samplesize.r: Sample size estimation in the significance testing of a...

In rpsychi: Statistics for psychiatric research

Description

samplesize.r determines the sample size, when specified the effect size to be detected, desired statistical power, and significance level. samplesize.r always specifies two-sided test.

Usage

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

Arguments

delta	a numeric contains the effect size (product moment correlation) 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.

Author(s)

Yasuyuki Okumura
Department of Social Psychiatry,
National Institute of Mental Health,
National Center of Neurology and Psychiatry
[e-mail]

References

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

See Also

zero.r.test, zero.r.test.second

Examples

##Cohen (1988) ex.3.4
samplesize.r(delta=.3, power=.8, sig.level=.05)

rpsychi documentation built on May 1, 2019, 10:10 p.m.