So many people work together to create a perfect scenario to shoot a movie scene but the actor is the one who really gives life to the scene. Wondering what my point is? The point is preparing to do something is a lot easier than actually doing it. Take the example of your dissertation defense presentation, preparing your dissertation is something else and presenting it in front of a curious and furious board is totally different.
But there are a few things which can help you make your dissertation defense presentation a lot better.
Just like other dissertation presentations, in your dissertation defense presentation you really have to believe in yourself and your knowledge to successfully neutralize the pressure and answer the questions efficiently. You have to demonstrate your competence with appropriate answers and confidence display.
Even if you are not 100 % sure about any question don’t loose it and come up with an answer using whatever related knowledge you have. But never insist on something you know isn’t right.
Before your dissertation defense presentation you can also practice in front of a mirror or ask your friends to play a board member and cross question you.