All Questions
6 questions
3
votes
2
answers
959
views
Confidence interval for one-sample effect size: effect of uncertainty of variation?
I have a one sample t-test (against null-hypothesis value 0) for which I would like to calculate the confidence interval on Cohen's d. I know the formula for Cohen's d (sample mean minus zero all ...
- 997
2
votes
0
answers
301
views
Variance pooling in Cohen's d
I have a question about the use of pooled variance in Cohen's d effect size metric. Pooled variance assumes both samples are coming from populations of same variance. They quantified this as no one ...
- 21
5
votes
3
answers
6k
views
Cohen's d for unequal variance
I know my two samples have unequal variance. Should I consider this in my calculation of the effect size? I'm using Cohen's d, which Wikipedia defines as
$d = \frac{\bar{x}_1 - \bar{x}_2}{s}$
with
...
- 607
1
vote
0
answers
262
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Pooled Variance for Dependent $t$-test statistic?
I'm looking into finding a way to calculate Cohen's $d$ for correlated samples.
Assuming pooled variances, we end up getting
$$\text{SE}\left( \Delta \text{ of means}\right) = S_p\sqrt{\dfrac{1}{n_1}...
- 5,147
13
votes
1
answer
9k
views
Variance of Cohen's $d$ statistic
Cohen’s $d$ is one of the most common ways we measure the size of an effect (see Wikipedia). It simply measures the distance between two means in terms of the pooled standard deviation. How can we ...
- 613
5
votes
0
answers
657
views
Does pooled variance correct for/protect from unequal variance when calculating effect size?
This may be a lame question, but I got stuck and can't get my head around it. I am running a gene expression analysis, comparing $\sim 10,000$ genes between two groups, $n=6$ samples per group. My ...
- 211