This question is asked to determine how you deal with difficult situations. That means not only the scenario presented, that the boss is wrong, but also the question itself in the interview.
Don’t be afraid of this question. It’s easy to give a strong response when you’re prepared for it.
A good answer is “It depends on the boss and the situation,” followed by some examples.
Newbie, Angry Boss:
“My former boss was pretty new to the job, and very inexperienced. He didn’t really understand what his people did or what it took to do the job. But if anyone corrected him, or told him he was wrong, he got angry. To avoid arguments and to make things run smoothly, I avoided correcting him. No matter what he told me I agreed, then did it the right way if he was wrong. I delivered the results he wanted, without him ever knowing he was wrong or that I did something a different way than he suggested.”
Newbie, Reasonable Boss:
“My last boss had less experience than most of the people she managed. But she didn’t mind hearing that she was wrong, as long as the right way was explained. If I told her ‘it might work better if we try it this way,’ she’d say ‘ok, try it.’”
The important thing is not to answer this in a way that shows you’re out to get the boss. The interviewer is likely going to be your boss, or one of your bosses. Everyone gets things wrong. A good boss would rather be told about a mistake in a way that doesn’t embarrass anyone.
Help the Boss:
“It was an important project, and the boss was dead wrong about the hardware needed to run a new Internet service. I went into his office armed to the teeth with all the proof, and convinced him about what needed to be changed. He had me accompany him to report the new hardware needs to his boss. We spun it as a better solution, not that the original solution was wrong. It was a win-win for both of us and for the company.”
One job seeker was honest. He was probably a little bit too honest.. “I quit.” That answer didn’t earn points for landing the new job.