Testing :: in phases

Was reading Matt's blog at Aroxo, and found an interesting little summary of how testing should be conducted before releasing a site live:

Test type	Description	How many people
Over-the-shoulder	The main sticking points in the system. Where the system confuses users. Start when functional testing at 80% readiness. Earlier with mock-ups also possible.	10-15
Task-driven testing	How well the system stands up on its own. Start when the major usability holes uncovered in OTS testing have been fixed.	Start with 20-30 keep growing invites to 100 or so
Goal-driven testing	End-to-end flaws across the system. Start when functional testing at 95% system readiness with a slick UI.	150-200
Beta testing	The marketing points for the site, highlights future developments. If there are enough users it may also reveal performance issues Start when the system is 99% ready.	250+ including members of the public

More information there >>