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Let's say that I, for a meta-analysis, have two effect sizes, $ES_1$ and $ES_2$ (begin standardized mean differences) with standard errors, $SE_1$ and $SE_2$, and that I want to combine these into a s …

In Borenstein et al's (2009) Introduction to meta-analysis, page 263, one can read the following: A power analysis should be performed when the review is being planned, and not after the review ha …

In most meta-analyses that I've read, the authors choose to exclude studies with really small sample sizes (e.g n=10). Why is that? Speculation I could speculate that one reason is that since the ef …

I have gathered data from a number of studies where two different groups have performed the same task. For each group in each study, I have number of observations as well as the mean and standard devi …

I'm running a multi-level moderator meta-analysis using the R package metafor. To derive $I^2$ for the metafor analysis as a whole, which doesn't come out automatically for multi-level models, I've us …

I have the following example data, stored in the variable TheData: Study d Variance Category 1 0 0.1 A 1 5 0.1 B 1 10 0.1 C 2 20 …

In this thread, it is proposed that if you don't know what the variance-covariance matrix looks like for a dataset that you want to run a multi-level meta-analysis on, you can, among other things, "ma …

I have the following example data, stored in the variable TheData, Study ID Category Cohens_d Variance 1 1 A 0 0.1 1 2 B 5 …

I have a dataset that I want to run a meta-analysis on. However, the data has a hierarchical structure with several endpoints per study and where studies are further clustered together. So, I should r …

A while ago I posted a question regarding performing post-hoc power analyses in meta-analyses and was given a couple of useful links to discussions regarding why this isn’t a good idea. From my readin …

My dataset I have a dataset where Effect sizes are nested in Testing occasions, which are nested in Samples of participants, which in turn are nested in Studies (that is, Effect sizes ⟶ Testing occas …

If you want to perform a meta-analysis on the general strength of the population and where each study can offer multiple outcomes (for example, measuring strength through deadlift capability and/or th …

Normally, I would say that variance (and, in extension, standard deviation since it's just the square root of the variance) refers to a measure of deviation that describes how data points within a sam …

Let's say that I'm conducting a meta-analysis, looking at the performance of group A and group B with respect to a certain construct. Now, some of the studies that I'll come across will report that no …