Skip to contents

Confidence interval for a 2-group Spearman correlation difference

Source: R/statpsych2.R
ci.spear2.Rd

Computes a confidence interval for a difference of population Spearman correlations in a 2-group design. This function is not appropropriate for ordered categorical variables.

Usage

ci.spear2(alpha, cor1, cor2, n1, n2)

Arguments

alpha

alpha level for 1-alpha confidence

cor1

estimated Spearman correlation for group 1

cor2

estimated Spearman correlation for group 2

n1

sample size for group 1

n2

sample size for group 2

Value

Returns a 1-row matrix. The columns are:

  • Estimate - estimated correlation difference

  • SE - standard error

  • LL - lower limit of the confidence interval

  • UL - upper limit of the confidence interval

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 .

Zou GY (2007). “Toward using confidence intervals to compare correlations.” Psychological Methods, 12(4), 399–413. ISSN 1939-1463, doi:10.1037/1082-989X.12.4.399 .

Examples

ci.spear2(.05, .54, .48, 180, 200)
#>  Estimate         SE         LL        UL
#>      0.06 0.08124926 -0.1003977 0.2185085

# Should return:
# Estimate         SE         LL        UL
#     0.06 0.08124926 -0.1003977 0.2185085