seridit {ridittools}

Compute standard error of mean ridit for group given reference group

Description

Given a vector of counts for a group and a vector of counts for a reference group, computes the standard error of the mean ridit for the group.

Usage

seridit(v, ref)

Arguments

v

same as meanridit(), but must be counts

ref

same as meanridit(), but must be counts

Value

standard error of mean ridit

Author(s)

Eric Bohlman

References

Fleiss, J.,L., (1981), Statistical Methods for Rates and Proportions. New York: John Wiley & Sons, p. 154

Examples

# PolitiFact ratings in order of increasing truthfulness (8 Mar 2018)
obama <- c(9, 71, 70, 161, 165, 123)
trump <- c(77, 169, 114, 78, 60, 24)
# Result is approximately standard normal
(meanridit(trump, obama) - 0.5) / seridit(trump, obama)

## The function is currently defined as
function (v, ref)
{
    N <- sum(ref)
    n <- sum(v)
    term1 <- (n + 1)/N
    term2 <- 1/(N * (N + n - 1))
    term3 <- sum((ref + v)^3)/(N * (N + n) * (N + n - 1))
    (1/(2 * sqrt(3 * n))) * sqrt(1 + term1 + term2 - term3)
  }