Basically it's about "How to ask the right questions?"
He goes in detail on some of the tips below which helps you to frame your questions in the right way to solicit the right responses.
I guess it takes time and practice, but here is a quick list of them. It's best to read the details with it on the article.
Here's his summary as well. I think the body language aspects of what he is saying is important, particularly to stop nodding if you don't understand. As sometimes we want to give the impression we understand, but really it doesn't do anyone any favours when you do. I generally like to ask questions to align understanding of words, phrases, and sentences, even it makes me look a little silly. As meanings can be easily lost in translation.