R: Power calculations for balanced one-way analysis of variance...

pwr.anova.test {pwr} | R Documentation

## Power calculations for balanced one-way analysis of variance tests

### Description

Compute power of test or determine parameters to obtain target power (same as power.anova.test).

### Usage

    pwr.anova.test(k = NULL, n = NULL, f = NULL, sig.level = 0.05, power = NULL)

### Arguments

`k` | Number of groups
`n` | Number of observations (per group)
`f` | Effect size
`sig.level` | Significance level (Type I error probability)
`power` | Power of test (1 minus Type II error probability)

### Details

Exactly one of the parameters 'k','n','f','power' and 'sig.level' must be passed as NULL, and that parameter is determined from the others. Notice that the last one has non-NULL default so NULL must be explicitly passed if you want to compute it.

### Value

Object of class '"power.htest"', a list of the arguments (including the computed one) augmented with 'method' and 'note' elements.

### Note

'uniroot' is used to solve power equation for unknowns, so you may see errors from it, notably about inability to bracket the root when invalid arguments are given.

### Author(s)

Stephane Champely <champely@univ-lyon1.fr> but this is a mere copy of Peter Dalgaard work (power.t.test)

### References

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

### See Also

power.anova.test

### Examples

    ## Exercise 8.1 P. 357 from Cohen (1988)
    pwr.anova.test(f=0.28,k=4,n=20,sig.level=0.05)

    ## Exercise 8.10 p. 391
    pwr.anova.test(f=0.28,k=4,power=0.80,sig.level=0.05)

[Package pwr version 1.2-2 Index]