Re: significance of correlation affected by sample size?

In article <1132843929.037229.164490@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>,
Thom <t.s.baguley@xxxxxxxxxxx> wrote:
>Conceptually:

>Statistical significance = effect size x sample size

A far more correct statement is that the "statistical
significance" is approximately a function of the effect
size multiplied by the square root of the sample size.

Even this is not a good guide as to what action should
be taken. To get that, one should look upon the
problem as a decision problem.

>e.g., in concrete form

>t = d x (df^0.5)/2 ... (for independent t using Cohen's d)

>... as d or df increases t (and statistical significance) increases ...

>This is taken straight from Robert Rosenthal's book chapter in the
>Handbook of Research Synthesis.



>Thom



--
This address is for information only. I do not claim that these views
are those of the Statistics Department or of Purdue University.
Herman Rubin, Department of Statistics, Purdue University
hrubin@xxxxxxxxxxxxxxx Phone: (765)494-6054 FAX: (765)494-0558
.

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