Two-stage plans for the testing of binomial parameters.

Two-stage plans, a middle course between fixed-sample-size plans and sequential plans, are a worthwhile tool. Attention is given to the testing of binomial parameters in two-stage plans. Tables are given for testing pi = 0.5 in one population, the sign-test situation. An example demonstrates how these tables can be used for testing the equality of the binomial parameters in two populations as well. Results of the two-stage plans are compared with fixed-sample-size plans, sequential plans, and other published results.