R: Conventional effects size

cohen.ES {pwr} | R Documentation

## Conventional effects size

### Description

Give the conventional effect size (small, medium, large) for the tests available in this package

### Usage

    cohen.ES(test = c("p", "t", "r", "anov", "chisq", "f2"),
        size = c("small", "medium", "large"))

### Arguments

`test` | The statistical test of interest
`size` | The ES : small, medium of large?

### Value

The corresponding effect size

### Author(s)

Stephane CHAMPELY

### References

Cohen, J. (1988). Statistical power analysis for the behavioral sciences (2nd ed.). Hillsdale,NJ: Lawrence Erlbaum.

### Examples

    ## medium effect size for the correlation test
    cohen.ES(test="r", size="medium")

    ## sample size for a medium size effect in the two-sided correlation test
    ## using the conventional power of 0.80
    pwr.r.test(r=cohen.ES(test="r",size="medium")$effect.size,
      power=0.80, sig.level=0.05, alternative="two.sided")

[Package pwr version 1.2-2 Index]