This function computes the standard error of a 2-group mean difference using the estimated means, estimated standard deviations, and sample sizes. The effect size estimate and standard error output from this function can be used as input in the meta.ave.gen, meta.lc.gen, and meta.lm.gen functions in applications where compatible mean differences from a combination of 2-group and paired-samples experiments are used in the meta-analysis. Equality of variances is not asumed.

se.mean2(m1, m2, sd1, sd2, n1, n2)

Arguments

m1

estimated mean for group 1

m2

estimated mean for group 2

sd1

estimated standard deviation for group 1

sd2

estimated standard deviation for group 2

n1

sample size for group 1

n2

sample size for group 2

Value

Returns a one-row matrix:

  • Estimate - estimated mean difference

  • SE - standard error

References

Snedecor GW, Cochran WG (1980). Statistical methods, 7th edition. ISU University Pres, Ames, Iowa.

Examples

se.mean2(21.9, 16.1, 3.82, 3.21, 40, 40)
#>                   Estimate        SE
#> Mean difference:       5.8 0.7889312

#                   Estimate        SE
# Mean difference:       5.8 0.7889312