size.prop {seqtest} | R Documentation |
Sample size determination for testing the proportion
Description
This function performs sample size computation for the one-sample and two-sample test for proportions based on precision requirements (i.e., type-I-risk, type-II-risk and an effect size).
Usage
size.prop(pi = NULL, delta, sample = c("two.sample", "one.sample"),
alternative = c("two.sided", "less", "greater"),
alpha = 0.05, beta = 0.1, correct = FALSE, output = TRUE)
Arguments
pi |
a number indicating the true value of the probability under the null hypothesis (one-sample test), |
delta |
minimum difference to be detected, |
sample |
a character string specifying one- or two-sample proportion test, must be one of "two.sample" (default) or "one.sample". |
alternative |
a character string specifying the alternative hypothesis, must be one of "two.sided" (default), "less" or "greater". |
alpha |
type-I-risk, |
beta |
type-II-risk, |
correct |
a logical indicating whether continuity correction should be applied. |
output |
logical: if |
Value
Returns an object of class size
with following entries:
call | function call |
type | type of the test (i.e., proportion) |
spec | specification of function arguments |
res | list with the result, i.e., optimal sample size |
Author(s)
Takuya Yanagida takuya.yanagida@univie.ac.at,
References
Fleiss, J. L., Levin, B., & Paik, M. C. (2003). Statistical methods for rates and proportions (3rd ed.). New York: John Wiley & Sons.
Rasch, D., Kubinger, K. D., & Yanagida, T. (2011). Statistics in psychology - Using R and SPSS. New York: John Wiley & Sons.
Rasch, D., Pilz, J., Verdooren, L. R., & Gebhardt, G. (2011). Optimal experimental design with R. Boca Raton: Chapman & Hall/CRC.
See Also
seqtest.prop
, size.mean
, size.cor
, print.size
Examples
#--------------------------------------
# Two-sided one-sample test
# H0: pi = 0.5, H1: pi != 0.5
# alpha = 0.05, beta = 0.2, delta = 0.2
size.prop(pi = 0.5, delta = 0.2, sample = "one.sample",
alternative = "two.sided", alpha = 0.05, beta = 0.2)
#--------------------------------------
# One-sided one-sample test
# H0: pi <= 0.5, H1: pi > 0.5
# alpha = 0.05, beta = 0.2, delta = 0.2
size.prop(pi = 0.5, delta = 0.2, sample = "one.sample",
alternative = "less", alpha = 0.05, beta = 0.2)
#--------------------------------------
# Two-sided two-sample test
# H0: pi.1 = pi.2 = 0.5, H1: pi.1 != pi.2
# alpha = 0.01, beta = 0.1, delta = 0.2
size.prop(pi = 0.5, delta = 0.2, sample = "two.sample",
alternative = "two.sided", alpha = 0.01, beta = 0.1)
#--------------------------------------
# One-sided two-sample test
# H0: pi.1 <= pi.1 = 0.5, H1: pi.1 > pi.2
# alpha = 0.01, beta = 0.1, delta = 0.2
size.prop(pi = 0.5, delta = 0.2, sample = "two.sample",
alternative = "greater", alpha = 0.01, beta = 0.1)