“I don’t know” is the most powerful thing a teacher can say. Especially when followed up with “Let’s find out.”
It’s unrealistic for a teacher to be an expert on everything. And while it isn’t hard to ‘fake it’, why bother, students will know and that’ll call into question everything you’ve ever taught them and will definitely affect how much they absorb from you in the future.
This is an educational environment. Showing others how to learn is just as important as providing what to learn. It leads to reduced anxiety to experimentation and a willingness to fail among your students. Two incredibly beneficial characteristic’s to develop.
So if you don’t know something just say so and be in awe of how it leads to greater learning.
There are also times where you might know something or have done it before, but might not be the most skilled at. Just straight up explaining it like that goes a long way towards credibility.
“Ok class, we’re going thru different dovetails today and to be complete I want to show you the double blind. Now I’ll admit, I’ve never used this joint in a project. I’m not very good at it. But it has some unique techniques that you will use elsewhere. Understanding both the joint and how it’s cut will open up new ideas for you in the future. So forgive me if we fumble around a bit…”
The hard ones are when you know something but not the why. Make sure you’re up front about that too as this kind of situation opens up great opportunities for discussion which can lead the whole group to deeper understanding. Personally I know that certain modern steels are greatly improving the cutting edges of modern tools and I can explain that to a class. This holds it’s edge longer, this gets keener. But I can’t explain why.
There are also those things that “it’s always been done that way.” So telling students that up front in the context of “my experience has shown me” gives students permission to disagree. Also a good thing in an educational environment.
“I don’t know.” Who woulda thunk that’d be the an opening to learning.