Thinking Out Loud: Requirements vs. Criteria

What's the difference?  I can't find any good resources for comparison on the web... I'm thinking:

• Requirements are a list of things that must get done for a project, regardless of their outcome.
• Criteria is the assessment of the results of the activities done to meet those requirements.

You set up requirements so you know what you have to do.  Ex.:

MyApp must run/startup on Vista.

...This lets you know that you (at least) have to write tests that cause MyApp to try to run/start on Vista, then run those tests. You set criteria so you know the level of "quality" to which that requirement was met.  In order to determine the level of quality, you look at the results of running the tests.  Ex.:

Criteria = MyApp must run/startup 100% of the time, in at least 1000 attempts, on each edition of Vista.  MyApp ran/started-up on 5 different Vista Editions, a total 1200 times each, and started 99.999% of the time.

...Criteria not met. Hmm... I think I like it....