power_MADE {POMADE}

Power Approximation for Overall Average Effects in Meta-Analysis With Dependent Effect Sizes

Description

Compute power of the test of the overall average effect size in a meta-analysis of dependent effect size estimates, given a specified number of studies, effect size of practical concern, estimation method, and further assumptions about the distribution of studies.

Usage

power_MADE(
  J,
  mu,
  tau,
  omega,
  rho,
  alpha = 0.05,
  d = 0,
  model = "CHE",
  var_df = "RVE",
  sigma2_dist = NULL,
  n_ES_dist = NULL,
  iterations = 100,
  seed = NULL,
  warning = TRUE,
  average_power = TRUE
)

Arguments

J

Number of studies. Can be one value or a vector of multiple values.

mu

Effect size of practical concern. Can be one value or a vector of multiple values.

tau

Between-study SD. Can be one value or a vector of multiple values.

omega

Within-study SD. Can be one value or a vector of multiple values.

rho

Correlation coefficient between effect size estimates from the same study. Can be one value or a vector of multiple values.

alpha

Level of statistical significance. Can be one value or a vector of multiple values. Default is 0.05.

d

Contrast value. Can be one value or a vector of multiple values. Default is 0.

model

Assumed working model for dependent effect sizes, either "CHE" for the correlated-and-hierarchical effects model, "CE" for the correlated effects model, or "MLMA" for the multi-level meta-analysis model. Default is "CHE". Can be one value or a vector of multiple values.

var_df

Indicates the technique used to obtain the sampling variance of the average effect size estimate and the degrees of freedom, either "Model" for model-based variance estimator with degrees of freedom of J - 1, "Satt" for model-based variance estimator with Satterthwaite degrees of freedom, or "RVE" for robust variance estimator with Satterthwaite degrees of freedom. Default is "RVE". Can be one value or a vector of multiple values.

sigma2_dist

Distribution of sampling variance estimates from each study. Can be either a single value, a vector of plausible values, or a function that generates random values.

n_ES_dist

Distribution of the number of effect sizes per study. Can be either a single value, a vector of plausible values, or a function that generates random values.

iterations

Number of iterations per condition (default is 100).

seed

Numerical value for a seed to ensure reproducibility of the iterated power approximations.

warning

Logical indicating whether to return a warning when either sigma2_dist or n_ES_dist is based on balanced assumptions.

average_power

Logical indicating whether to calculate average power across the iterations for each condition.

Details

Find all background material behind the power approximations in Vembye, Pustejovsky, & Pigott (2022), including arguments for why it is suggested neither to conduct power analysis based on balanced assumptions about the number of effects per study and the study variance nor to use the original power approximation assuming independence among effect sizes (Hedges & Pigott, 2001).

Value

Returns a tibble with information about the expectation of the number of studies, the effect size of practical concern, the between-study and within-study variance components, the sample correlation, the contrast effect, the level of statistical significance, the sampling variance of overall average effect size of practical concern, the degrees of freedom, the power, the mcse, the number of iterations, the model to handle dependent effect sizes, and the methods used to obtain sampling variance estimates as well as the number effect sizes per study.

References

Vembye, M. H., Pustejovsky, J. E., & Pigott, T. D. (2022). Power approximations for overall average effects in meta-analysis with dependent effect sizes. Journal of Educational and Behavioral Statistics, 1–33. doi:10.3102/10769986221127379

Hedges, L. V., & Pigott, T. D. (2001). The power of statistical tests in meta-analysis. Psychological Methods, 6(3), 203–217. doi:10.1037/1082-989X.6.3.203

Examples

power <- power_MADE(
   J = c(40, 60),
   mu = 0.2,
   tau = 0.2,
   omega = 0.1,
   rho = 0.7,
   sigma2_dist = \(x) rgamma(x, shape = 5, rate = 10),
   n_ES_dist = \(x) 1 + stats::rpois(x, 5.5 - 1),
   model = c("CHE", "MLMA", "CE"),
   var_df = c("Model", "Satt", "RVE"),
   alpha = .05,
   seed = 10052510,
   iterations = 5
 )

power