文档介绍：Introduction to Meta-Analysis
Joseph Stevens, ., University of Oregon
(541) 346-2445, ******@
© Stevens 2006
What is Meta-Analysis (MA)?
Term coined by Gene Glass in his 1976 AERA Presidential address
An alternative to the traditional literature review
Allows the reviewer to bine and analyze the results from multiple studies
What is Meta-Analysis (MA)?
Traditional literature review is based on the reviewer’s analysis and synthesis of study themes or conclusions
MA collects the essential empirical results from multiple studies and draw conclusions about the “overall” effect across studies no matter what the original study conclusions were
Thus a MA es a research study on research studies, hence the term "meta".
Growth and Development of MA
MA has developed substantially both in methods and in applications (Larry Hedges, Ingram Olkin, John Hunter, and Frank Schmidt)
Literature review should be as systematic as primary research and study characteristics and design should provide a context for interpreting study results and conclusions (Glass)
MA now widely used in many disciplines (., education, social sciences, medicine)
Conducting a Meta-Analysis
Researcher first collects studies on a particular topic
Information about studies is then collated and coded
Results of each study are translated into mon metric, the study effect size
Analysis is then conducted to summarize effect size across studies or analyze relationships between covariates and effect size
Effects of MA
An important consequence of the development of MA is the way it has changed our thinking about research
Increased focus on a number of important issues in science including publication biases
How to understand and summarize statistical results
Importance of effect size and statistical power
Effect Size in MA
Effect size makes meta-analysis possible
it is the “dependent variable”
it standardizes findings across studies such that they can be pared
Any standardized index ca