Blaise Pascal, the scientist philosopher, has good advice immediately applicable during a Q&A when faced with a questioner who disagrees with the presenter.
(Thought 9) When one wishes to correct to one’s advantage, and reveal how mistaken someone is, one must observe from which angle that person is looking at things, because, usually, from that angle, things look right, and openly admit this truth, but present the other angle from which the same things now look wrong. The one who is corrected is satisfied for no mistake was made, it was simply a matter of now being aware of other perspectives; One is not angry for not being able to see all angles, but one does not want to be wrong.
During the Q&A, when people claim that your results cannot be observed in their experiments, you, the presenter, should not argue. If they say so, they do not intend to lie, and therefore, it must be true. The difference can often be explained by differences in experimental conditions, equipment, products, formulas; Naturally, there is no time during a short Q&A to review the differences, you make that clear, and you also make clear that your results are repeatable in your lab (they are, aren’t they…); However, offer your help to understand the differences by meeting with the questioner after the talk with a sentence like “I’d be happy to sit with you after the talk and try and see why you cannot get our results”. You may actually learn something interesting! What is important here is the way the audience perceives you: courteous, firm, confident, helpful. Anything else in your response could make you look arrogant, aggressive, discourteous, or not confident in your own results! Let the forceful questioner look arrogant, aggressive, or discourteous; remain the perfect respectful host.
By Jean-luc Lebrun