A TABLE OF EXACT SAMPLE SIZES FOR USE WITH FISHER EXACT TEST FOR 2X2 TABLES

We studied systematically the problem of sample size for Fisher's exact test of independence in 2 X 2 tables, assuming that neither of the two margins is fixed. In this case, we present tables to calculate sample sizes necessary to achieve 50% and 90% power with the significance level equal to 1% or 5%. These tables can be used to determine the sample size necessary to detect gametic-phase disequilibrium between two genetic loci in a population genetics survey. A one-sided test and two double-sided tests are considered corresponding to the two most commonly used interpretations of observed significance.