Bernoulli Trials With Skewed Propensities for Certification and Validation

Abstract

The impetus for writing this paper are the well publicized media reports that software failure was the cause of the two recent mishaps of the Boeing 737 Max aircraft. The problem considered here though, is a specific one, in the sense that it endeavors to address the general matter of conditions under which an item such as a drug, a material specimen, or a complex, system can be certified for use based on a large number of Bernoulli trials, all successful. More broadly, the paper is an attempt to answer the old and honorable philosophical question, namely," when can empirical testing on its own validate a law of nature?" Our message is that the answer depends on what one starts with, namely, what is one's prior distribution, what unknown does this prior distribution endow, and what has been observed as data. The paper is expository in that it begins with a historical overview, and ends with some new ideas and proposals for addressing the question posed. In the sequel, it also articulates on Popper's notion of "propensity" and its role in providing a proper framework for Bayesian inference under Bernoulli trials, as well as the need to engage with posterior distributions that are subjectively specified; that is, without a recourse to the usual Bayesian prior to posterior iteration.