Source-level hypothesis
Definition
A proposition about who or what produced a trace, for example 'this glass came from the broken window at the crime scene' versus 'this glass came from some other source'. Verbal LR scales must be read in the context of the hypothesis pair they address; the same verbal phrase may correspond to very different evidential weight at source level versus activity level.
Related terms
- ENFSI Guideline for Evaluative Reporting
- A consensus guidance document from the European Network of Forensic Science Institutes that defines how member laboratories should express evaluative opinions. It...
- Evaluative conclusion
- A forensic opinion that addresses the weight of the evidence, typically expressed as an LR or a verbal equivalent. Distinct from a...
- 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...
- UK Forensic Science Regulator (FSR)
- The statutory body in England and Wales responsible for setting and monitoring quality standards in forensic science. The FSR has published codes...
- Verbal scale
- The ENFSI translation of numerical likelihood ratios into courtroom language: very strong support (LR over 10,000), strong support (LR 1,000-10,000), moderate support...
Explained in
- Verbal Equivalents of the Likelihood RatioA proposition about who or what produced a trace, for example 'this glass came from the broken window at the crime scene' versus 'this glass came from some oth...