# Meta-Analysis Resources

Tools for Those Who Summarize the Evidence Base

Resources and networking for those who conduct or interpret meta-analyses related to any phenomenon that is gauged in multiple studies.

Emilie Champagne
• Québec

27 members

# Emilie Champagne's Page

## Latest Activity

Emilie Champagne added a discussion to the group Calculating Effect Sizes and Their Variances

### Converting from r to d

Hi everybody,I am looking for references concerning the transformation of r-type effect size into d-type.My meta-analysis encompass multiple type of data, some presented as differences of means, others as Pearson's r. As d-type are more frequent, I converted all effect size into d, using Borenstein et al 2009 equations. But as this is rarely done, I would like to back myself with good references.Do you know of anything like that ? Would you advise against converting ?Thanks !EmilieSee More
Jul 16, 2014
"Right, it cannot be calculated with the zero cell. When I calculate the OR using dstat 2, I come up with the same OR (and implied variance). This OR of 0.0034 converts to an SMD of 3.278, and a 95% CI of 2.61 to 3.95, so the underlying variance…"
Jun 9, 2014
"I realize that I was probably doing the correction wrong, so finally, it might be okay (great!).Just to help anyone who would find this post, here's an exemple: My data are percentage plant individual browsed by herbivore with or without…"
Jun 6, 2014
"Can you give me an example 2 x 2 table that exhibits the problem?"
Jun 6, 2014
"Thanks. I tried it (partially for the moment), but it still greatly increase the variance and bring the weight to 0. I wished their would be something else to do. I read a bit about the Peto method, that estimate OR differently and can handle 0, but…"
Jun 6, 2014
"Oh, I see. There is something called the Haldane Correction to solve the problem. Essentially you add 0.5 to each cell frequency, and that gets rid of the zero n problem. Here's a link describing it."
Jun 5, 2014
"Sorry, I was unclear. Some of the data used to compute the OR are 0. So if I refer to the Borenstein nomenclature for the equation : Table 5.1 Nomenclature for 2 2 table of outcome by treatment.                   Events   Non-Events    …"
Jun 5, 2014
"I thought that with ORs, 0 is infinity so it cannot appear. Yes, an OR of 0 would be astronomical in size! How is it possible that a report would give a zero for an OR, unless it is a typographical error? (Rounding?)"
Jun 5, 2014
Emilie Champagne added a discussion to the group Calculating Effect Sizes and Their Variances

### Complex effect size conversion

Hi everybody,I am really happy to finally find somewhere where my meta-analysis questions could find an answer. I'm new to meta-analyzing, but I have read multiple books on the subject while starting my own and I cannot find anything close to what I am trying to do. I might mean that it is not "ok", not correct according to statistic or to meta-analysis standart and if so, I hope somebody will be able to point it out to me.The data I'm dealing with comes from different experiment types, most of…See More
Jun 5, 2014
Emilie Champagne joined Blair T. Johnson's group

### Calculating Effect Sizes and Their Variances

Tips and techniques to help meta-analysts calculate effect sizes and the variances that are needed for the purpose of analysis.See More
Jun 5, 2014
Emilie Champagne updated their profile
Jun 5, 2014
Emilie Champagne is now a member of Meta-Analysis Resources
Jun 5, 2014

## Profile Information

I'm an ecologist currently working on her first meta-analysis. My objective is to find how spatial scale (plot size) can influence neighboring effects on plant susceptibility to browsing by large herbivores.

## Comment Wall (1 comment)

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