lsr (version 0.5)

cramersV: Cramer's V

Description

Calculate the Cramer's V measure of association

Usage

cramersV(...)

Arguments

...

Arguments to be passed to the chisq.test function.

Value

A numeric variable with a single element corresponding to the value of V.

Warning

This package is under development, and has been released only due to teaching constraints. Until this notice disappears from the help files, you should assume that everything in the package is subject to change. Backwards compatibility is NOT guaranteed. Functions may be deleted in future versions and new syntax may be inconsistent with earlier versions. For the moment at least, this package should be treated with extreme caution.

Details

Calculates the Cramer's V measure of effect size for chi-square tests of association and goodness of fit. The arguments to the cramersV function are all passed straight to the chisq.test function, and should have the same format.

See Also

chisq.test, assocstats (in the vcd package)

Examples

# NOT RUN {
# Consider an experiment with two conditions, each with 100 
# participants. Each participant chooses between one of three
# options. Possible data for this experiment:

condition1 <- c(30, 20, 50) 
condition2 <- c(35, 30, 35)
X <- cbind( condition1, condition2 )
rownames(X) <- c( 'choice1', 'choice2', 'choice3' )
print(X)

# To test the null hypothesis that the distribution of choices
# is identical in the two conditions, we would run a chi-square
# test:
chisq.test(X)

# To estimate the effect size we can use Cramer's V:
cramersV( X )  # returns a value of 0.159


# }