New tactic during sprint planning meeting

This Monday we held a sprint planning session and I introduced an element from my days as a computer trainer. As always, I started by giving the objectives of the sprint. This time I printed this down in big letters on a paper.

Then, during the session whenever giving a statement I finished this with the questions: "do you know why?" and the developers could themselves present an answer. By doing so, they become more involved in the objectives and mis understandings were discussed up front.

I used this technique, common to many theories for education, all the time when I worked as a computer trainer. Why I dropped this when educating our developers on the problem domain is my failing to see the pattern.