§ Rule 702. Testimony by experts

Rule 702. Testimony by experts

If scientific, technical or other specialized knowledge beyond that possessed by a layperson will assist the trier of fact to understand the evidence or to determine a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training or education may testify thereto in the form of an opinion or otherwise.

Comment: Pa.R.E. 702 differs from F.R.E. 702 in that the words “beyond that possessed by a lay person” have been added to make the rule consistent with Pennsylvania law. See Commonwealth v. Dunkle, 529 Pa. 168, 602 A.2d 830 (1992).

Adoption of Pa.R.E. 702 does not alter Pennsylvania's adoption of the standard in Frye v. United States, 293 F. 1013 (D.C. Cir. 1923), which requires scientific evidence to have “general acceptance” in the relevant scientific community. See Commonwealth v. Dunkle, supra; Commonwealth v. Nazarovitch, 496 Pa. 97, 436 A.2d 170 (1981); Commonwealth v. Topa, 471 Pa. 223, 369 A.2d 1277 (1977). In 1993, the United States Supreme Court held that Frye was superseded in the federal courts by the adoption of F.R.E. 702. Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993). In Grady v. Frito-Lay, Inc., 576 Pa. 546, 839 A.2d 1038 (2003), a majority of the Pennsylvania Supreme Court rejected the Daubert standard and affirmed the applicability of the Frye standard in the Pennsylvania state courts.

Pa.R.E. 702 does not change the Pennsylvania rule for qualifying a witness to testify as an expert. In Miller v. Brass Rail Tavern, Inc., 541 Pa. 474, 480-81, 664 A.2d 525, 528 (1995), the Supreme Court stated:

The test to be applied when qualifying a witness to testify as an expert witness is whether the witness has any reasonable pretension to specialized knowledge on the subject under investigation. If he does, he may testify and the weight to be given to such testimony is for the trier of fact to determine.

Pa.R.E. 702 does not change the requirement that an expert's opinion must be expressed with reasonable certainty. See McMahon v. Young, 442 Pa. 484, 276 A.2d 534 (1971).

Pa.R.E. 702 states that an expert may testify in the form of an “opinion or otherwise.” Much of the literature assumes that experts testify only in the form of an opinion. The language “or otherwise” reflects the fact that experts frequently are called upon to educate the trier of fact about the scientific or technical principles relevant to the case. SeeF.R.E. 702 advisory committee notes.