Annals of Occupational Hygiene Advance Access originally published online on June 5, 2008
Annals of Occupational Hygiene 2008 52(6):519-525; doi:10.1093/annhyg/men023
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
The Meaning of the Bias Uncertainty Measure
3904 Pocahontas Avenue, Cincinnati, OH 45227, USA
* Author to whom correspondence should be addressed. Tel: +1 513 652 4949; e-mail: dbartley{at}eos.net
Characterization of measurement uncertainty in terms of root sums of squares of both unknown systematic as well as random error components is given meaning in the sense of prediction intervals. Both types of errors are commonly encountered with industrial hygiene air monitoring of hazardous substances. Two extreme types of measurement methods are presented for illustrating how confidence levels may be ascribed to prediction intervals defined by such uncertainty values. In the case of method calibration at each measurement, systematic error or bias may enter from a biased calibrant. At another extreme, a single initial method evaluation may leave residual bias owing to random error in the evaluation itself or to the use of a biased reference method. Analysis is simplified through new simple approximations to probabilistic limits (quantiles) on the magnitude of a non-central Student t-distributed random variable. Connection is established between traditional confidence limits, accuracy measures in the case of bias minimization and an uncertainty measure.
Keywords: bias systematic error uncertainty accuracy non-central Student's t
Received February 24, 2008; in final form April 14, 2008
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
D. Bartley and G. Liden Measurement Uncertainty Ann. Hyg., August 1, 2008; 52(6): 413 - 417. [Abstract] [Full Text] [PDF] |
||||
