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statpsych (version 1.7.0)

size.equiv.prop.ps: Sample size for a paired-samples proportion equivalence test

Description

Computes the sample size required to perform an equivalence test for the difference in population proportions with desired power in a paired-samples design. The value of h specifies a range of practical equivalence, -h to h, for the difference in population proportions. The absolute difference in the proportion planning values must be less than h. Equivalence tests often require a very large sample size. Equivalence tests usually use 2 x alpha rather than alpha (e.g., use alpha = .10 rather alpha = .05). This function sets the effect size equal to the difference in proportion planning values. Set the phi correlation planning value to the smallest value within a plausible range for a conservatively large sample size.

Usage

size.equiv.prop.ps(alpha, pow, p1, p2, phi, h)

Value

Returns the required sample size

Arguments

alpha

alpha level for hypothesis test

pow

desired power

p1

planning value of proportion for measurement 1

p2

planning value of proportion for measurement 2

phi

planning value of phi correlation

h

upper limit for range of practical equivalence

Examples

Run this code
size.equiv.prop.ps(.1, .8, .30, .35, .40, .15)

# Should return:
# Sample size
#         173


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