Bootstrap confidence interval for eta squared

Percentile bootstrap for the proportion of variance in outcome explained by group, resampling observations jointly so the group structure travels with each resample.

Usage

eta_sq_ci(outcome, group, R = 2000, conf.level = 0.95, seed = NULL)

Arguments

outcome

A numeric vector.

group

A grouping vector of the same length.

R

Integer. Number of bootstrap resamples. Defaults to 2000.

conf.level

Confidence level. Defaults to 0.95.

seed

Integer or NULL. When supplied, sets the random seed.

Value

A named numeric vector: estimate, lower, upper, with attributes resamples, valid_resamples and, when the interval is withheld, reason. The bounds are NA when fewer than 90% of resamples give a value, or when every resample gives the same value, since neither leaves a sampling distribution to read. The bounds are NA with fewer than 3 complete observations or fewer than 2 groups.

See also

bootstrap_ci()

Examples

eta_sq_ci(mtcars$mpg, mtcars$cyl, seed = 42)
#>  estimate     lower     upper 
#> 0.7324601 0.6316254 0.8460837 
#> attr(,"resamples")
#> [1] 2000
#> attr(,"valid_resamples")
#> [1] 2000