Sequential Analysis

Sequential analysis refers to a statistical method in which data are evaluated as they are collected, and further sampling is stopped in accordance with a predefined stopping rule as soon as significant results are observed. This contrasts to classical hypothesis testing where the sample size is fixed in advance. On average, sequential analysis will lead to a smaller average sample size compared with an equivalently powered study with a fixed sample size design and, consequently, lower financial and/or human cost.

Sequential analysis methods were first used in the context of industrial quality control in the late 1920s. The intensive development and application of sequential methods in statistics was due to the work of Abraham Wald around 1945. Essentially, the same approach was independently developed by George ...