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Reliability of measurement uncertainty estimates for forensic analyses: evidence from recent proficiency tests

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Abstract

The ability of forensic laboratories to reliably estimate the uncertainty of their reported results is assessed by means of data from recent proficiency tests in which participants reported both their results and the associated uncertainties. Topics covered include the determination of blood alcohol, breath alcohol, and controlled substances—services commonly provided by forensic laboratories. It is seen that a statistically significant number of laboratories underestimate their own uncertainties, based on the incidence of the laboratories’ own reported coverage intervals failing to include the participant mean or assigned concentration of the test material.

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References

  1. Youden WJ (1972) Technometrics 14:1–11 (reprint of 1968 presentation)

    Article  Google Scholar 

  2. Horwitz W, Albert A (1997) Analyst 122:615–617

    Article  CAS  Google Scholar 

  3. Horwitz W (2003) J AOAC Int 86:109–111

    CAS  Google Scholar 

  4. Horwitz W (1998) J AOAC Int 81:785–794

    CAS  Google Scholar 

  5. Thompson M, Ellison SLR (2011) Accred Qual Assur 16:483–487. doi:10.1007/s00769-011-0803-0

    Article  Google Scholar 

  6. http://www.ctsforensics.com/reports/main.aspx. Visited 2 Dec 2015

  7. ISO 13528:2015(E) Statistical methods for use in proficiency testing by interlaboratory comparison. International Organization for Standardization, Geneva, Switzerland

  8. Ellison SLR, Mathieson K (2008) Performance of uncertainty evaluation strategies in a food proficiency scheme. Accred Qual Assur 13:231–238. doi:10.1007/s00769-007-0353-7

    Article  CAS  Google Scholar 

  9. Wernimont GT, Spendley W (1985) Use of statistics to develop and evaluate analytical methods. Arlington, Association of Official Analytical Chemists, p 11

    Google Scholar 

  10. Wallace JR (2010) Proficiency testing as a basis for estimating uncertainty of measurement: application to forensic alcohol and toxicology quantitations. J Forensic Sci 55:767–773. doi:10.1111/j.1556-4029.2010.01344.x

    Article  CAS  Google Scholar 

  11. ISO 21748:2010 Guidance for the Use of Repeatability, Reproducibility and Trueness Estimates in Measurement Uncertainty Estimation. International Organization for Standardization (ISO), Geneva, Switzerland

  12. Ellison SLR, Williamson A (eds) (2012) Eurachem/Citac guide: Quantifying uncertainty in analytical measurement, 3rd edn. www.eurachem.org

  13. ISO 5725-3:1994 Accuracy (trueness and precision) of measurement methods and results, part 3. International Organization for Standardization. Geneva, Switzerland

  14. Joint Committee for Guides in Metrology (2008) Guide to the expression of uncertainty in measurement JCGM 100:2008, section 3.4.2

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Acknowledgments

The author wishes to thank CTS for providing their report in electronic format, without which this effort would have been greatly extended, and especially his wife for her encouragement and patience.

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  1. 157 Ford Ave, Ventura, CA, USA

    Jack Wallace

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  1. Jack Wallace
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Correspondence to Jack Wallace.

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The opinions in this report should not be taken as the official position of the author’s employer, or of any organization to which the author belongs.

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Wallace, J. Reliability of measurement uncertainty estimates for forensic analyses: evidence from recent proficiency tests. Accred Qual Assur 21, 211–219 (2016). https://doi.org/10.1007/s00769-016-1211-2

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  • DOI: https://doi.org/10.1007/s00769-016-1211-2

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