d_to_r {effectsize} | R Documentation |
Enables a conversion between different indices of effect size, such as standardized difference (Cohen's d), (point-biserial) correlation r or (log) odds ratios.
d_to_r(d, n1, n2, ...) r_to_d(r, n1, n2, ...) oddsratio_to_d(OR, log = FALSE, ...) logoddsratio_to_d(OR, log = TRUE, ...) d_to_oddsratio(d, log = FALSE, ...) oddsratio_to_r(OR, n1, n2, log = FALSE, ...) logoddsratio_to_r(OR, log = TRUE, ...) r_to_oddsratio(r, n1, n2, log = FALSE, ...)
d |
Standardized difference value (Cohen's d). |
n1, n2 |
Group sample sizes. If either is missing, groups are assumed to be of equal size. |
... |
Arguments passed to or from other methods. |
r |
Correlation coefficient r. |
OR |
Odds ratio values in vector or data frame. |
log |
Take in or output the log of the ratio (such as in logistic models). |
Conversions between d and OR is done through these formulae:
d = log(OR) * sqrt(3) / pi
log(OR) = d * pi / sqrt(3)
Converting between d and r is done through these formulae:
d = sqrt(h) * r / sqrt(1 - r^2)
r = d / sqrt(d^2 + h)
Where h = (n1 + n2 - 2) / n1 + (n1 + n2 - 2) / n2. When groups are of equal size, h reduces to approximately 4. The resulting r is also called the binomial effect size display (BESD; Rosenthal et al., 1982).
Converted index.
Borenstein, M., Hedges, L. V., Higgins, J. P. T., & Rothstein, H. R. (2009). Converting among effect sizes. Introduction to meta-analysis, 45-49.
Jacobs, P., & Viechtbauer, W. (2017). Estimation of the biserial correlation and its sampling variance for use in meta‐analysis. Research synthesis methods, 8(2), 161-180. doi: 10.1002/jrsm.1218
Rosenthal, R., & Rubin, D. B. (1982). A simple, general purpose display of magnitude of experimental effect. Journal of educational psychology, 74(2), 166.
Sánchez-Meca, J., Marín-Martínez, F., & Chacón-Moscoso, S. (2003). Effect-size indices for dichotomized outcomes in meta-analysis. Psychological methods, 8(4), 448.
Other convert between effect sizes:
diff_to_cles
,
eta2_to_f2()
,
odds_to_probs()
,
oddsratio_to_riskratio()
r_to_d(0.5) d_to_oddsratio(1.154701) oddsratio_to_r(8.120534) d_to_r(1) r_to_oddsratio(0.4472136, log = TRUE) oddsratio_to_d(1.813799, log = TRUE)