Most statistical work builds on a well-established paradigm. Abraham Wald fully developed and established a new paradigm based on sequential tests of statistical hypotheses. Although formulated in 1943, the new paradigm was first published as “Sequential Tests of Statistical Hypotheses” in The Annals of Mathematical Statistics in 1945. In traditional statistical hypothesis testing, an experiment is performed using a predetermined sample size chosen to ensure sufficient statistical power so the null hypothesis is likely to be rejected when in truth it should be rejected. In sequential hypothesis testing, experiments are designed so that after each observation, a decision could be made to accept or reject the null hypothesis or to gather another [Page 1352]observation. Thus, a final decision would be based on a sequence of ...