>>In addition to TESTING, there's determining if the user interface will be Understandable to the average user. We gave each program to an 8-10 yr old (child varied through the years) without directions or manual. If she/he could learn to use it without asking questions, the interface was OK.
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>I think an even better test would be to give the app to one's mom or dad. :)

Good point - I just spent 2 hours this weekend teaching an 82-yr old stepmother to send e-mail and web surf. I hadn't realized how NON-intuitive computer interfaces were!!

However, at the time I was writing OTC software I had parents who were at least as computer-savvy as I was - My father was an electrical engineer who used mainframes the way we use TV remotes.