Combining Correlation Matrices: Simulation Analysis of Improved Fixed-Effects Methods  

Oleh:

Hafdahl, Adam R.

Jenis: Article from Journal - ilmiah internasional
Dalam koleksi: Journal Of Educational And Behavioral Statistics vol. 32 no. 2 (Jun. 2007), page 180-205.
Topik: meta-analysis; correlation; generalized least squares; Monte Carlo study
Fulltext: 180.pdf (916.63KB)

Isi artikel

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 estimates of correlations in the conditional covariances. Fixed-effects methods with and without each refinement were examined in a Monte Carlo study; number of studies and the distribution of withinstudy sample sizes were varied. Both refinements improved element-wise point and interval estimates, as well as Type I error control for homogeneity tests, especially with many small studies. Practical recommendations and suggestions for future methodological work are offered. An appendix describes how to transform Fisher-Z (co)variances to the Pearson-r metric.

Opini Anda

Klik untuk menuliskan opini Anda tentang koleksi ini!

Kembali