Confidence curves and improved exact confidence intervals for discrete distributions

The author describes a method for improving standard exact confidence intervals in discrete distributions with respect to size while retaining correct level. The binomial, negative binomial, hypergeometric, and Poisson distributions are considered explicitly. Contrary to other existing methods, the author's solution possesses a natural nesting condition: if alpha < ', the 1 - alpha' confidence interval is included in the 1 - alpha interval. Nonparametric confidence intervals for a quantile are also considered.