Order of Operations for System Testing?

I was taking an exam yesterday, and I noticed they asked in which order the following occur (and I'll put the order I deemed it to be here):

1. Unit Testing (Always write your unit tests first!)
2. Integration Testing (After you have some code and it works with other code / systems)
3. Validation Testing (Keep your data in a consistent state and make sure no bad data is input)
4. User / Acceptance Testing (It's all about the users otherwise why are we building a system in the first place?)

Is this about right?

Personally I think load-testing or database tuning oughta be in there at the end, but it wasn't on the test.