Sample size determination for constructing a constant width confidence interval for a binomial success probability

This article determines the sample size required to construct a confidence interval for the success probability of an event with preassigned width 2d and confidence level 1 - alpha. For alpha = 0.10, 0.05, 0.01 and d = 0.0 1 (0.01)0.05, the sample size is tabulated and the corresponding confidence interval defined. For other values of alpha and d, Fortran 77 programs are available from the authors. (C) 2002 Elsevier Science B.V. All rights reserved.