GAMBLING WITH UNCERTAINTY

摘要

The ISO Guide to the Expression of Uncertainty in measurement (GUM) has been in use for more than a decade. During this time a number of articles pointing to possible deficiencies in both the philosophy and procedures of the GUM have appeared in such prestigious journals as Metrologia. In response, a Supplement is being prepared, giving guidance on using Monte Carlo methods as an alternative method of calculating both the measurand and the confidence interval. This paper describes the proposed method and discusses its application to the previously vexed issue of asymmetric uncertainties such as those that arise with instruments that truncate the measured value. This truncation occurs with many devices used in vehicle speed measurement, such as the RADAR and LIDAR "guns" and is a major part of the uncertainty associated with these instruments. The Monte Carlo approach neatly deals with this and other issues.