es_from_paired_t {metaConvert} | R Documentation |
Convert two paired t-test value of two independent groups into several effect size measures
Description
Convert two paired t-test value of two independent groups into several effect size measures
Usage
es_from_paired_t(
paired_t_exp,
paired_t_nexp,
n_exp,
n_nexp,
r_pre_post_exp,
r_pre_post_nexp,
smd_to_cor = "viechtbauer",
reverse_paired_t
)
Arguments
paired_t_exp |
Paired t-test value of the experimental/exposed group. |
paired_t_nexp |
Paired t-test value of the non-experimental/non-exposed group. |
n_exp |
number of participants in the experimental/exposed group. |
n_nexp |
number of participants in the non-experimental/non-exposed group. |
r_pre_post_exp |
pre-post correlation in the experimental/exposed group |
r_pre_post_nexp |
pre-post correlation in the non-experimental/non-exposed group |
smd_to_cor |
formula used to convert the |
reverse_paired_t |
a logical value indicating whether the direction of generated effect sizes should be flipped. |
Details
This function converts paired t-tests of two independent groups value into a Cohen's d (D) and Hedges' g (G) (table 12.2 in Cooper). Odds ratio (OR) and correlation coefficients (R/Z) are then converted from the Cohen's d.
To estimate the Cohen's d, the following formulas are used (Cooper et al., 2019):
cohen\_d\_exp = paired\_t\_exp * \sqrt{\frac{2 * (1 - r\_pre\_post\_exp)}{n\_exp}}
cohen\_d\_nexp = paired\_t\_nexp * \sqrt{\frac{2 * (1 - r\_pre\_post\_nexp)}{n\_nexp}}
cohen\_d\_se\_exp = \sqrt{\frac{2 * (1 - r\_pre\_post\_exp)}{n\_exp} + \frac{d\_exp^2}{2 * n\_exp}}
cohen\_d\_se\_nexp = \sqrt{\frac{2 * (1 - r\_pre\_post\_nexp)}{n\_nexp} + \frac{d\_nexp^2}{2 * n\_nexp}}
cohen\_d = d\_exp - d\_nexp
d\_se = \sqrt{cohen\_d\_se\_exp^2 + cohen\_d\_se\_nexp^2}
To estimate other effect size measures,
calculations of the es_from_cohen_d()
are applied.
Value
This function estimates and converts between several effect size measures.
natural effect size measure | D + G |
converted effect size measure | OR + R + Z |
required input data | See 'Section 16. Paired: Paired F- or t-test' |
https://metaconvert.org/html/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_paired_t(paired_t_exp = 2.1, paired_t_nexp = 4.2, n_exp = 20, n_nexp = 22)