A 2-STAGE ADAPTIVE GROUP-TESTING PROCEDURE FOR ESTIMATING SMALL PROPORTIONS

A method for adaptively estimating a proportion p using group-testing procedures is presented and analyzed, with emphasis placed on a two-stage procedure. This estimator is compared to the usual group-testing estimator via asymptotic and small-sample relative efficiency. The adaptive estimator is generally recommended with the restriction that adaptations (i.e., adjustments of group size) are based on at least 10 measurements/responses. But if one is confident that one has a ''very good'' a priori estimate of p, then the usual estimator is recommended. Monte Carlo simulations show that a normal approximation is adequate for generating confidence intervals with confidence coefficients as high as .95.