Optimized Group Sequential Study Designs for Tests of Genetic Linkage and Association in Complex Diseases  Inke R. König, Helmut Schäfer, Hans-Helge Müller, Andreas Ziegler  The American Journal of Human Genetics  Volume 69, Issue 3, Pages 590-600 (September 2001) DOI: 10.1086/323250 Copyright © 2001 The American Society of Human Genetics Terms and Conditions

Figure 1 Simulated average sample sizes for the one-sided mean test under H0 and H1. α=.0001, and β=.2; number of replications = 3,900,000 under H0 and 700,000 under H1. Gray line, simulated average sample sizes in the fixed-sample design. Solid and dotted black lines, simulated average sample sizes in the group sequential designs with two and three stages, respectively. The American Journal of Human Genetics 2001 69, 590-600DOI: (10.1086/323250) Copyright © 2001 The American Society of Human Genetics Terms and Conditions