NCJ Number
246869
Journal
Journal of Forensic Sciences Volume: 59 Issue: 3 Dated: May 2014 Pages: 811-815
Date Published
May 2014
Length
5 pages
Annotation
Proper interpretation of forensic measurements can be critical to the administration of justice.
Abstract
Proper interpretation of forensic measurements can be critical to the administration of justice. Breath alcohol testing is commonly relied upon to measure the concentration of alcohol in breath or, indirectly, in blood. The concentration sought constitutes the quantity intended to be measured, referred to as the measurand. Although breath tests always probe the same physical quantity, their measurand is dictated by statute and varies between jurisdictions. Thus, identical numerical values obtained from tests in disparate jurisdictions may refer to different quantities and may not indicate the relevant statutory measurand. This can lead to misinterpretation of results, referred to as the measurand problem. We first illustrate the concept of the measurand. Thereafter, the measurand problem is illustrated through application of Hlastala's breath test paradigm and Gullberg's work on breath test uncertainty. It is shown that where the measurand is not properly accounted for, conclusions based upon breath test evidence are undermined. Abstract published by arrangement with Wiley.