Sample size for a slope confidence interval in a general statistical model

Computes the sample size required to estimate a slope coefficient with desired confidence interval precision in any type of statistical model. This function requires a standard error estimate for the slope of interest from a prior or pilot study and the sample size that was used in the prior or pilot study. This function can be used for both unstandardized and standardized slopes. This function also can be used for both unstandardized and standardized factor loadings in a confirmatory factor analysis model. This function will soon be replaced with size.ci.gen.

Usage

size.ci.slope.gen(alpha, se, n0, w)

Arguments

alpha

alpha level for 1-alpha confidence

se

standard error of slope from prior/pilot study

n0

sample size used in prior/pilot study

w

desired confidence interval width

Value

Returns the required sample size

Examples

size.ci.slope.gen(.05, 3.15, 50, 5)
#>  Sample size
#>          305

# Should return:
#  Sample size
#          305