Proposed Advisory Committee Note to 2000 Amendment to Rule 703

Rule 703 has been amended to emphasize that when an expert reasonably relies on inadmissible information to form an opinion or inference, it is the opinion or inference, and not the information, that is admitted as evidence. Courts have reached different results on how to treat inadmissible information that is reasonably relied upon by an expert in forming an opinion or inference. Compare United States v. Rollins, 862 F.2d 1282 (7th Cir. 1988) (admitting, as part of the basis of an FBI agent's expert opinion on the meaning of code language, the statements of an informant), with United States v. 0.59 Acres of Land, 109 F.3d 1493 (9th Cir. 1997) (error to admit hearsay offered as the basis of an expert opinion without a limiting instruction). Commentators have also taken differing views. See, e.g., Carlson, Policing the Bases of Modern Expert Testimony, 39 Vand.L.Rev. 577 (1986) (advocating limits on the jury's consideration of otherwise inadmissible evidence used as the basis for an expert opinion); Rice, Inadmissible Evidence as a Basis for Expert Testimony: A Response to Professor Carlson, 40 Vand.L.Rev. 583 (1987) (advocating unrestricted use of information reasonably relied upon by an expert).

When information is reasonably relied upon by an expert and yet is not independently admissible, a trial judge applying this Rule may treat the underlying bases of expert testimony in several different ways, depending on the balance of probative value on the one hand and the risk of prejudice and confusion on the other. First, the court may permit the expert to disclose the details of the inadmissible information to the jury. If this option is chosen, a limiting instruction must be given upon request, to inform the jury that the underlying information may not be used for substantive purposes. See Rule 105. Second, the court may limit disclosure to a general reference to the source or nature of the inadmissible information. This option presents a compromise between the proponent's interest in educating the jury about the expert's opinion, and the opponent's concern that the evidence will be used improperly as substantive evidence. Finally, the court may preclude any mention of the inadmissible information, allowing only the expert testimony that is predicated upon it. In determining the appropriate course, the court should consider the probable effectiveness or lack of effectiveness of a limiting instruction under the particular circumstances.

The amendment governs the use before the jury of inadmissible information reasonably relied on by an expert. It is not intended to affect the admissibility of an expert's testimony, or to deprive an expert of the use of unadmitted hearsay to form and propound an expert opinion or inference. Nothing in this Rule restricts the presentation of underlying expert facts or data when offered by an adverse party. See Rule 705.

The amendment provides a presumption against disclosure to the jury of otherwise inadmissible information used as the basis of an expert's opinion or inference, where that information is offered by the proponent of the expert. In a multi-party case, where one party proffers an expert whose testimony is also beneficial to other parties, each such party should be deemed a "proponent" within the meaning of the Rule.

Notes of the Advisory Committee on Rules

Facts or data upon which expert opinions are based may, under the rule, be derived from three possible sources. The first is the firsthand observation of the witness, with opinions based thereon traditionally allowed. A treating physician affords an example. Rheingold, The Basis of Medical Testimony, 15 Vand. L. Rev. 473, 489 (1962). Whether he must first relate his observations is treated in Rule 705. The second source, presentation at the trial, also reflects existing practice. The technique may be the familiar hypothetical question or having the expert attend the trial and hear the testimony establishing the facts. Problems of determining what testimony the expert relied upon, when the latter technique is employed and the testimony is in conflict, may be resolved by resort to Rule 705. The third source contemplated by the rule consists of presentation of data to the expert outside of court and other than by his own perception. In this respect the rule is designed to broaden the basis for expert opinions beyond that current in many jurisdictions and to bring the judicial practice into line with the practice of the experts themselves when not in court. Thus a physician in his own practice bases his diagnosis on information from numerous sources and of considerable variety, including statements by patients and relatives, reports and opinions from nurses, technicians and other doctors, hospital records, and X rays. Most of them are admissible in evidence, but only with the expenditure of substantial time in producing and examining various authenticating witnesses. The physician makes life-and-death decisions in reliance upon them. His validation, expertly performed and subject to cross-examination, ought to suffice for judicial purposes. Rheingold, supra, at 531; McCormick § 15. A similar provision is California Evidence Code § 801(b).

The rule also offers a more satisfactory basis for ruling upon the admissibility of public opinion poll evidence. Attention is directed to the validity of the techniques employed rather than to relatively fruitless inquiries whether hearsay is involved. See Judge Feinberg's careful analysis in Zippo Mfg. Co. v. Rogers Imports, Inc., 216 F.Supp. 670 (S.D.N.Y. 1963). See also Blum et al, The Art of Opinion Research: A Lawyer's Appraisal of an Emerging Service, 24 U. Chi. L. Rev. 1 (1956); Bonynge, Trademark Surveys and Techniques and Their Use in Litigation, 48 A.B.A.J. 329 (1962); Zeisel, The Uniqueness of Survey Evidence, 45 Cornell L.Q. 322 (1960); Annot., 76 A.L.R.2d 919.

If it be feared that enlargement of permissible data may tend to break down the rules of exclusion unduly, notice should be taken that the rule requires that the facts or data "be of a type reasonably relied upon by experts in the particular field." The language would not warrant admitting in evidence the opinion of an "accidentologist" as to the point of impact in an automobile collision based on statements of bystanders, since this requirement is not satisfied. See Comment, Cal. Law Rev. Comm'n, Recommendation Proposing an Evidence Code 148-150 (1965).