Destruction Testing
In this type of testing, the application is tested until it does something it's not supposed to-often in a totally unstructured fashion. You need to come up with a happy medium of what is appropriate. For example, you had 20 days allocated for this testing, and you could let 1 person do this for 20 days or you could let 40 people do this for half a day each. Ideally, about 5 or 6 people for 3 or 4 days each is the best proportion to get the maximum benefit.