The author's argument depends on which assumption?
Forensic experts often describe their evidence in terms that sound conclusive: a fingerprint 'matches', a bite mark is 'consistent with' the defendant's teeth. Juries are impressed by such language, and for good reason, since the evidence is presented as science. But a match is a judgement made by a person comparing two marks, and its reliability depends on how often examiners agree with one another and with the truth. Where studies of these error rates have been done, they have sometimes shown that a technique long treated as near-infallible makes mistakes at a rate that would surprise a jury. The proper response is not to ban forensic evidence but to require experts to state error rates and to qualify their claims accordingly.
Answer and explanation
Correct answer: A. That jurors will weigh evidence differently if they are told how often the technique errs
- Step 1: The recommendation of stating error rates only makes sense if the information would change how jurors respond.
- Step 2: The author assumes it would.
Answer
That jurors will weigh evidence differently if they are told how often the technique errs.
Why not the others: The author does not assume dishonesty, says error rates can be measured and offers no ranking of techniques.
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