es_from_student_t function

Convert a Student's t-test value to several effect size measures

es_from_student_t(
  student_t,
  n_exp,
  n_nexp,
  smd_to_cor = "viechtbauer",
  reverse_student_t
)

Arguments

• student_t: Student's t-test value.
• 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 student_t value into a coefficient correlation (see details).
• reverse_student_t: a logical value indicating whether the direction of generated effect sizes should be flipped.

Returns

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 11. ANOVA statistics, Student's t-test, or point-bis correlation'
	https://metaconvert.org/html/input.html

Details

This function converts the Student's t-test value into a Cohen's d (D) and Hedges' g (G), Odds ratio (OR) and correlation coefficients (R/Z) are then converted from the Cohen's d.

To estimate a Cohen's d the formula used is (table 12.1 in Cooper):

$$cohen\_d = student\_t * \sqrt{\frac{(n\_exp+n\_nexp)}{n\_exp*n\_nexp}}$$

To estimate other effect size measures , calculations of the es_from_cohen_d() are applied.

Examples

es_from_student_t(student_t = 2.1, n_exp = 20, n_nexp = 22)

References

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