Identification (SWGDOC)
Definition
The most positive conclusion on the SWGDOC scale, meaning the examiner has found individualising agreement in all significant habitual writing characteristics, with no significant unexplained differences, sufficient to conclude common authorship.
- Scale position
- Highest conclusion on the SWGDOC nine-point scale
- Basis
- Agreement in all significant habitual writing characteristics
- Requirement
- No significant unexplained differences present
- Scale author
- Scientific Working Group for Forensic Document Examination
- Contrast
- ENFSI uses a numeric likelihood-ratio scale instead
Common questions
Does an Identification conclusion mean the writer is proven with mathematical certainty?+
No. It is a categorical opinion, not a statistical one. It reflects the examiner's judgment that the combination of matching features is sufficient and individualising, but SWGDOC does not attach a numeric probability to it, which is one reason ENFSI-style likelihood-ratio scales have gained ground.
How is Identification different from the next step down, such as Highly Probable?+
Identification requires no significant unexplained differences at all. A step below allows some unexplained variation that the examiner judges minor, reflecting lower confidence that the same writer produced both samples.
Related terms
- Courtroom-Language Translation Problem
- The empirically documented gap between what forensic verbal conclusion terms (such as 'strong probability') are intended to convey by examiners and what...
- Elimination (SWGDOC)
- The most definitive negative conclusion on the SWGDOC scale, meaning fundamental differences in writing habits that cannot be attributed to disguise, natural...
- ENFSI Evaluative Standard
- The European Network of Forensic Science Institutes 'Standard for Formulation of Evaluative Forensic Science Expert Opinions' (2015/2016), which requires examiners to reason...
- Foundational Validity as Applied
- PCAST's standard requiring that a forensic discipline be validated through black-box studies measuring real-examiner error rates under realistic conditions, not just laboratory...
- Likelihood Ratio (LR)
- The ratio of two conditional probabilities: the probability of the observed evidence given the prosecution's hypothesis (same source), divided by the probability...
- No Conclusion (SWGDOC Position 5)
- The midpoint of the SWGDOC scale, indicating that the evidence is equally consistent with a common source or different sources. It is...
- PCAST 2016 Report
- The President's Council of Advisors on Science and Technology 2016 report 'Forensic Science in Criminal Courts: Ensuring Scientific Validity of Feature-Comparison Methods,'...
- Population-Frequency Anchoring
- The practice of grounding a conclusion about feature rarity in empirically measured frequency data for those features in the relevant writing population,...
- SWGDOC Nine-Point Scale
- The conclusion scale developed by the Scientific Working Group for Forensic Document Examination, running from 'identification' (most positive) through 'no conclusion' (midpoint)...