Sample size for a Spearman correlation confidence interval

Computes the sample size required to estimate a population Spearman correlation with desired confidence interval precision. Set the correlation planning value to the smallest absolute value within a plausible range for a conservatively large sample size.

Usage

size.ci.spear(alpha, cor, w)

Arguments

alpha

alpha level for 1-alpha confidence

cor

planning value of Spearman correlation

w

desired confidence interval width

Value

Returns the required sample size

References

Bonett DG, Wright TA (2000). “Sample size requirements for estimating Pearson, Kendall and Spearman correlations.” Psychometrika, 65(1), 23–28. ISSN 0033-3123, doi:10.1007/BF02294183 .

Examples

size.ci.spear(.05, .362, .25)
#>  Sample size
#>          200

# Should return:
# Sample size
#         200