Ohio R. Evid. 702
A witness may testify as an expert if all of the following apply:
Ohio. R. Evid. 702
Staff Note (July 1, 1994 Amendment)
Rule 702 Testimony by Experts
The amendment is intended to clarify the circumstances in which expert testimony is admissible, a subject on which the language of the pre-amendment rule has proved to be uninformative and, at times, misleading. Because the intention is to reflect the Ohio Supreme Court's interpretations of the rule's preamendment language, no substantive change from prior law is intended. In particular, there is no intention to change existing Ohio law regarding the reliability of expert testimony.
As originally adopted, Evid. R. 702 employed the same language as is used in the Federal Rules of Evidence to define the admissibility of expert testimony. That language permits a witness with the appropriate expertise to testify as an expert if the testimony "will assist the trier of fact." Evid. R. 702 (1980); F.R. Evid., Rule 702.
The "assist the trier" standard has been the subject of widely varying interpretations in the jurisdictions that have adopted it. In Ohio, however, decisions by the Supreme Court have established that the phrase incorporates two distinct admissibility requirements in addition tot the witness's expertise.
First, as at common law, an expert's testimony "assist[s] the trier" only if it relates to a matter "beyond the ken" of the ordinary person. State v. Koss (1990), 49 Ohio St. 3d 213, 216 (expert testimony is not admissible "when such knowledge is within the ken of the jury"); State v. Buell (1980), 22 Ohio St. 3d 124, 131 (expert testimony is admissible if the subject is "sufficiently beyond common experience), cert denied, 479 U.S. 871 (1986); State v. Thomas (1981), 66 Ohio St. 2d 518, 521 (expert testimony is inadmissible if the subject is not "beyond the ken of the average lay person").
Second, the expert's testimony "Assist[s] the trier" only if it meets a threshold standard of reliability, as established either by testimony or by judicial notice. (The trier of fact remains free, of course to make its own assessment of reliability and to accept or reject the testimony accordingly once it has been admitted.) See State v. Bresson (1990), 51 Ohio St. 3d 123, 128 (prior case-law establishing reliability of test sufficed to show reliability as a general matter, and test was admissible on a case-specific showing regarding the tester's qualifications and the reliability of the specific test administration); State v. Williams (1983), 4 Ohio St. 3d 53, 59 (expert testimony as to test was admissible "[I]n view of the unrebutted evidence of reliability of [the test] in general, and of [the witness's] analysis in particular"). See also State v. Pierce (1992), 64 Ohio St. 3d 490, 494-501 (scientific evidence was admissible where unreliability in specific case was not shown and where balance of probative value and reliability against risk of misleading or confusing the jury did not warrant exclusion).
As to the reliability requirement, the Ohio cases have not adopted a definitive test of the showing required for expert testimony generally. The Ohio cases have, however, clearly rejected the standard of Frye v. United States (D.C. Cir. 1923), 293 F. 1013, under which scientific opinions are admissible only if the theory or test in question enjoys "general acceptance" within a relevant scientific community. See Williams, supra, 4 Ohio St. 3d at 58; Pierce, supra, 64 Ohio St. 3d at 496. See also Daubert v. Merrell Dow Pharmaceuticals, Inc. (1993, ____ U.S. ____, 113 S. Ct. 2786 (similarly rejecting Frye and describing the reliability standard to be employed under the federal counterpart to Evid. R. 702.)
Under Ohio law it is also clear that reliability is properly determined only by reference to the principles and methods employed by the expert witness, without regard to whether the court regards the witness's conclusions themselves as persuasive or correct. See Pierce, supra, 64 Ohio St. 3d at 498 (emphasizing that unreliability could not be shown by differences in the conclusions of experts, without evidence that the procedures employed were "somehow deficient"). See also Daubert, supra, 113 S.Ct. at 2797 (the focus "must be solely on principles and methodology, not on the conclusions they generate").
In view of the interpretation given to the "assist the trier" standard by the Ohio Supreme Court's decisions, the rule's original language has been at best uninformative, and it appears to have been affirmatively misleading in some cases. It has been unhelpful to courts and attorneys seeking guidance on the admissibility of challenged testimony, often in the midst of trial, because the language itself does not self-evidently convey the specific content that has been given to it by authoritative judicial interpretations.
Moreover, a review of intermediate appellate decisions suggests that the language has been misleading to at least some Ohio lawyers and courts. In particular, in some cases, the parties and the courts have relied on decisions from other jurisdictions that have given a different content to the phrase "assist the trier," and they have as a result mistakenly assumed that Ohio law is in accord with the law of those other jurisdictions.
The amendment is intended to enhance the utility of the rule, and to reduce the occasions for mistaken interpretation, by substituting a codification of the above-noted Supreme Court holdings in place of the vague and misleading "assist the trier" language. Thus, the amended rule expressly states the three existing requirements for the admissibility of expert testimony:
(1) The witness must be qualified to testify by reason of specialized knowledge, skill, experience, training, or education. Evid. R. 702(B), incorporating original Evid. R. 702.
(2) The witness's testimony must relate to matters beyond the knowledge or experience possessed by lay persons, or dispel a misconception common among lay persons. Evid. R. 702(A), codifying Koss, Buell, and Thomas, supra. (The reference to "dispel[ling] a misconception" is a codification of the specific holding in Koss, supra, 49 Ohio St. 3d at 216, that the permissible subject matter of expert testimony includes not only matters beyond common knowledge, but also matters of common but mistaken belief.)
(3) The witness's testimony must have its basis in reliable scientific, technical, or otherwise specialized knowledge. Evid. R. 702(C), codifying Bresson and Williams, supra. As to evidence regarding a "test, procedure, or experiment," reliability must be shown both as to the test generally (that is, the underlying theory and the implementation of the theory), Evid. R. 702(C)(1) and (2), and as to the specific application. Evid. R. 702(C)(3). See Bresson, supra; Williams, supra. See generally 1 P. Giannelli and E. Imwinkelried, Scientific Evidence 1-2 (2d ed. 1993).
Consistent with the intention to do no more than codify existing holdings on the admissibility of expert testimony, the amended rule does not attempt to define the standard of reliability but leaves that to further development through case law. The amendment also leaves unchanged Ohio's rejection of Frye as the exclusive standard of reliability. Similarly, the amendment does not purport to supplant existing case law as to the acceptable means for showing reliability, whether through judicial notice or testimony. Further, the law remains unchanged that the inquiry as to reliability is appropriately directed, not to the correctness or credibility of the conclusions reached by the expert witness, but to the reliability of the principles and methods used to reach those conclusions.
(While decisions under the federal rules of evidence are frequently inapposite to the interpretation of the Ohio rules, see Evid. R. 102, the federal counterpart to Evid. R. 702 has been interpreted as incorporating a reliability requirement. Daubert, supra. To that extent, the United States Supreme Court's discussion of the considerations that may be relevant to a reliability determination may also be helpful in construing the Ohio rule. See id., 113 S. Ct. at 2795-2796.)
Because the amendment is not intended to change existing law, the procedure for challenging and determining the admissibility of expert proofs likewise remains unchanged. As has been true under the original rule, there may be cases where the issues raised by a proffer of expert testimony can be most efficiently resolved by pre-trial hearing, briefing, and argument. In other cases, however, the issues can be resolved as adequately by objection and decision during trial. In either case, these have been, and will continue to be, matters that are determined by the timing of the parties' motions and by the scheduling and supervisory authority of the trial court.