samplesize.h: Sample size estimation in the differences between proportions

Description Usage Arguments Value Author(s) References See Also Examples

View source: R/samplesize.h.R

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

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

Arguments

delta

a numeric contains the effect size (Cohen's h) to be detected

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

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##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)

rpsychi documentation built on May 29, 2017, 12:57 p.m.