A deposition is the opportunity for lawyers to determine what your opinions are and how you will "perform" in the courtroom. Some of the many tricks that will be attempted are: are you being paid for this testimony, you are no expert on this matter, this other expert has a different opinion, asking you about 5 questions at the same time, cutting you off before you are finished answering, and the legendary "We are about done, I have just one more question". There are several key ideas that will help you be successful giving expert testimony: you are in control because you are giving the answers; you can ask for breaks; you can ask for clarification over and over if the question is too vague; you are not the decision maker, others will make decisions with or without your input; and be prepared at the end for attacking questions, so don't relax until you are out of the building.