'Non-Scientific' Experts: What Degree of Judicial Scrutiny Should They Face?
Critical Legal Issues Working Paper No. 89
26 Pages Posted: 8 Dec 1998
Date Written: October 1998
This Working Paper discusses the appropriate distinction between scientific and non-scientific evidence. The author concludes that scientific expert evidence is based on theories and/or data that can be subjected to objective rational criticism, while non-scientific expert evidence is based on an expert's experience and/or training.
Next, the Working Paper discusses the appropriate interpretation of Federal Rule of Evidence 702 in the context of non-scientific expert testimony. Rule 702 requires that such testimony be based on expert "knowledge" and be helpful to the jury. To meet the knowledge requirement, trial courts must ensure that a proffered non-scientific expert is either testifying from within a legitimate, recognized field of expertise, or is otherwise able to prove to the court that his testimony is based on true expertise. With regard to the helpfulness requirement, this paper argues that because non-scientific testimony is, by definition, not objectively refutable, attorneys will have strong incentives to hire venal experts or "outliers," those whose views are outside the mainstream.
Adversarial non-scientific expert testimony is therefore unlikely to be helpful to the jury. The only way to ensure that non-scientific expert testimony represents mainstream expert opinion, and not the idiosyncratic results of expert-shopping by a party, is for courts to appoint their own experts, either in place of or in addition to the parties' experts.
JEL Classification: K4
Suggested Citation: Suggested Citation