Checking for understanding by asking clarifying or testing questions is not effective and does not produce authentic engagement with the class. The sort of questions I am talking about are single answer where the audience are invited to put their hand up to give it a go.
I was recently sitting in an audience where there was a presentation being given. It was a very engaging presenter with great content delivered through slideshows and videos. The presenter was very good at asking clarifying questions to emphasis his point and rewarding the answers for the ones that put their hands up and got it correct with lavish praise.