Re: [Usability] user levels, etc.

[Calum Benson <calum benson sun com>]

Adam Elman wrote:
> 
> There is a
> lot of usability literature that indicates that you tend to get most of
> the same results for a reasonably well-chosen group of, say, 3-5 people
> as for a much larger group.  This is not, of course, true of psychology
> or political polling.

For anyone who's interested, Jakob Neilsen's explanation of this
phenomenon can be found at http://www.useit.com/alertbox/20000319.html.  

(Some more recent work by Jared Spool suggests that anything up to 20
users can still keep finding new, major usability problems in a
usability test, but this seems to be the exception rather than the
rule.)

Cheeri,
Calum.

-- 
CALUM BENSON, Usability Engineer       Sun Microsystems Ireland
mailto:calum benson ireland sun com    Desktop Engineering Group
http://www.sun.ie                      +353 1 819 9771

Any opinions are personal and not necessarily those of Sun Microsystems