es_from_ancova_means_sd_pooled_adj: Convert means and adjusted pooled standard deviation of two...

In metaConvert: An Automatic Suite for Estimation of Various Effect Size Measures

Convert means and adjusted pooled standard deviation of two independent groups obtained from an ANCOVA model into several effect size measures

Description

Convert means and adjusted pooled standard deviation of two independent groups obtained from an ANCOVA model into several effect size measures

Usage

es_from_ancova_means_sd_pooled_adj(
  ancova_mean_exp,
  ancova_mean_nexp,
  ancova_mean_sd_pooled,
  cov_outcome_r,
  n_cov_ancova,
  n_exp,
  n_nexp,
  smd_to_cor = "viechtbauer",
  reverse_ancova_means
)

Arguments

ancova_mean_exp	adjusted mean of participants in the experimental/exposed group.
ancova_mean_nexp	adjusted mean of participants in the non-experimental/non-exposed group.
ancova_mean_sd_pooled	adjusted pooled standard deviation.
cov_outcome_r	correlation between the outcome and covariate(s) (multiple correlation when multiple covariates are included in the ANCOVA model).
n_cov_ancova	number of covariates in the ANCOVA model.
n_exp	number of participants in the experimental/exposed group.
n_nexp	number of participants in the non-experimental/non-exposed group.
smd_to_cor	formula used to convert the adjusted cohen_d value into a coefficient correlation (see details).
reverse_ancova_means	a logical value indicating whether the direction of the generated effect sizes should be flipped.

Details

This function converts the adjusted pooled standard deviations of two independent groups into a crude pooled standard deviation. and then relies on the calculations of the es_from_ancova_means_sd_pooled_crude() function.

To convert the adjusted pooled SD into a crude pooled SD (table 12.3 in Cooper):

mean\_sd\_pooled = \frac{ancova\_mean\_sd\_pooled}{\sqrt{1 - cov\_outcome\_r^2}}

Calculations of the es_from_ancova_means_sd_pooled_crude() are then applied.

Value

This function estimates and converts between several effect size measures.

natural effect size measure	MD + D + G
converted effect size measure	OR + R + Z
required input data	See 'Section 19. Adjusted: Means and dispersion'
	https://metaconvert.org/input.html

References

Cooper, H., Hedges, L.V., & Valentine, J.C. (Eds.). (2019). The handbook of research synthesis and meta-analysis. Russell Sage Foundation.

Examples

es_from_ancova_means_sd_pooled_adj(
  ancova_mean_exp = 98, ancova_mean_nexp = 87,
  ancova_mean_sd_pooled = 17, cov_outcome_r = 0.2,
  n_cov_ancova = 3, n_exp = 20, n_nexp = 20
)

metaConvert documentation built on April 12, 2025, 1:09 a.m.