R: Power Calculations for ChiSquared Tests

power.chisq.test {DescTools} | R Documentation

## Power Calculations for ChiSquared Tests

### Description

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

### Usage

    power.chisq.test(n = NULL, w = NULL, df = NULL, sig.level = 0.05, power = NULL)

### Arguments

`n` | total number of observations.
`w` | effect size.
`df` | degree of freedom (depends on the chosen test.
`sig.level` | Significance level (Type I error probability).
`power` | Power of test (1 minus Type II error probability).

### Details

Exactly one of the parameters `w`, `n`, `power` or `sig.level` must be passed as NULL, and this parameter is determined from the others. Note 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's work on power.t.test

### References

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

### See Also

`power.t.test`

### Examples

    ## Exercise 7.1 P. 249 from Cohen (1988)
    power.chisq.test(w=0.289, df=(4-1), n=100, sig.level=0.05)

    ## Exercise 7.3 p. 251
    power.chisq.test(w=0.346, df=(2-1)*(3-1), n=140, sig.level=0.01)

    ## Exercise 7.8 p. 270
    power.chisq.test(w=0.1, df=(5-1)*(6-1), power=0.80, sig.level=0.05)

[Package DescTools version 0.99.36 Index]