ci.yule {statpsych}

Confidence intervals for generalized Yule coefficients

Description

Computes confidence intervals for four generalized Yule measures of association (Yule Q, Yule Y, Digby H, and Bonett-Price Y*) using a transformation of a confidence interval for an odds ratio with .5 added to each cell frequency. This function requires the frequency counts from a 2 x 2 contingency table for two dichotomous variables. Digby H is sometimes used as a crude approximation to the tetrachoric correlation. Yule Y is equal to the phi coefficient only when all marginal frequencies are equal. Bonett-Price Y* is a better approximation to the phi coeffiient when the marginal frequencies are not equal.

Usage

ci.yule(alpha, f00, f01, f10, f11)

Arguments

alpha

alpha level for 1-alpha confidence

f00

number of participants with y = 0 and x = 0

f01

number of participants with y = 0 and x = 1

f10

number of participants with y = 1 and x = 0

f11

number of participants with y = 1 and x = 1

Value

Returns a 1-row matrix. The columns are:

• Estimate - estimate of generalized Yule coefficient

• SE - standard error

• LL - lower limit of the confidence interval

• UL - upper limit of the confidence interval

References

Bonett DG, Price RM (2007). “Statistical inference for generalized Yule coefficients in 2x2 contingency tables.” Sociological Methods & Research, 35(3), 429–446. ISSN 0049-1241, doi:10.1177/0049124106292358.

Examples

ci.yule(.05, 229, 28, 96, 24)

# Should return:
#      Estimate         SE         LL        UL
# Q:  0.3430670 0.13280379 0.06247099 0.5734020
# Y:  0.1769015 0.07290438 0.03126603 0.3151817
# H:  0.2619244 0.10514465 0.04687994 0.4537659
# Y*: 0.1311480 0.05457236 0.02307188 0.2361941