance, effect size,
> whatever) that is going to avoid all of the problems and
> misinterpretations that arise from existing practices. I think
> that is a naive belief and tha
On Thu, 13 Sep 2001, Paul R. Swank wrote in part:
> Dennis said
>
> other than being able to say that the experimental group ... ON AVERAGE ...
> had a mean that was about 1.11 times (control group sd units) larger than
> the control group mean, which is purely DESCRIPTIVE ... what can you say
In article <[EMAIL PROTECTED]>,
jim clark <[EMAIL PROTECTED]> wrote:
>Hi
>On 12 Sep 2001, Dennis Roberts wrote:
>> that is ... can we not get both NS or sig results ... when calculated
>> effect sizes are small, medium, or large?
>> if that is true ... then what benefit is there to look at
>>
In article <[EMAIL PROTECTED]>,
jim clark <[EMAIL PROTECTED]> wrote:
>Hi
>On 13 Sep 2001, Rolf Dalin wrote:
>> Hi, this is about Jim Clark's reply to dennis roberts.
.
>Sometimes I think that people are looking for some "magic
>bullet" in statistics (i.e
Dennis said
other than being able to say that the experimental group ... ON AVERAGE ...
had a mean that was about 1.11 times (control group sd units) larger than
the control group mean, which is purely DESCRIPTIVE ... what can you say
that is important?
However, can you say even that unless it
On Thu, 13 Sep 2001, Dennis Roberts wrote:
> see the article that focuses on this even if they do report effect sizes ... )
>
> what we need in all of this is REPLICATION ... and, the accumulation of
> evidence about the impact of independent variables that we consider to have
> important poten
here are some data ... say we randomly assigned 30 Ss ... 15 to each
condition and found the following:
MTB > desc c1 c2
Descriptive Statistics: exp, cont
Variable N Mean Median TrMean StDevSE Mean
exp 15 26.13 27.00 26.00
At 02:33 PM 9/13/01 +0100, Thom Baguley wrote:
>Rolf Dalin wrote:
> > Yes it would be the same debate. No matter how small the p-value it
> > gives very little information about the effect size or its practical
> > importance.
>
>Neither do standardized effect sizes.
agreed ... of course, we woul
Hi
On 13 Sep 2001, Rolf Dalin wrote:
> Hi, this is about Jim Clark's reply to dennis roberts.
> > I'm not sure how "both informative" gets translated into "neither
> > very informative." Seems like a perverse way of thinking to me.
> > Moreover, your original question was "then what benefit is
Rolf Dalin wrote:
> Yes it would be the same debate. No matter how small the p-value it
> gives very little information about the effect size or its practical
> importance.
Neither do standardized effect sizes.
Thom
=
Instructions
Hi, this is about Jim Clark's reply to dennis roberts.
> On 12 Sep 2001, dennis roberts wrote:
> > At 07:23 PM 9/12/01 -0500, jim clark wrote:
> > >What your table shows is that _both_ dimensions are informative.
> > >That is, you cannot derive effect size from significance, nor
> > >significance
Hi
On 12 Sep 2001, dennis roberts wrote:
> At 07:23 PM 9/12/01 -0500, jim clark wrote:
> >What your table shows is that _both_ dimensions are informative.
> >That is, you cannot derive effect size from significance, nor
> >significance from effect size. To illustrate why you need both,
> >consid
At 07:23 PM 9/12/01 -0500, jim clark wrote:
>Hi
>
>
>What your table shows is that _both_ dimensions are informative.
>That is, you cannot derive effect size from significance, nor
>significance from effect size. To illustrate why you need both,
>consider a study with small n that happened to get
Hi
On 12 Sep 2001, Dennis Roberts wrote:
> given a simple effect size calculation ... some mean difference compared to
> some pooled group or group standard deviation ... is it not possible to
> obtain the following combinations (assuming some significance test is done)
>
>
At 04:04 PM 9/12/01 -0400, you wrote:
if that is true ... then what benefit is there
to look at significance AT ALL
To get published, get tenure, and avoid having to live in a cardboard box
in the park. Ha ha!
Lise
given a simple effect size calculation ... some mean difference compared to
some pooled group or group standard deviation ... is it not possible to
obtain the following combinations (assuming some significance test is done)
effect size
small me
22 matches
Mail list logo
