Theory 084/Law & Forensic Science
Glass Matching Is Overlap
The claim
Forensic glass matching discriminative power is set by the overlap of refractive index distributions rather than by absolute index difference.
01The mechanism
Two sources are distinguishable only where their distributions separate; a large difference with wide spreads is less useful than a small one with narrow spreads.
02Predictions
- P1Discrimination should track overlap.
- P2Absolute difference alone should mispredict.
03Refutation
Discrimination tracking absolute difference would remove the spread term.