Exact Sample Sizes for Use with the Fisher-Irwin Test for 2 x 2 Tables
- 1 March 1978
- journal article
- research article
- Published by JSTOR in Biometrics
- Vol. 34 (1) , 106-109
- https://doi.org/10.2307/2529595
Abstract
Gail and Gart (1973) present tables showing the required sample size, n, for the Fisher-Irwin exact conditional test for 2 .times. 2 tables to achieve a power of at least 0.50, 0.80 and 0.90 against 1-sided alternatives at the nominal 0.05 and 0.01 significance levels. Calculations for n > 35 were based on the Arc sine approximation, which apparently underestimated the actual required sample size by as much as 34%. The purpose of this note is to revise Gail-Gart tables, giving exact sample sizes in all cases. The problem of nominal vs. actual significance levels when underlying probability of response is low is also briefly discussed.This publication has 2 references indexed in Scilit:
- STATISTICAL METHODS IN MEDICAL RESEARCH II. SAMPLE SIZES REQUIRED IN EXPERIMENTS INVOLVING ALL-OR-NONE RESPONSESCanadian Journal of Medical Sciences, 1953
- The Logic of Inductive InferenceJournal of the Royal Statistical Society, 1935