“…The expert witness helps the "trier of fact"-the judge or jury-make a just determination by providing in readily understandable terms accurate data and a clear and realistic picture of client needs (Broder, 1987;Deutsch & Parker, 1985). This process of rendering an "opinion" derives from analysis of the case, including a review of relevant facts and case records, drawing the requisite inferences, and making appropriate interpretations (Huckins, 1968;Krieshok, 1987;Weikel, 1986). The fact witness, often a physician or psychotherapist, testifies about what he or she knows, has observed, or believes to be true about actual events involving the diagnosis, treatment or counseling mode, and progress of the client in the case.…”