As much as I deeply respect you, Barbara, I think a far better test of a user interface--and one I am rarely brave enought to attempt--is having my 72 year old (slightly cranky) Mother use it. <lol>

>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.