NCJ Number
145538
Journal
Journal of the Forensic Science Society Volume: 33 Issue: 3 Dated: (July-September 1993) Pages: 173-178
Date Published
1993
Length
6 pages
Annotation
A forensic scientist talks about the profession to lead to a distinction between unscientific and scientific expertise.
Abstract
The author discusses how computers and human perception contribute to pattern identification, how subjectivity can affect the assessment of probabilities, and how such logical fallacies as confusing odds with probabilities may come into play. For example, according to "the prosecutor's fallacy," 1-in-100 odds that blood stains at a crime scene were left by someone other than the suspect with the same blood type means 100-to-1 odds against someone else having left the stain. This is analogous to determining the probability that a die is loaded, based on the odds of throwing a particular number. Those not trained in forensic science may be excused for such illogic, but not forensic scientists, if they want to advance their profession as a scientific discipline. The ethos of unscientific expertise may be encapsulated as follows: 1) Mystique ("When you've been doing a job as long as I have..."); 2) Intuition ("I rely on my gut feeling..."); 3) Complacency ("I've done thousands of cases and never been shown to be wrong..."); and 4) Entrenchment ("It's stood the test of time..."). Conversely, the ethos of scientific expertise may be encapsulated as follows: 1) Study and debate ("What are our fundamental principles?"); 2) Continuous improvement ("Why do I do it this way? Is there a better way?"); 3) Self-analysis ("Why do I think this?"); and 4) Calibration ("Am I as good as I think I am?"). 8 references