ci.spear2 {statpsych}

Confidence interval for a 2-group Spearman correlation difference

Description

Computes a confidence interval for a difference in population Spearman correlations in a 2-group design.

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)

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