Tippett plot
Definition
A calibration diagnostic plot that shows the cumulative distributions of LR values calculated for known same-source pairs and known different-source pairs. Well-calibrated systems show the two curves diverging strongly; overlapping curves indicate poor discrimination.
Related terms
- Between-source variation
- The variation observed among samples from different locations in the reference population. Used to estimate the probability of the observed similarity under...
- Denominator hypothesis
- The defence hypothesis under which the LR denominator is calculated. Typically: the questioned sample comes from some other location within the relevant...
- ENFSI verbal scale
- A standardised scale for communicating LR values to courts in plain language, ranging from 'limited support' (LR 1-10) through 'moderate,' 'moderately strong,'...
- Numerator hypothesis
- The prosecution hypothesis under which the LR numerator is calculated. In a source comparison it is typically: the questioned sample and the...
- Within-source variation
- The natural variation observed among multiple samples collected from a single source location. Used to estimate the probability of the observed difference...
Explained in
- Likelihood Ratios and Verbal Scales in Geological EvidenceA calibration diagnostic plot that shows the cumulative distributions of LR values calculated for known same-source pairs and known different-source pairs. Wel...