How to Gauge Unknown Unknowns: A Possible Theoretical Explanation of the Usual Safety Factor of 2

Authors

Joe Lorkowski, The University of Texas at El PasoFollow
Vladik Kreinovich, The University of Texas at El PasoFollow

Publication Date

10-2014

Comments

Technical Report: UTEP-CS-14-68

Published in Mathematical Structures and Modeling, 2014, Vol. 32, pp. 49-52.

Abstract

To gauge the accuracy of a measuring instrument, engineers analyze possible factors contributing to the instrument's inaccuracy. In addition to known factors, however, there are usually unknown factors which also contribute to the instrument's inaccuracy. To properly gauge the instrument's accuracy -- and thus, to make sure that we do not compromise our safety by underestimating the inaccuracy -- we need to also take these "unknown unknowns" into account. In practice, this is usually done by multiplying the original estimate for inaccuracy by a "safety" factor of 2. In this paper, we provide a possible theoretical explanation for this empirical factor.