lamme (version 0.0.1)

ss.lancova: Sample Size Planning for LANCOVA

Description

Compute the required per-group sample size for the LANCOVA test.

Usage

ss.lancova(k, rho_sqrd, r_sqrd, power = 0.8, alpha = 0.05)

Arguments

k

the number of groups.

rho_sqrd

the pretest-posttest correlation

r_sqrd

the expected explained variance by the model (on the logged scale)

power

the desired statistical power (default=.8)

alpha

the significance level (default=.05)

Value

n

the per-group sample size requirement

References

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

Examples

# NOT RUN {
ss.lancova(3,.5,.01,.14,.05)
# }