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statpsych (version 1.7.0)

size.ci.spear2: Sample size for a 2-group Spearman correlation difference confidence interval

Description

Computes the sample size required to estimate a difference in population Spearman correlations with desired confidence interval precision in a 2-group design. Set the correlation planning values to the smallest absolute values within their plausible ranges for a conservatively large sample size.

Usage

size.ci.spear2(alpha, cor1, cor2, w)

Value

Returns the required sample size

Arguments

alpha

alpha level for 1-alpha confidence

cor1

group 1 Spearman correlation planning value

cor2

group 2 Spearman correlation planning value

w

desired confidence interval width

References

Bonett2000statpsych

Examples

Run this code
size.ci.spear2(.05, .8, .5, .2)

# Should return:
# Sample size per group
#                   314
 

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