ci.sign {statpsych}

Confidence interval for the parameter of the one-sample sign test

Description

Computes adjusted Wald interval for the population proportion of quantitative scores that are greater than the null hypothesis value of the population median in a one-sample sign test.

Usage

ci.sign(alpha, y, h)

Arguments

alpha

alpha level for 1-alpha confidence

y

vector of y scores

h

null hypothesis value for population median

Value

Returns a 1-row matrix. The columns are:

• Estimate - adjusted estimate of proportion

• SE - adjusted standard error

• LL - lower limit of adjusted Wald confidence interval

• UL - upper limit of adjusted Wald confidence interval

References

Agresti, A, & Coull, BA (1998) Approximate is better than “exact” for interval estimation of binomial proportions. American Statistician, 52, 119–126. doi: 10.1080/00031305.1998.10480550

Examples

y <- c(30, 20, 15, 10, 10, 60, 20, 25, 20, 30, 10, 5, 50, 40, 20, 10,
        0, 20, 50)
ci.sign(.05, y, 9)

# Should return:
# Estimate        SE        LL        UL
# 0.826087 0.0790342 0.6711828 0.9809911