Originally posted by Lewis C
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Yes. I still haven't gone over the paper in detail, and I may have made an error in my post above where I stated the ranges as +- half the amount. Rereading what I wrong, I shouldn't have halved things, so basically, if someone is actually 30, then less than half of the people will guess an age between 20 and 40! (less than half are within 10 years of the true age, so one would apply that error range to the guess as well). However, I'm sure the data is a bit more complicated, and the +- won't be equal in both directions for all guesses. Meaning, if someone estimated an age of 20, it's unlikely the true age is 10 years less than that, so the lower end probably bunches up as the estimates get younger. I'm being a bit pedantic here, but thought I would mention it all the same.
Anyway, I think most of the estimated ages we get from the witnesses are around 30, so an age range of something like 20 to 40 would probably be correct with about 47% probability, meaning - age estimates are pretty useless really. Even Long's estimate of 40 means the person she saw could be in their 20's with a reasonable probability. In the end, I wouldn't put much effort into worrying about how well a suspect's age corresponds to any of the estimates.
And heights and weights are pretty poorly estimated as well, and that gets worse when subjective descriptors are used (short, tall, stocky, stout, lanky, medium build, etc). All of the descriptions about the individual are probably consistent with someone of relatively "average" appearance, keeping in mind that "average" spans a great deal of different actual measurements.
What might be of more use, though I'm not sure of how reliable these sorts of descriptions are at the moment, might come from descriptions of the man's height relative to the victim. But even in the few cases we have of those I think it's subjective ("a little taller", etc), so again, those might appear more informative than they actually are.
Really, the take home message is that the details of the men described by the eye-witnesses are not as useful as they might "feel" to us. Our understanding of what constitutes "short" or "tall" and so forth is unlikely the same as what the eye-witness considered to be "short" or "tall", etc. So just because a suspect is known to be 5'6", for example, and someone describes the man they saw as being "tall" doesn't amount to information upon which you can say "Can't be him." Well, of course you can say that, but there's no objective reason for anyone to take you seriously.
- Jeff
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