seritdiff {ridittools}

Compute standard error of difference between two mean ridits

Description

Computes the approximate standard error of the difference between the mean ridits of two groups. This does not depend on the reference group the mean ridits are relative to, only on the sizes of the two groups.

Usage

seriditdiff(g1, g2)

Arguments

g1

vector of counts (not ridits) for first group

g2

vector of counts (not ridits) for second group

Details

the order of the two groups doesn't matter.

Value

approximate standard error of difference between mean ridits

Author(s)

Eric Bohlman

References

Fleiss, J.,L., (1981), Statistical Methods for Rates and Proportions. New York: John Wiley & Sons., p. 155

Examples

seriditdiff(semiauto[ , "Ind"], semiauto[ , "Rep"])

## The function is currently defined as
function(g1, g2) {
  sqrt(sum(g1) + sum(g2)) / (2 * sqrt(3 * sum(g1) * sum(g2)))
}