OSAC 2022/0004
Definition
The OSAC Standard for Friction Ridge Examination Conclusions (2023), specifying a graduated five-level conclusion vocabulary, prohibiting zero-error-rate language, and requiring that examiners contextualise error rates with reference to the empirical literature when asked.
- Full name
- OSAC Standard for Friction Ridge Examination Conclusions
- Published
- 2023
- Conclusion scale
- Graduated five-level vocabulary
- Prohibits
- Zero-error-rate language
- Related context
- Response to 2009 NAS critique of fingerprint identification
Common questions
Why does the standard prohibit examiners from claiming a zero error rate?+
Empirical proficiency testing has shown that fingerprint examination, like other pattern comparison disciplines, has a measurable non-zero error rate, and claiming absolute certainty overstates the science. The standard instead requires examiners to speak to the graduated conclusion scale and, when asked, reference the actual empirical error rate literature rather than asserting infallibility.
How does a graduated five-level conclusion scale differ from the traditional identification/exclusion/inconclusive framework?+
The traditional framework treated identification as a binary, all-or-nothing conclusion, while a graduated scale allows examiners to express varying degrees of support for a match, similar to how DNA evidence is reported with likelihood ratios, giving fact-finders a more calibrated sense of the strength of the association rather than an overstated certainty.
Related terms
- Black-Box Study
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- CrimPR Part 19
- Criminal Procedure Rules Part 19 (England and Wales): the expert-witness procedural code requiring disclosure of qualifications, methodology, limitations, and whether the method...
- Daubert Standard
- The US federal evidentiary standard (Daubert v. Merrell Dow Pharmaceuticals, 1993) requiring that expert testimony be based on scientifically valid methods with...
- Evaluative Reporting
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- False-Positive Rate
- The proportion of authentic media files that a detection tool incorrectly classifies as manipulated or synthetic. Deepfake detectors and ELA tools both...
- Individualization
- The forensic claim that a friction-ridge mark was made by one specific person to the exclusion of all others; the categorical form...
- NAS 2009 Report
- The National Academy of Sciences report 'Strengthening Forensic Science in the United States: A Path Forward' (2009), which critiqued the scientific foundations...
- Ulery 2011 Study
- Ulery et al. (2011), 'Accuracy and reliability of forensic latent fingerprint decisions,' PNAS 108(19): 7733-7738; the largest empirical black-box study of fingerprint...