One of the things I try to impress upon my testers is that when testing it is important not to “prove” that the system works correctly, but to find the weaknesses, faults, bugs. If a tester tests looking for the system to do what it is supposed to do, then that is what they will find – nothing (or very little), whereas if they are testing to find faults they are more likely to find them.
It is too easy to think “that is what the specification says, therefore, that is what I will test against”.
I fell into that trap this week. We have a lot of faults that have come back from Development and we have a short timeframe to re-test them. All of the faults are allocated out to team members to retest. One of my testers needed to complete some other work before starting on the re-tests and so I agreed that work needed finishing first, then I said “And then you can close off those faults”. After a short pause, he said “Don’t you mean that I should find the faults in the fixes?”. It was said in a jokey sort of way, but it was a good point!
Two things hit me. First, of course that is what I should have said and it was embarrassing that I had fallen into the trap. Secondly, I was very pleased that the tester had pulled me up on what I said, it means I am getting the mindset of the testers better.
Isn’t it odd though how even seasoned professionals like me can make that type of mistake?