Review of concepts relating to measurement quality

Misconceptions about measurements and measurement quality persist even among otherwise highly competent acoustical and noise-control professionals. There are many related but different concepts to describe measurement quality, including precision, accuracy, bias, uncertainty, resolution, and significant figures. These concepts apply to reporting a measurement result, to characterization of test methods, to evaluation against a specification, and to criteria for development of both test methods and specifications. The field of acoustics and noise control attracts professionals with a broad range of backgrounds, and therefore not all are versed in exactly what a measurement result means, or the difference in these measurement quality concepts. This is further compounded by the fact that many times acoustic tests are used in legal contexts, either for code compliance or in legal disputes. The law wants to work with black-and-white concepts, but all measurements inherently have some grey areas. Proper understanding begins by acknowledging that the answer yielded by a measurement is not the correct answer, not the true value of the measurand, but something close to it (very close if high quality). The various concepts of measurement quality are all ways to assess the test method and the results yielded from the test method.