Expert Testimony

The Four Main Pillars of an Expert Witness

1) Qualifications

The expert is qualified to opine on the case if and only if his or her professional knowledge and skill set will assist the jury in better understanding the evidence. The expert’s knowledge must be above and beyond the knowledge of the jury. He or she does not necessarily have to be the best in the field, nor have all of the facts regarding the case, as long as his or her expertise is relevant.

2) Reliability

The expert’s testimony is admissible so long as the expert uses unambiguous data and follows the standard of practice in his or her field of expertise.

3) Helpfulness

An expert is not considered helpful if his or her assumptions do not apply to the facts of the case. The expert must provide information that is new and not obvious to the jury, making sure that there is no analytical gap in their reasoning.

4) Foundation

The expert’s opinion must be based on foundational facts agreed upon by other experts in the same field. The facts from which the expert derives their conclusion must be accurate and pertinent to the issue of the case.