tau_squared {kim}

Tau-squared (between-studies variance for meta analysis)

Description

Calculate tau-squared, the between-studies variance (the variance of the effect size parameters across the population of studies), as illustrated in Borenstein et al. (2009, pp. 72-73, ISBN: 978-0-470-05724-7).

Usage

tau_squared(effect_sizes = NULL, effect_size_variances = NULL)

Arguments

effect_sizes

effect sizes (e.g., standardized mean differences)

effect_size_variances

within-study variances

Details

Negative values of tau-squared are converted to 0 in the output (see Cheung, 2013; https://web.archive.org/web/20230512225539/https://openmx.ssri.psu.edu/thread/2432)

Examples

## Not run: 
tau_squared(effect_sizes = c(1, 2), effect_size_variances = c(3, 4))
# a negative tau squared value is converted to 0:
tau_squared(effect_sizes = c(1.1, 1.4), effect_size_variances = c(1, 4))

## End(Not run)