samplesize4surveys (version 4.1.1)

b4dp: Statistical power for a hyphotesis testing on a difference of proportions

Description

This function computes the power for a (right tail) test of difference of proportions.

Usage

b4dp(N, n, P1, P2, D, DEFF = 1, conf = 0.95, plot = FALSE)

Arguments

N

The population size.

n

The sample size.

P1

The value of the first estimated proportion.

P2

The value of the second estimated proportion.

D

The value of the null effect.

DEFF

The design effect of the sample design. By default DEFF = 1, which corresponds to a simple random sampling design.

conf

The statistical confidence. By default conf = 0.95.

plot

Optionally plot the power achieved for an specific sample size.

Value

The power of the test.

Details

We note that the power is defined as: $$1-\Phi(Z_{1-\alpha} - \frac{(D - (P_1 - P_2))}{\sqrt{\frac{DEFF}{n}(1-\frac{n}{N})(P_1Q_1+P_2Q_2)}})$$

References

Gutierrez, H. A. (2009), Estrategias de muestreo: Diseno de encuestas y estimacion de parametros. Editorial Universidad Santo Tomas

See Also

ss4p

Examples

# NOT RUN {
b4dp(N = 100000, n = 400, P1 = 0.5, P2 = 0.5, D = 0.03)
b4dp(N = 100000, n = 400, P1 = 0.5, P2 = 0.5, D = 0.03, plot = TRUE)
b4dp(N = 100000, n = 4000, P1 = 0.5, P2 = 0.5, D = 0.05, DEFF = 2, conf = 0.99, plot = TRUE)
# }