v {esvis} | R Documentation |
Calculate the V effect size statistic
Description
This function calculates the effect size V, as discussed by
Ho, 2009. The V
statistic is a transformation of auc
, interpreted as the
average difference between the distributions in standard deviation units.
Usage
v(data, formula, ref_group = NULL)
Arguments
data |
The data frame used for estimation - ideally structured in a tidy format. |
formula |
A formula of the type |
ref_group |
Optional. A character vector or forumla listing the
reference group levels for each variable on the right hand side of the
formula, supplied in the same order as the formula. Note that if using the
formula version, levels that are numbers, or include hyphens, spaces, etc.,
should be wrapped in back ticks (e.g.,
|
Value
By default the V statistic for all possible pairings of the grouping factor are returned as a tidy data frame. Alternatively, a vector can be returned, and/or only the V corresponding to a specific reference group can be returned.
Examples
# Calculate V for all pairwise comparisons
v(star, reading ~ condition)
# Report only relative to regular-sized classrooms
v(star,
reading ~ condition,
ref_group = "reg")
# Report by ELL and FRL groups for each season, compare to non-ELL students
# who were not eligible for free or reduced price lunch in the fall (using
# the formula interface for reference group referencing).
## Not run:
v(benchmarks,
math ~ ell + frl + season,
ref_group = ~`Non-ELL` + `Non-FRL` + Fall)
# Same thing but with character vector supplied, rather than a formula
v(benchmarks,
math ~ ell + frl + season,
ref_group = c("Non-ELL", "Non-FRL", "Fall"))
## End(Not run)