Answer by Robert Frost:

You are doing the right thing.  A teacher that is unwilling to say “I don’t know” is a bad teacher.

For a teacher to be most effective they must earn the trust of their students.  Trust cannot be earned by dishonesty.

This is a hard lesson for people to learn.  People hate saying “I don’t know.” They want to get around that in any way possible. They say things like “I’m not 100% sure.”  No.  You either know the answer or you don’t.  If you aren’t sure, you risk providing negative training by giving them bad information that you will then have to work hard to get them to unlearn.  In my old group, we used to have a foam ball we called the “BS Ball”.  We would throw that ball at people, during their dry-runs, when they began to BS.

In my environment, getting caught BSing can be devastating to your career. The astronauts are putting their lives and careers in our hands when we train them.  They have to have 100% confidence that we can be trusted.  Many years ago, I was teaching a crew member that was known for his sternness.  He asked me a question, I didn’t know the answer so I immediately said “I don’t know.”  We continued and he asked another question and again I said “I don’t know.”  He stood up.  For a brief moment I felt panic – that he was going to walk out of the room because he thought I was a moron that didn’t know my subject.  To the contrary, he leaned over the table and offered his hand.  He shook my hand and he said “Thank you.  You don’t know how many people are unwilling to say that to me.

It takes a lot of work to build trust, but it can be dissolved in moments.  Don’t risk it.

Is it okay if a teacher says “I don’t know” to their students?