The scope of user acceptance testing

The scope of user acceptance testing varies greatly. Two key factors that affect scope include the time allocated and the technical expertise of the users executing the testing. Whether or not an application has been tested previously by a testing team before UAT is conducted might be a factor as well.

If time isn't allotted, UAT tends to be reduced. If the users don't advocate for more testing time or understand why they need the time or what other testing could be conducted, UAT can become a short and shallow cycle. If a testing team has tested the product, then the UAT cycle might be more of a signoff exercise.

Most of my experience with UAT has been more of a "feel good" activity.

Users often execute a handful of happy path scenarios and tend to be stumped about what else to test. In one situation, developers and members of the product team stayed in the room during UAT with the idea that they could answer questions for users. I think having the product team watch the users curbed the user testing.

If you're managing a testing team and have been asked to run or be involved with UAT, I would suggest spending time with the users to understand what they want and hope to gain from the experience. I wouldn't rely on UAT as a replacement to testing dedicated test resources offer.