I was sitting with one of the tester and he was testing a product. He did some action on the functional module and there was some error / alert message thrown and he just clicked “OK” button and proceeded with correcting the error. Then I asked him what the error message was? He said this was wrong so he corrected it and now its working fine.
Then I asked him to make that error message come again. He did the same actions and got it. Then I analyzed the error message and guess what? I couldn’t understand little bit of that error message.
I questioned that tester,
Is this error message reported under Usability quality criteria?
He said that, “Come on man, what’s wrong with this error message. Didn’t you see that how I understood error message and corrected it to avoid it”.
I responded as, “My friend, you assume that the customers who are using this product understand this?”
[ At this point of time he started thinking ]
I said to him, “You see that I also did not understand this message” but, you understand this because you have been trained on this product and you know the working of this product. But, this error message is not usable for the end-user. As a tester or a programmer you might understand why error message is popping up but an end-user on customer site might not.
Conclusion: Usability is amazing quality criteria ( I love it ). Try to model yourself in different set of end-users and trying to analyze the error message.
Suggested Reading: Are your lights on?