NotesFAQContact Us
Collection
Advanced
Search Tips
Publication Date
In 20250
Since 20240
Since 2021 (last 5 years)0
Since 2016 (last 10 years)0
Since 2006 (last 20 years)3
Author
Hafdahl, Adam R.3
Williams, Michelle A.1
Education Level
Audience
Location
Laws, Policies, & Programs
Assessments and Surveys
What Works Clearinghouse Rating
Showing all 3 results Save | Export
Peer reviewed Peer reviewed
Direct linkDirect link
Hafdahl, Adam R. – Journal of Educational and Behavioral Statistics, 2008
Monte Carlo studies of several fixed-effects methods for combining and comparing correlation matrices have shown that two refinements improve estimation and inference substantially. With rare exception, however, these simulations have involved homogeneous data analyzed using conditional meta-analytic procedures. The present study builds on…
Descriptors: Monte Carlo Methods, Correlation, Matrices, Computation
Peer reviewed Peer reviewed
Direct linkDirect link
Hafdahl, Adam R.; Williams, Michelle A. – Psychological Methods, 2009
In 2 Monte Carlo studies of fixed- and random-effects meta-analysis for correlations, A. P. Field (2001) ostensibly evaluated Hedges-Olkin-Vevea Fisher-[zeta] and Schmidt-Hunter Pearson-r estimators and tests in 120 conditions. Some authors have cited those results as evidence not to meta-analyze Fisher-[zeta] correlations, especially with…
Descriptors: Monte Carlo Methods, Computer Software, Statistical Analysis, Correlation
Peer reviewed Peer reviewed
Direct linkDirect link
Hafdahl, Adam R. – Journal of Educational and Behavioral Statistics, 2007
The originally proposed multivariate meta-analysis approach for correlation matrices--analyze Pearson correlations, with each study's observed correlations replacing their population counterparts in its conditional-covariance matrix--performs poorly. Two refinements are considered: Analyze Fisher Z-transformed correlations, and substitute better…
Descriptors: Monte Carlo Methods, Correlation, Meta Analysis, Matrices