To be an effective expert consultant/expert witness one must have good communications skills, not only interpersonal proficiency for use in dealing with attorneys, but also the ability to testify in deposition and court. The expert must be able to explain complex issues from his/her expertise to a jury of lay people and a judge so that they can understand those issues well enough to make a determination, and also be able to communicate effectively with opposing counsel -- simultaneously! Most people require communications coaching to do their best.