R: Vargha and Delaney A measure

VD.A {effsize} | R Documentation

## Vargha and Delaney A measure

### Description

Computes the Vargha and Delaney A effect size measure.

### Usage

    VD.A(d, ...)

    ## S3 method for class 'formula'
    VD.A(formula,data=list(), ...)

    ## Default S3 method:
    VD.A(d,f, ...)

### Arguments

`d` | a numeric vector giving either the data values (if `f` is a factor) or the treatment group values (if `f` is a numeric vector)
`f` | either a factor with two levels or a numeric vector of values
`formula` | a formula of the form `y ~ f`, where `y` is a numeric variable giving the data values and `f` a factor with two levels giving the corresponding group
`data` | an optional matrix or data frame containing the variables in the formula `formula`. By default the variables are taken from `environment(formula)`.
`...` | further arguments to be passed to or from methods.

### Details

The function computes the Vargha and Delaney A effect size measure (Vargha and Delaney, 2000).

### Value

A list of class `effsize` containing the following components:

`estimate` | the A statistics estimate
`magnitude` | a qualitative assessment of the magnitude of effect size
`method` | the method used, i.e. `"Vargha and Delaney A"`

### Author(s)

Marco Torchiano http://softeng.polito.it/torchiano/

### References

A. Vargha and H. D. Delaney. "A critique and improvement of the CL common language effect size statistics of McGraw and Wong." Journal of Educational and Behavioral Statistics, 25(2):101-132, 2000

### See Also

`cliff.delta`, `cohen.d`, `print.effsize`

### Examples

    treatment = rnorm(100,mean=10)
    control = rnorm(100,mean=12)
    d = (c(treatment,control))
    f = rep(c("Treatment","Control"),each=100)
    ## compute Vargha and Delaney A
    ## treatment and control
    VD.A(treatment,control)
    ## data and factor
    VD.A(d,f)
    ## formula interface
    VD.A(d ~ f)

[Package effsize version 0.7.1 Index]