Radio Show on Fingerprint Error and Cognition

[charlton97]

All in the Mind
16/11/2010
16/11/2010
LISTEN:
Next On:
Next Tuesday, 21:00 on BBC Radio 4
SYNOPSIS
When the Oregon attorney, Brandon Mayfield, was arrested for the Madrid bombing six years ago, the FBI's fingerprint examiners claimed they were 100% sure that his fingerprints were on the bag containing detonators and explosives. But they were wrong. And this sensational error has drawn attention ever since, to the widely held, but erroneous belief, that fingerprint identification is infallible.
Cognitive psychologists and neuroscientists have challenged forensic science as a whole to raise its game; and acknowledge that errors in fingerprinting and other forensic disciplines are inevitable because of the architecture of cognition and the way our brains process information. Experts say that it's not a case of will an error occur, but when.
Claudia Hammond investigates the evidence that forensic examiners are making mistakes simply because they're human, and asks what safeguards are in place to limit the potentially lifethreatening impact of forensic error.
Producer: Fiona Hill.

BROADCAST
Tue 16 Nov 201021:00
BBC Radio 4

[L.J.Steele]

For more bending your brain research, in this case on choices and rationalizations. It isn't directly relevant to fingerprint examination, except in showing how our brain can construct a rationale for any decision, even one opposite from an initial choice.

http://sites.google.com/site/lucswiki/p ... -blindness

The basic idea underlying choice blindness research is to use false feedback as an instrument to study intentions, self-knowledge and preference formation in decision making. For example, in Johansson et al. (2005), the participants were shown pairs of pictures of female faces, and were given the task of choosing which face in each pair they found most attractive. In addition, on some trials, immediately after their choice, they were asked to verbally describe the reasons for choosing the way they did. Unknown to the participants, on certain trials, a double-card ploy was used to covertly exchange one face for the other. Thus, on these trials, the outcome of the choice became the opposite of what they intended (see video link below). From a common sense perspective it would seem that everyone immediately would notice such a radical change in the outcome of a choice. But that was not the case. The result showed that in the great majority of trials our participants were blind to the mismatch between choice and outcome, while nevertheless being prepared to offer introspectively derived reasons for why they chose the way they did.

Here's a video clip demonstrating the experiment:
http://www.youtube.com/watch?v=wRqyw-Ew ... re=related

Choice blindness is a robust, replicable, and often dramatic effect (not only baffling to many participants, but to the researchers themselves). As described above, we have established it for male and female faces as well as abstract patterns, both when the alternatives are presented on a computer screen and when presented ‘by hand’. We have also demonstrated choice blindness for the taste of jam and the smell of tea in an ecologically valid supermarket setting. In this experiment, we set up a sample stand at a local supermarket, where we invited customers to participate in a blind test of two paired varieties of jam and tea. The results were similar to our experiments with faces, as very few participants detected the changes we made (even for such remarkably different tastes as spicy Cinnamon­-Apple and bitter Grapefruit, or for the sweet taste of Mango and pungent Pernod less than half of all manipulation trials were detected)

Here's two video clips demonstrating the experiment:
http://www.youtube.com/watch?v=_VPcl04Adh8
http://www.youtube.com/watch?v=58Lrzn7P0h8

[Michele]

Lisa,

I find this interesting. It shows that when people make decisions based on feelings and using a self-imposed threshold requirement then conclusions can change from moment to moment. Conclusions can change from moment to moment since people’s feelings can change from moment to moment.

This is why scientific conclusions offer conclusions that are more stable. Scientific conclusions are based on data (not feelings), the use of accepted principles, and a threshold of acceptability.

(Regarding the radio show Dave mentioned) With the Mayfield error, the independent expert stated that he was aware of how to properly conduct a comparison (he should have been attempting to refute the conclusion and not confirm it) but he was in a hurry and didn’t follow the appropriate principles. (It’s been a long time since I saw this presentation so feel free to point out if I’m portraying this inaccurately).

The information posted is interesting but it seems to be outside the realm of what examiners should be doing. I’m not trying to imply that LPE’s don’t make errors but isn’t it more beneficial to improve procedures (or improve training on appropriate procedures) to reduce errors rather than keep comparing examiners to those that make decisions based on emotions instead of looking at situations where people make decisions based on objective data?