The expert witness is in the advantageous position of being a friend of the court. The psychiatrist in that role has relevant information that outsiders cannot get from the patient. To make his testimony most effective the witness must be aware of courtroom procedures. He should know how to deal with hypothetical questions, references to textbooks and other authorities, and requests for definitions of mental health terms. He should also know whether or not a jury will be present since there is a different atmosphere and use of different courtroom techniques in a jury trial.