Sample size for a Pearson or partial correlation confidence interval

Computes the sample size required to estimate a population Pearson or partial correlation with desired confidence interval precision. Set s = 0 for a Pearson correlation. Set the correlation planning value to the smallest absolute value within a plausible range for a conservatively large sample size.

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

Arguments

alpha

alpha level for 1-alpha confidence

cor

planning value of correlation

s

number of control variables

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.cor(.05, .362, 0, .25)
#>  Sample size
#>          188

# Should return:
# Sample size
#         188