Prosopagnosia - why face-based password schemes won't work for all.
I'm frequently here blogging about biometrics and accessibility - too many biometric methods get confused when you don't have the credential. Aniridia means you don't have an iris, a lack of thumbs (congenital or accident-induced) means you don't have a thumbprint.
Here's another biometric that's going to cause problems, and I may have blogged about it before - prosopagnosia. Yeah, it's a long word, and difficult to type, so I'll use the common abbreviation, "proso".
I have a relatively mild, but noticeable, case of proso. I'll tell a little story about myself, but first there's a great, short, article in yesterday's Boston Globe. Read it - I'll wait.
Okay, so here's the story of the Starbucks Trinity.
Back when I was a stay-at-home dad, I would frequently trip off to Starbucks, for a drink and a chat, and to work on my laptop away from the Internet and phones.
One of the barristas there was studying Networking at the local college, so I'd chat with her every now and again, but her behaviour confused me - about two times out of three, she'd look at me like I was talking Greek.
After several weeks of this behaviour, I found out why - of course, you've guessed by now - they were three different women, each of different heights, weights, and hair colours. But because they all had long hair and wore glasses, I lumped them all in as the same person. This wasn't a case of simply not bothering to look and pay attention - this (or one of these) was a person with whom I was talking about my field of interest.
One thing I take from the Boston Globe article is that this is more common than previously thought - to some extent maybe up to 1 in 50 people has this condition.
So, when you consider the "biometric" schemes that offer a pile of faces to choose from, and the user has to select the same person every time, bear in mind that one in 50 people will have trouble with that.