Work

Generalized Cohen’s d for Multiple Means and Polytomous Settings

Year: 2026

Type: article

Abstract: Cohen’s d is the most commonly used estimator to quantify the magnitude of the difference between the means of two subpopulations. When comparing multiple populations simultaneously, Cohen’s f can be used for the same purpose. Using their relationship in the dichotomous setting, several general formulas for d are derived that generalize d to the polytomous setting. The traditional simplified estimator d = 2 f is studied as a shortcut estimator. It is strongly recommended to use the general formulas instead of the simplified ones when assessing the magnitude of the effect size, especially when the discrepancy of the extreme proportions of cases in the subpopulations exceeds 0.40.

Source: Applied Psychological Measurement

DOI: 10.1177/01466216261416025

Author: Jari Metsämuuronen

Institution: University of Turku

Language: English

Topic: Meta-analysis and systematic reviews

Subfield: Statistics, Probability and Uncertainty

Field: Decision Sciences

Domain: Social Sciences

Open Access status: hybrid

Estimated APC paid: $3,650

Funder: Academy of Finland