Sample size calculation: Correlation coefficient
Calculates the required sample size for a correlation coefficient. The sample size takes into account the required significance level and power of the test (see Sampling: Introduction).
For example, the correlation coefficient between two variables is thought to be 0.60. How many patients are required for this correlation coefficient to be significant different from 0.0?
For α-level you select 0.05 and for β-level you select 0.20 (power is 80%).
After you click the Calculate button the program displays the required sample size (19 in the example, meaning that you will need 19 cases in which both variables must be measured).
A table shows the required sample size for different Type I and Type II Error levels.