文档介绍：What is Meta-analysis?
NCRM Research Methods Festival
University of Oxford
Prof. Herb Marsh
Ms. Alison O’Mara
Dr. Lars-Erik Malmberg
Dept of Education, University of Oxford
Primary versus secondary data analysis
Traditionally, social science researchers collect and analyse their own data (referred to as primary data). Secondary data analysis is based on data collected by someone else (or, perhaps, re-analysis of your own published data). There are at least four logical perspectives to this issue:
1. Meta-analysis -- systematic, quantitative review of published research in a particular field, the focus of this presentation.
2. Systematic review -- systematic, qualitative review of published research in a particular field
3. Secondary Data Analyses -- using large (typically public) databases
4. Re-analyses of published studies -- often in ways critical of the original study.
2
What is meta-analysis?
Systematic synthesis of various studies on a particular research question
Do boys or girls have higher self-concepts?
Collect all studies relevant to a topic
Find all published journal articles on the topic
An effect size (the ‘dependent variable’) is calculated for each e
Determine the size/direction of gender difference for each study
“Content analysis”
code characteristics of the study; age, setting, ethnicity, self-concept domain (math, physical, social), etc.
Effect sizes with similar features are grouped together pared; tests moderator variables
Do gender differences vary with age, setting, ethnicity, self-concept, domain, etc.
3
A blend of qualitative and quantitative approaches
Coding: the process of extracting the information from the literature included in the meta-analysis. Involves noting the characteristics of the studies in relation to a priori variables of interest (qualitative)
Effect size: the numerical e to be analysed in a meta-analysis; a summary statistic of the data in each study included in the meta-analysis (quantitative)
Summari