This document provides an introduction and overview of meta-analysis. It discusses that meta-analysis allows researchers to combine results from multiple studies examining the same topic. The document outlines the basic steps of meta-analysis, including searching the literature to identify relevant studies, choosing an effect size statistic to combine results, calculating and presenting summary statistics using forest plots, and addressing potential biases. Meta-analysis has become popular for synthesizing evidence in fields like education and medicine and is increasingly being used in applied ecology.

1. Meta-Analysis: An Introduction Bob O'Hara

2. Useful References Harrison, F. (2011) Getting started with meta-analysis. Methods in Ecology and Evolution 2 : 1–10 http://dx.doi.org/10.1111/j.2041-210X.2010.00056.x Podcast: http://bdown.astream.com/mee/fharrison.mp3 Stewart, G. (2010) Meta-analyses in applied ecology. Biol. Letters 6 : 78-81 http://dx.doi.org/10.1111/10.1098/rsbl.2009.0546

3. The Problem: lots of studies of the same thing

4. We want to combine the studies “ Evidence synthesis”

5. Meta-analyses let us do this

6. “Meta-analysis” introduced in 1976 Glass, G.V. (1976) Primary, Secondary, and Meta-Analysis of Research. Educational Researcher 5 : 3-8. http://dx.doi.org/10.3102/0013189X005010003

7. ...but the idea is much older Simpson, R.J.S. & Pearson, K. (1904) Report On Certain Enteric Fever Inoculation Statistics. The British Medical Journal 2 : 1243-1246 http://www.jstor.org/stable/20282622

8. Popular in Education and Medicine

11. How to do it In 3 ½ steps

15. Have to interpret on the same scale

21. Finally: write it up

22. Finally: write it up ...and hide it in your bottom drawer