SPRT
SPRT stands for the Sequential Probability Ratio Test. It is a statistical method for testing two simple hypotheses by evaluating data as they arrive and stopping when evidence is strong enough to decide between the hypotheses. Introduced by Abraham Wald in 1947, the SPRT is designed to minimize the expected sample size for specified error rates under simple hypotheses.
Procedure: Let Λn denote the likelihood ratio based on the first n observations, Λn = f1(x1, ..., xn)
Properties: The stopping time is random, since sampling continues until the evidence crosses a boundary. Under
Extensions and applications: SPRT has variants for different data types, including Bernoulli, normal with known variance,