Accuracy of Conversion Formula for Effect Sizes: A Monte Carlo Simulation

Autor/inn/en	Poom, Leo; af Wåhlberg, Anders
Titel	Accuracy of Conversion Formula for Effect Sizes: A Monte Carlo Simulation
Quelle	In: Research Synthesis Methods, 13 (2022) 4, S.508-519 (12 Seiten)Infoseite zur Zeitschrift PDF als Volltext Verfügbarkeit
Zusatzinformation	ORCID (Poom, Leo) ORCID (af Wåhlberg, Anders)
Sprache	englisch
Dokumenttyp	gedruckt; online; Zeitschriftenaufsatz
ISSN	1759-2879
DOI	10.1002/jrsm.1560
Schlagwörter	Meta Analysis; Effect Size; Mathematical Formulas; Monte Carlo Methods; Sampling; Accuracy; Computation; Statistical Analysis; Statistical Bias + Suchen Sie Ihr Suchwort? Meta-analysis; Metaanalyse; Mathematische Formel; Monte-Carlo-Methode; Statistische Analyse
Abstract	In meta-analysis, effect sizes often need to be converted into a common metric. For this purpose conversion formulas have been constructed; some are exact, others are approximations whose accuracy has not yet been systematically tested. We performed Monte Carlo simulations where samples with pre-specified population correlations between the "x" and "y"-variables were drawn from a normally distributed population. A number of commonly used effect size measures and statistics were calculated from each sample. Using several available conversion formula these statistics were converted into Pearson "r" and Cohen's "d" and compared to "r" and "d" calculated directly from the original data. Converted values were systematically lower than the directly calculated values. While conversions to "d" were quite accurate, some of the conversions to "r" resulted in large biases. These systematic errors can in most cases be adjusted for by simply multiplying the converted values with a corresponding correction factor. (As Provided).
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Erfasst von	ERIC (Education Resources Information Center), Washington, DC
Update	2024/1/01