Ad Hoc Testing
As a tester in my previous life, I've found the answer to this is no. You might disagree with this statement but I've always found that you end up getting side tracked and going round in circles. You might think that ad hoc testing is part and parcel of testing agile, but think again.
Ok, let me back track slightly and tell you how to be as effective as possible when ad hoc testing to the point where it's not ad hoc.
For example - let's say you've asked to test some functionality you've never seen before, there's no spec and the only other info is maybe a design. You've got limited time and the software is going live ASAP.
In this situration, before you aimlessly click around, think about what's been delivered. Is it common functionality? Can you use a checklist? If so - great! The next thing to do is to spent the next 15 minutes to create a mini test plan and before you know it you're not ad hoc testing anymore.
Use my guides and checklist to assist you in the process
Ray - testertroubles