# Tagged Questions

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### How to “explain away” an effect size using an independent variable?

I have many measures of Y for two groups A and B. Following the more modern approach of research in education, I calculated the effect size of the difference of Y for both groups (Cohen's d), and the ...
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### Pearson correlation is not significant although effect is .30 What could be the reason?

I have a correlation between two variables of 0.30, hence a medium effect. but it is not statistically significant and I want to report the reasons for that. looking at the test statistic I see that ...
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### Literature to support effect size over significance

In a large sample (N = 3,265,506 for my study) tests are always significant. Is there an article in the literature I can cite to justify using effect size instead of significance testing?
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### What is the most appropriate way to test significance of effect difference across two groups?

Here is the question: After running two separate OLS regressions, one for each group (male vs. female), we get coefficient b1 for a specific IV in "male" regression, and coefficient b2 for the same IV ...
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### Am I using the wrong statistical test?

I am using $\chi^2$ to analyze a set of data gathered over 4 time periods. The two variables are independent--each 'event' is categorized as 'good' or 'bad'. We want to prove that the intervention ...
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### How to assess whether two treatments are significantly different using Cohen's d (effect size)?

Cohen's d is a measure of effect size calculated as: $d = (x_1-x_2) / \sigma_{\text{pooled}}$ where $x_1$ is the mean of one group, $x_2$ is the mean of a second group, and $\sigma_{\text{pooled}}$ ...
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### Effect size and statistical significance

Using Cohen's d, I am getting small amd medium effect sizes for results that are statistically non-significant (p>.05). Does this make sense?