UAT isn't about finding bugs that couldn't have been found in system testing. UAT is about the user (or the person paying for the thing) making a final run of the software to see that they are getting what they thought they were getting.
UAT criteria is going to be defined by the customer.
Edwin is referring to the question in the CSTE exam. I think I can rephrase it better:
Your customer and his team are willing to be involved in user acceptance testing. As a test manager you are required to list out the types of tests that your user's team can perform more effectively than your testing team.
What is expected is atleast 4 different tests and the qualifications for including them - 10 marks.
I identified the following types:
1. Domain -specific tests.
2. Usability tests.
3. Business flow tests.
4. Tests involving interfacing with non-computer based systems etc.
And then I wrote a whole lot of blah about the hows and whys :-)
[This message has been edited by punekar (edited 12-19-2001).]