Log-LR (log likelihood ratio)
Definition
The natural or base-10 logarithm of the LR. Log-LRs are additive for independent evidence types, making them convenient for combining across disciplines. Positive log-LR supports Hp; negative supports Hd. Speaker comparison systems typically output log-LR scores directly.
Related terms
- Defence proposition (Hd)
- The alternative proposition, typically asserting that someone else is the source (e.g., 'the crime-scene DNA came from an unknown, unrelated person'). It...
- Kernel density estimate (KDE)
- A non-parametric smooth probability density function fitted to a set of measurements by placing a kernel (usually Gaussian) over each data point...
- 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...
- Prosecution proposition (Hp)
- The proposition advanced by the prosecution, typically asserting that the defendant is the source of the questioned material (e.g., 'the crime-scene DNA...
- Random match probability (RMP)
- The probability that a randomly chosen unrelated person from the relevant population would match the evidence profile by chance. A very small...
Explained in
- Computing Likelihood Ratios: Worked ExamplesThe natural or base-10 logarithm of the LR. Log-LRs are additive for independent evidence types, making them convenient for combining across disciplines. Posit...