# Sample size estimation in the differences between proportions

### Description

`samplesize.h`

determines the sample size, when specified the effect size to be detected, desired statistical power, and significance level.
`samplesize.h`

always specifies two-sided test.

### Usage

1 | ```
samplesize.h(delta, power = 0.8, sig.level = 0.05)
``` |

### Arguments

`delta` |
a numeric contains the effect size (Cohen's |

`power` |
a numeric contains the desired statistical power (default 0.80) |

`sig.level` |
a numeric contains the significance level (default 0.05) |

### Value

Return a numeric containing the appropriate sample size in each group.

### Author(s)

Yasuyuki Okumura

Department of Social Psychiatry,

National Institute of Mental Health,

National Center of Neurology and Psychiatry

yokumura@blue.zero.jp

### References

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

### See Also

`ind.prop`

, `ind.prop.second`

### Examples

1 2 3 4 5 | ```
##Cohen (1988) ex.6.7
samplesize.h(delta=.20, power=.90, sig.level=.01)
##Cohen (1988) ex.6.8
samplesize.h(delta=.2828, power=.95, sig.level=.05)
``` |