ARTICLE VII. OPINIONS AND EXPERT TESTIMONY
Rule 701. Opinion Testimony by Lay Witnesses
If a witness is not testifying as an expert, testimony in the form of an opinion is limited to one that is:
(a) rationally based on the witness's perception;
(b) helpful to clearly understanding the witness's testimony or to determining a fact in issue; and
(c) not based on scientific, technical, or other specialized knowledge within the scope of Rule 702.
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Notes of Advisory Committee on Proposed Rules
The rule retains the traditional objective of putting the trier of fact in possession of an accurate reproduction of the event.
Limitation (a) is the familiar requirement of first-hand knowledge or observation.
Limitation (b) is phrased in terms of requiring testimony to be helpful in resolving issues. Witnesses often find difficulty in expressing themselves in language which is not that of an opinion or conclusion. While the courts have made concessions in certain recurring situations, necessity as a standard for permitting opinions and conclusions has proved too elusive and too unadaptable to particular situations for purposes of satisfactory judicial administration. McCormick §11. Moreover, the practical impossibility of determinating by rule what is a "fact," demonstrated by a century of litigation of the question of what is a fact for purposes of pleading under the Field Code, extends into evidence also. 7 Wigmore §1919. The rule assumes that the natural characteristics of the adversary system will generally lead to an acceptable result, since the detailed account carries more conviction than the broad assertion, and a lawyer can be expected to display his witness to the best advantage. If he fails to do so, cross-examination and argument will point up the weakness. See Ladd, Expert Testimony, 5 Vand.L.Rev. 414, 415–417 (1952). If, despite these considerations, attempts are made to introduce meaningless assertions which amount to little more than choosing up sides, exclusion for lack of helpfulness is called for by the rule.
The language of the rule is substantially that of Uniform. Rule 56(1). Similar provisions are California Evidence Code §800; Kansas Code of Civil Procedure §60–456(a); New Jersey Evidence Rule 56(1).
Notes of Advisory Committee on Rules—1987 Amendment
The amendments are technical. No substantive change is intended.
Committee Notes on Rules—2000 Amendment
Rule 701 has been amended to eliminate the risk that the reliability requirements set forth in Rule 702 will be evaded through the simple expedient of proffering an expert in lay witness clothing. Under the amendment, a witness' testimony must be scrutinized under the rules regulating expert opinion to the extent that the witness is providing testimony based on scientific, technical, or other specialized knowledge within the scope of Rule 702. See generally Asplundh Mfg. Div. v. Benton Harbor Eng'g, 57 F.3d 1190 (3d Cir. 1995). By channeling testimony that is actually expert testimony to Rule 702, the amendment also ensures that a party will not evade the expert witness disclosure requirements set forth in Fed.R.Civ.P. 26 and Fed.R.Crim.P. 16 by simply calling an expert witness in the guise of a layperson. See Joseph, Emerging Expert Issues Under the 1993 Disclosure Amendments to the Federal Rules of Civil Procedure, 164 F.R.D. 97, 108 (1996) (noting that "there is no good reason to allow what is essentially surprise expert testimony," and that "the Court should be vigilant to preclude manipulative conduct designed to thwart the expert disclosure and discovery process"). See also United States v. Figueroa-Lopez, 125 F.3d 1241, 1246 (9th Cir. 1997) (law enforcement agents testifying that the defendant's conduct was consistent with that of a drug trafficker could not testify as lay witnesses; to permit such testimony under Rule 701 "subverts the requirements of Federal Rule of Criminal Procedure 16(a)(1)(E)").
The amendment does not distinguish between expert and lay witnesses, but rather between expert and lay testimony. Certainly it is possible for the same witness to provide both lay and expert testimony in a single case. See, e.g., United States v. Figueroa-Lopez, 125 F.3d 1241, 1246 (9th Cir. 1997) (law enforcement agents could testify that the defendant was acting suspiciously, without being qualified as experts; however, the rules on experts were applicable where the agents testified on the basis of extensive experience that the defendant was using code words to refer to drug quantities and prices). The amendment makes clear that any part of a witness' testimony that is based upon scientific, technical, or other specialized knowledge within the scope of Rule 702 is governed by the standards of Rule 702 and the corresponding disclosure requirements of the Civil and Criminal Rules.
The amendment is not intended to affect the "prototypical example[s] of the type of evidence contemplated by the adoption of Rule 701 relat[ing] to the appearance of persons or things, identity, the manner of conduct, competency of a person, degrees of light or darkness, sound, size, weight, distance, and an endless number of items that cannot be described factually in words apart from inferences." Asplundh Mfg. Div. v. Benton Harbor Eng'g, 57 F.3d 1190, 1196 (3d Cir. 1995).
For example, most courts have permitted the owner or officer of a business to testify to the value or projected profits of the business, without the necessity of qualifying the witness as an accountant, appraiser, or similar expert. See, e.g., Lightning Lube, Inc. v. Witco Corp. 4 F.3d 1153 (3d Cir. 1993) (no abuse of discretion in permitting the plaintiff's owner to give lay opinion testimony as to damages, as it was based on his knowledge and participation in the day-to-day affairs of the business). Such opinion testimony is admitted not because of experience, training or specialized knowledge within the realm of an expert, but because of the particularized knowledge that the witness has by virtue of his or her position in the business. The amendment does not purport to change this analysis. Similarly, courts have permitted lay witnesses to testify that a substance appeared to be a narcotic, so long as a foundation of familiarity with the substance is established. See, e.g., United States v. Westbrook, 896 F.2d 330 (8th Cir. 1990) (two lay witnesses who were heavy amphetamine users were properly permitted to testify that a substance was amphetamine; but it was error to permit another witness to make such an identification where she had no experience with amphetamines). Such testimony is not based on specialized knowledge within the scope of Rule 702, but rather is based upon a layperson's personal knowledge. If, however, that witness were to describe how a narcotic was manufactured, or to describe the intricate workings of a narcotic distribution network, then the witness would have to qualify as an expert under Rule 702. United States v. Figueroa-Lopez, supra.
The amendment incorporates the distinctions set forth in State v. Brown, 836 S.W.2d 530, 549 (1992), a case involving former Tennessee Rule of Evidence 701, a rule that precluded lay witness testimony based on "special knowledge." In Brown, the court declared that the distinction between lay and expert witness testimony is that lay testimony "results from a process of reasoning familiar in everyday life," while expert testimony "results from a process of reasoning which can be mastered only by specialists in the field." The court in Brown noted that a lay witness with experience could testify that a substance appeared to be blood, but that a witness would have to qualify as an expert before he could testify that bruising around the eyes is indicative of skull trauma. That is the kind of distinction made by the amendment to this Rule.
GAP Report—Proposed Amendment to Rule 701. The Committee made the following changes to the published draft of the proposed amendment to Evidence Rule 701:
1. The words "within the scope of Rule 702" were added at the end of the proposed amendment, to emphasize that the Rule does not require witnesses to qualify as experts unless their testimony is of the type traditionally considered within the purview of Rule 702. The Committee Note was amended to accord with this textual change.
2. The Committee Note was revised to provide further examples of the kind of testimony that could and could not be proffered under the limitation imposed by the proposed amendment.
Committee Notes on Rules—2011 Amendment
The language of Rule 701 has been amended as part of the general restyling of the Evidence Rules to make them more easily understood and to make style and terminology consistent throughout the rules. These changes are intended to be stylistic only. There is no intent to change any result in any ruling on evidence admissibility.
The Committee deleted all reference to an "inference" on the grounds that the deletion made the Rule flow better and easier to read, and because any "inference" is covered by the broader term "opinion." Courts have not made substantive decisions on the basis of any distinction between an opinion and an inference. No change in current practice is intended.
Rule 702. Testimony by Expert Witnesses
A witness who is qualified as an expert by knowledge, skill, experience, training, or education may testify in the form of an opinion or otherwise if the proponent demonstrates to the court that it is more likely than not that:
(a) the expert's scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue;
(b) the testimony is based on sufficient facts or data;
(c) the testimony is the product of reliable principles and methods; and
(d) the expert's opinion reflects a reliable application of the principles and methods to the facts of the case.
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Notes of Advisory Committee on Proposed Rules
An intelligent evaluation of facts is often difficult or impossible without the application of some scientific, technical, or other specialized knowledge. The most common source of this knowledge is the expert witness, although there are other techniques for supplying it.
Most of the literature assumes that experts testify only in the form of opinions. The assumption is logically unfounded. The rule accordingly recognizes that an expert on the stand may give a dissertation or exposition of scientific or other principles relevant to the case, leaving the trier of fact to apply them to the facts. Since much of the criticism of expert testimony has centered upon the hypothetical question, it seems wise to recognize that opinions are not indispensable and to encourage the use of expert testimony in non-opinion form when counsel believes the trier can itself draw the requisite inference. The use of opinions is not abolished by the rule, however. It will continue to be permissible for the experts to take the further step of suggesting the inference which should be drawn from applying the specialized knowledge to the facts. See Rules 703 to 705.
Whether the situation is a proper one for the use of expert testimony is to be determined on the basis of assisting the trier. "There is no more certain test for determining when experts may be used than the common sense inquiry whether the untrained layman would be qualified to determine intelligently and to the best possible degree the particular issue without enlightenment from those having a specialized understanding of the subject involved in the dispute." Ladd, Expert Testimony, 5 Vand.L.Rev. 414, 418 (1952). When opinions are excluded, it is because they are unhelpful and therefore superfluous and a waste of time. 7 Wigmore §1918.
The rule is broadly phrased. The fields of knowledge which may be drawn upon are not limited merely to the "scientific" and "technical" but extend to all "specialized" knowledge. Similarly, the expert is viewed, not in a narrow sense, but as a person qualified by "knowledge, skill, experience, training or education." Thus within the scope of the rule are not only experts in the strictest sense of the word, e.g., physicians, physicists, and architects, but also the large group sometimes called "skilled" witnesses, such as bankers or landowners testifying to land values.
Committee Notes on Rules—2000 Amendment
Rule 702 has been amended in response to Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993), and to the many cases applying Daubert, including Kumho Tire Co. v. Carmichael, 119 S.Ct. 1167 (1999). In Daubert the Court charged trial judges with the responsibility of acting as gatekeepers to exclude unreliable expert testimony, and the Court in Kumho clarified that this gatekeeper function applies to all expert testimony, not just testimony based in science. See also Kumho, 119 S.Ct. at 1178 (citing the Committee Note to the proposed amendment to Rule 702, which had been released for public comment before the date of the Kumho decision). The amendment affirms the trial court's role as gatekeeper and provides some general standards that the trial court must use to assess the reliability and helpfulness of proffered expert testimony. Consistently with Kumho, the Rule as amended provides that all types of expert testimony present questions of admissibility for the trial court in deciding whether the evidence is reliable and helpful. Consequently, the admissibility of all expert testimony is governed by the principles of Rule 104(a). Under that Rule, the proponent has the burden of establishing that the pertinent admissibility requirements are met by a preponderance of the evidence. See Bourjaily v. United States, 483 U.S. 171 (1987).
Daubert set forth a non-exclusive checklist for trial courts to use in assessing the reliability of scientific expert testimony. The specific factors explicated by the Daubert Court are (1) whether the expert's technique or theory can be or has been tested—that is, whether the expert's theory can be challenged in some objective sense, or whether it is instead simply a subjective, conclusory approach that cannot reasonably be assessed for reliability; (2) whether the technique or theory has been subject to peer review and publication; (3) the known or potential rate of error of the technique or theory when applied; (4) the existence and maintenance of standards and controls; and (5) whether the technique or theory has been generally accepted in the scientific community. The Court in Kumho held that these factors might also be applicable in assessing the reliability of nonscientific expert testimony, depending upon "the particular circumstances of the particular case at issue." 119 S.Ct. at 1175.
No attempt has been made to "codify" these specific factors. Daubert itself emphasized that the factors were neither exclusive nor dispositive. Other cases have recognized that not all of the specific Daubert factors can apply to every type of expert testimony. In addition to Kumho, 119 S.Ct. at 1175, see Tyus v. Urban Search Management, 102 F.3d 256 (7th Cir. 1996) (noting that the factors mentioned by the Court in Daubert do not neatly apply to expert testimony from a sociologist). See also Kannankeril v. Terminix Int'l, Inc., 128 F.3d 802, 809 (3d Cir. 1997) (holding that lack of peer review or publication was not dispositive where the expert's opinion was supported by "widely accepted scientific knowledge"). The standards set forth in the amendment are broad enough to require consideration of any or all of the specific Daubert factors where appropriate.
Courts both before and after Daubert have found other factors relevant in determining whether expert testimony is sufficiently reliable to be considered by the trier of fact. These factors include:
(1) Whether experts are "proposing to testify about matters growing naturally and directly out of research they have conducted independent of the litigation, or whether they have developed their opinions expressly for purposes of testifying." Daubert v. Merrell Dow Pharmaceuticals, Inc., 43 F.3d 1311, 1317 (9th Cir. 1995).
(2) Whether the expert has unjustifiably extrapolated from an accepted premise to an unfounded conclusion. See General Elec. Co. v. Joiner, 522 U.S. 136, 146 (1997) (noting that in some cases a trial court "may conclude that there is simply too great an analytical gap between the data and the opinion proffered").
(3) Whether the expert has adequately accounted for obvious alternative explanations. See Claar v. Burlington N.R.R., 29 F.3d 499 (9th Cir. 1994) (testimony excluded where the expert failed to consider other obvious causes for the plaintiff's condition). Compare Ambrosini v. Labarraque, 101 F.3d 129 (D.C.Cir. 1996) (the possibility of some uneliminated causes presents a question of weight, so long as the most obvious causes have been considered and reasonably ruled out by the expert).
(4) Whether the expert "is being as careful as he would be in his regular professional work outside his paid litigation consulting." Sheehan v. Daily Racing Form, Inc., 104 F.3d 940, 942 (7th Cir. 1997). See Kumho Tire Co. v. Carmichael, 119 S.Ct. 1167, 1176 (1999) (Daubert requires the trial court to assure itself that the expert "employs in the courtroom the same level of intellectual rigor that characterizes the practice of an expert in the relevant field").
(5) Whether the field of expertise claimed by the expert is known to reach reliable results for the type of opinion the expert would give. See Kumho Tire Co. v. Carmichael, 119 S.Ct. 1167, 1175 (1999) (Daubert's general acceptance factor does not "help show that an expert's testimony is reliable where the discipline itself lacks reliability, as, for example, do theories grounded in any so-called generally accepted principles of astrology or necromancy."); Moore v. Ashland Chemical, Inc., 151 F.3d 269 (5th Cir. 1998) (en banc) (clinical doctor was properly precluded from testifying to the toxicological cause of the plaintiff's respiratory problem, where the opinion was not sufficiently grounded in scientific methodology); Sterling v. Velsicol Chem. Corp., 855 F.2d 1188 (6th Cir. 1988) (rejecting testimony based on "clinical ecology" as unfounded and unreliable).
All of these factors remain relevant to the determination of the reliability of expert testimony under the Rule as amended. Other factors may also be relevant. See Kumho, 119 S.Ct. 1167, 1176 ("[W]e conclude that the trial judge must have considerable leeway in deciding in a particular case how to go about determining whether particular expert testimony is reliable."). Yet no single factor is necessarily dispositive of the reliability of a particular expert's testimony. See, e.g., Heller v. Shaw Industries, Inc., 167 F.3d 146, 155 (3d Cir. 1999) ("not only must each stage of the expert's testimony be reliable, but each stage must be evaluated practically and flexibly without bright-line exclusionary (or inclusionary) rules."); Daubert v. Merrell Dow Pharmaceuticals, Inc., 43 F.3d 1311, 1317, n.5 (9th Cir. 1995) (noting that some expert disciplines "have the courtroom as a principal theatre of operations" and as to these disciplines "the fact that the expert has developed an expertise principally for purposes of litigation will obviously not be a substantial consideration.").
A review of the caselaw after Daubert shows that the rejection of expert testimony is the exception rather than the rule. Daubert did not work a "seachange over federal evidence law," and "the trial court's role as gatekeeper is not intended to serve as a replacement for the adversary system." United States v. 14.38 Acres of Land Situated in Leflore County, Mississippi, 80 F.3d 1074, 1078 (5th Cir. 1996). As the Court in Daubert stated: "Vigorous cross-examination, presentation of contrary evidence, and careful instruction on the burden of proof are the traditional and appropriate means of attacking shaky but admissible evidence." 509 U.S. at 595. Likewise, this amendment is not intended to provide an excuse for an automatic challenge to the testimony of every expert. See Kumho Tire Co. v. Carmichael, 119 S.Ct. 1167, 1176 (1999) (noting that the trial judge has the discretion "both to avoid unnecessary 'reliability' proceedings in ordinary cases where the reliability of an expert's methods is properly taken for granted, and to require appropriate proceedings in the less usual or more complex cases where cause for questioning the expert's reliability arises.").
When a trial court, applying this amendment, rules that an expert's testimony is reliable, this does not necessarily mean that contradictory expert testimony is unreliable. The amendment is broad enough to permit testimony that is the product of competing principles or methods in the same field of expertise. See, e.g., Heller v. Shaw Industries, Inc., 167 F.3d 146, 160 (3d Cir. 1999) (expert testimony cannot be excluded simply because the expert uses one test rather than another, when both tests are accepted in the field and both reach reliable results). As the court stated in In re Paoli R.R. Yard PCB Litigation, 35 F.3d 717, 744 (3d Cir. 1994), proponents "do not have to demonstrate to the judge by a preponderance of the evidence that the assessments of their experts are correct, they only have to demonstrate by a preponderance of evidence that their opinions are reliable. . . . The evidentiary requirement of reliability is lower than the merits standard of correctness." See also Daubert v. Merrell Dow Pharmaceuticals, Inc., 43 F.3d 1311, 1318 (9th Cir. 1995) (scientific experts might be permitted to testify if they could show that the methods they used were also employed by "a recognized minority of scientists in their field."); Ruiz-Troche v. Pepsi Cola, 161 F.3d 77, 85 (1st Cir. 1998) ("Daubert neither requires nor empowers trial courts to determine which of several competing scientific theories has the best provenance.").
The Court in Daubert declared that the "focus, of course, must be solely on principles and methodology, not on the conclusions they generate." 509 U.S. at 595. Yet as the Court later recognized, "conclusions and methodology are not entirely distinct from one another." General Elec. Co. v. Joiner, 522 U.S. 136, 146 (1997). Under the amendment, as under Daubert, when an expert purports to apply principles and methods in accordance with professional standards, and yet reaches a conclusion that other experts in the field would not reach, the trial court may fairly suspect that the principles and methods have not been faithfully applied. See Lust v. Merrell Dow Pharmaceuticals, Inc., 89 F.3d 594, 598 (9th Cir. 1996). The amendment specifically provides that the trial court must scrutinize not only the principles and methods used by the expert, but also whether those principles and methods have been properly applied to the facts of the case. As the court noted in In re Paoli R.R. Yard PCB Litig., 35 F.3d 717, 745 (3d Cir. 1994), "any step that renders the analysis unreliable . . . renders the expert's testimony inadmissible. This is true whether the step completely changes a reliable methodology or merely misapplies that methodology."
If the expert purports to apply principles and methods to the facts of the case, it is important that this application be conducted reliably. Yet it might also be important in some cases for an expert to educate the factfinder about general principles, without ever attempting to apply these principles to the specific facts of the case. For example, experts might instruct the factfinder on the principles of thermodynamics, or bloodclotting, or on how financial markets respond to corporate reports, without ever knowing about or trying to tie their testimony into the facts of the case. The amendment does not alter the venerable practice of using expert testimony to educate the factfinder on general principles. For this kind of generalized testimony, Rule 702 simply requires that: (1) the expert be qualified; (2) the testimony address a subject matter on which the factfinder can be assisted by an expert; (3) the testimony be reliable; and (4) the testimony "fit" the facts of the case.
As stated earlier, the amendment does not distinguish between scientific and other forms of expert testimony. The trial court's gatekeeping function applies to testimony by any expert. See Kumho Tire Co. v. Carmichael, 119 S.Ct. 1167, 1171 (1999) ("We conclude that Daubert's general holding—setting forth the trial judge's general 'gatekeeping' obligation—applies not only to testimony based on 'scientific' knowledge, but also to testimony based on 'technical' and 'other specialized' knowledge."). While the relevant factors for determining reliability will vary from expertise to expertise, the amendment rejects the premise that an expert's testimony should be treated more permissively simply because it is outside the realm of science. An opinion from an expert who is not a scientist should receive the same degree of scrutiny for reliability as an opinion from an expert who purports to be a scientist. See Watkins v. Telsmith, Inc., 121 F.3d 984, 991 (5th Cir. 1997) ("[I]t seems exactly backwards that experts who purport to rely on general engineering principles and practical experience might escape screening by the district court simply by stating that their conclusions were not reached by any particular method or technique."). Some types of expert testimony will be more objectively verifiable, and subject to the expectations of falsifiability, peer review, and publication, than others. Some types of expert testimony will not rely on anything like a scientific method, and so will have to be evaluated by reference to other standard principles attendant to the particular area of expertise. The trial judge in all cases of proffered expert testimony must find that it is properly grounded, well-reasoned, and not speculative before it can be admitted. The expert's testimony must be grounded in an accepted body of learning or experience in the expert's field, and the expert must explain how the conclusion is so grounded. See, e.g., American College of Trial Lawyers, Standards and Procedures for Determining the Admissibility of Expert Testimony after Daubert, 157 F.R.D. 571, 579 (1994) ("[W]hether the testimony concerns economic principles, accounting standards, property valuation or other non-scientific subjects, it should be evaluated by reference to the 'knowledge and experience' of that particular field.").
The amendment requires that the testimony must be the product of reliable principles and methods that are reliably applied to the facts of the case. While the terms "principles" and "methods" may convey a certain impression when applied to scientific knowledge, they remain relevant when applied to testimony based on technical or other specialized knowledge. For example, when a law enforcement agent testifies regarding the use of code words in a drug transaction, the principle used by the agent is that participants in such transactions regularly use code words to conceal the nature of their activities. The method used by the agent is the application of extensive experience to analyze the meaning of the conversations. So long as the principles and methods are reliable and applied reliably to the facts of the case, this type of testimony should be admitted.
Nothing in this amendment is intended to suggest that experience alone—or experience in conjunction with other knowledge, skill, training or education—may not provide a sufficient foundation for expert testimony. To the contrary, the text of Rule 702 expressly contemplates that an expert may be qualified on the basis of experience. In certain fields, experience is the predominant, if not sole, basis for a great deal of reliable expert testimony. See, e.g., United States v. Jones, 107 F.3d 1147 (6th Cir. 1997) (no abuse of discretion in admitting the testimony of a handwriting examiner who had years of practical experience and extensive training, and who explained his methodology in detail); Tassin v. Sears Roebuck, 946 F.Supp. 1241, 1248 (M.D.La. 1996) (design engineer's testimony can be admissible when the expert's opinions "are based on facts, a reasonable investigation, and traditional technical/mechanical expertise, and he provides a reasonable link between the information and procedures he uses and the conclusions he reaches"). See also Kumho Tire Co. v. Carmichael, 119 S.Ct. 1167, 1178 (1999) (stating that "no one denies that an expert might draw a conclusion from a set of observations based on extensive and specialized experience.").
If the witness is relying solely or primarily on experience, then the witness must explain how that experience leads to the conclusion reached, why that experience is a sufficient basis for the opinion, and how that experience is reliably applied to the facts. The trial court's gatekeeping function requires more than simply "taking the expert's word for it." See Daubert v. Merrell Dow Pharmaceuticals, Inc., 43 F.3d 1311, 1319 (9th Cir. 1995) ("We've been presented with only the experts' qualifications, their conclusions and their assurances of reliability. Under Daubert, that's not enough."). The more subjective and controversial the expert's inquiry, the more likely the testimony should be excluded as unreliable. See O'Conner v. Commonwealth Edison Co., 13 F.3d 1090 (7th Cir. 1994) (expert testimony based on a completely subjective methodology held properly excluded). See also Kumho Tire Co. v. Carmichael, 119 S.Ct. 1167, 1176 (1999) ("[I]t will at times be useful to ask even of a witness whose expertise is based purely on experience, say, a perfume tester able to distinguish among 140 odors at a sniff, whether his preparation is of a kind that others in the field would recognize as acceptable.").
Subpart (1) of Rule 702 calls for a quantitative rather than qualitative analysis. The amendment requires that expert testimony be based on sufficient underlying "facts or data." The term "data" is intended to encompass the reliable opinions of other experts. See the original Advisory Committee Note to Rule 703. The language "facts or data" is broad enough to allow an expert to rely on hypothetical facts that are supported by the evidence. Id.
When facts are in dispute, experts sometimes reach different conclusions based on competing versions of the facts. The emphasis in the amendment on "sufficient facts or data" is not intended to authorize a trial court to exclude an expert's testimony on the ground that the court believes one version of the facts and not the other.
There has been some confusion over the relationship between Rules 702 and 703. The amendment makes clear that the sufficiency of the basis of an expert's testimony is to be decided under Rule 702. Rule 702 sets forth the overarching requirement of reliability, and an analysis of the sufficiency of the expert's basis cannot be divorced from the ultimate reliability of the expert's opinion. In contrast, the "reasonable reliance" requirement of Rule 703 is a relatively narrow inquiry. When an expert relies on inadmissible information, Rule 703 requires the trial court to determine whether that information is of a type reasonably relied on by other experts in the field. If so, the expert can rely on the information in reaching an opinion. However, the question whether the expert is relying on a sufficient basis of information—whether admissible information or not—is governed by the requirements of Rule 702.
The amendment makes no attempt to set forth procedural requirements for exercising the trial court's gatekeeping function over expert testimony. See Daniel J. Capra, The Daubert Puzzle, 38 [32] Ga.L.Rev. 699, 766 (1998) ("Trial courts should be allowed substantial discretion in dealing with Daubert questions; any attempt to codify procedures will likely give rise to unnecessary changes in practice and create difficult questions for appellate review."). Courts have shown considerable ingenuity and flexibility in considering challenges to expert testimony under Daubert, and it is contemplated that this will continue under the amended Rule. See, e.g., Cortes-Irizarry v. Corporacion Insular, 111 F.3d 184 (1st Cir. 1997) (discussing the application of Daubert in ruling on a motion for summary judgment); In re Paoli R.R. Yard PCB Litig., 35 F.3d 717, 736, 739 (3d Cir. 1994) (discussing the use of in limine hearings); Claar v. Burlington N.R.R., 29 F.3d 499, 502–05 (9th Cir. 1994) (discussing the trial court's technique of ordering experts to submit serial affidavits explaining the reasoning and methods underlying their conclusions).
The amendment continues the practice of the original Rule in referring to a qualified witness as an "expert." This was done to provide continuity and to minimize change. The use of the term "expert" in the Rule does not, however, mean that a jury should actually be informed that a qualified witness is testifying as an "expert." Indeed, there is much to be said for a practice that prohibits the use of the term "expert" by both the parties and the court at trial. Such a practice "ensures that trial courts do not inadvertently put their stamp of authority" on a witness's opinion, and protects against the jury's being "overwhelmed by the so-called 'experts'." Hon. Charles Richey, Proposals to Eliminate the Prejudicial Effect of the Use of the Word "Expert" Under the Federal Rules of Evidence in Criminal and Civil Jury Trials, 154 F.R.D. 537, 559 (1994) (setting forth limiting instructions and a standing order employed to prohibit the use of the term "expert" in jury trials).
GAP Report—Proposed Amendment to Rule 702. The Committee made the following changes to the published draft of the proposed amendment to Evidence Rule 702:
1. The word "reliable" was deleted from Subpart (1) of the proposed amendment, in order to avoid an overlap with Evidence Rule 703, and to clarify that an expert opinion need not be excluded simply because it is based on hypothetical facts. The Committee Note was amended to accord with this textual change.
2. The Committee Note was amended throughout to include pertinent references to the Supreme Court's decision in Kumho Tire Co. v. Carmichael, which was rendered after the proposed amendment was released for public comment. Other citations were updated as well.
3. The Committee Note was revised to emphasize that the amendment is not intended to limit the right to jury trial, nor to permit a challenge to the testimony of every expert, nor to preclude the testimony of experience-based experts, nor to prohibit testimony based on competing methodologies within a field of expertise.
4. Language was added to the Committee Note to clarify that no single factor is necessarily dispositive of the reliability inquiry mandated by Evidence Rule 702.
Committee Notes on Rules—2011 Amendment
The language of Rule 702 has been amended as part of the restyling of the Evidence Rules to make them more easily understood and to make style and terminology consistent throughout the rules. These changes are intended to be stylistic only. There is no intent to change any result in any ruling on evidence admissibility.
Committee Notes on Rules—2023 Amendment
Rule 702 has been amended in two respects:
(1) First, the rule has been amended to clarify and emphasize that expert testimony may not be admitted unless the proponent demonstrates to the court that it is more likely than not that the proffered testimony meets the admissibility requirements set forth in the rule. See Rule 104(a). This is the preponderance of the evidence standard that applies to most of the admissibility requirements set forth in the evidence rules. See Bourjaily v. United States, 483 U.S. 171, 175 (1987) ("The preponderance standard ensures that before admitting evidence, the court will have found it more likely than not that the technical issues and policy concerns addressed by the Federal Rules of Evidence have been afforded due consideration."); Huddleston v. United States, 485 U.S. 681, 687 n.5 (1988) ("preliminary factual findings under Rule 104(a) are subject to the preponderance-of-the-evidence standard"). But many courts have held that the critical questions of the sufficiency of an expert's basis, and the application of the expert's methodology, are questions of weight and not admissibility. These rulings are an incorrect application of Rules 702 and 104(a).
There is no intent to raise any negative inference regarding the applicability of the Rule 104(a) standard of proof for other rules. The Committee concluded that emphasizing the preponderance standard in Rule 702 specifically was made necessary by the courts that have failed to apply correctly the reliability requirements of that rule. Nor does the amendment require that the court make a finding of reliability in the absence of objection.
The amendment clarifies that the preponderance standard applies to the three reliability-based requirements added in 2000—requirements that many courts have incorrectly determined to be governed by the more permissive Rule 104(b) standard. But it remains the case that other admissibility requirements in the rule (such as that the expert must be qualified and the expert's testimony must help the trier of fact) are governed by the Rule 104(a) standard as well.
Some challenges to expert testimony will raise matters of weight rather than admissibility even under the Rule 104(a) standard. For example, if the court finds it more likely than not that an expert has a sufficient basis to support an opinion, the fact that the expert has not read every single study that exists will raise a question of weight and not admissibility. But this does not mean, as certain courts have held, that arguments about the sufficiency of an expert's basis always go to weight and not admissibility. Rather it means that once the court has found it more likely than not that the admissibility requirement has been met, any attack by the opponent will go only to the weight of the evidence.
It will often occur that experts come to different conclusions based on contested sets of facts. Where that is so, the Rule 104(a) standard does not necessarily require exclusion of either side's experts. Rather, by deciding the disputed facts, the jury can decide which side's experts to credit. "[P]roponents 'do not have to demonstrate to the judge by a preponderance of the evidence that the assessments of their experts are correct, they only have to demonstrate by a preponderance of evidence that their opinions are reliable. . . . The evidentiary requirement of reliability is lower than the merits standard of correctness.' " Advisory Committee Note to the 2000 amendment to Rule 702, quoting In re Paoli R.R. Yard PCB Litigation, 35 F.3d 717, 744 (3d Cir. 1994).
Rule 702 requires that the expert's knowledge "help" the trier of fact to understand the evidence or to determine a fact in issue. Unfortunately, some courts have required the expert's testimony to "appreciably help" the trier of fact. Applying a higher standard than helpfulness to otherwise reliable expert testimony is unnecessarily strict.
(2) Rule 702(d) has also been amended to emphasize that each expert opinion must stay within the bounds of what can be concluded from a reliable application of the expert's basis and methodology. Judicial gatekeeping is essential because just as jurors may be unable, due to lack of specialized knowledge, to evaluate meaningfully the reliability of scientific and other methods underlying expert opinion, jurors may also lack the specialized knowledge to determine whether the conclusions of an expert go beyond what the expert's basis and methodology may reliably support.
The amendment is especially pertinent to the testimony of forensic experts in both criminal and civil cases. Forensic experts should avoid assertions of absolute or one hundred percent certainty—or to a reasonable degree of scientific certainty—if the methodology is subjective and thus potentially subject to error. In deciding whether to admit forensic expert testimony, the judge should (where possible) receive an estimate of the known or potential rate of error of the methodology employed, based (where appropriate) on studies that reflect how often the method produces accurate results. Expert opinion testimony regarding the weight of feature comparison evidence (i.e., evidence that a set of features corresponds between two examined items) must be limited to those inferences that can reasonably be drawn from a reliable application of the principles and methods. This amendment does not, however, bar testimony that comports with substantive law requiring opinions to a particular degree of certainty.
Nothing in the amendment imposes any new, specific procedures. Rather, the amendment is simply intended to clarify that Rule 104(a)'s requirement applies to expert opinions under Rule 702. Similarly, nothing in the amendment requires the court to nitpick an expert's opinion in order to reach a perfect expression of what the basis and methodology can support. The Rule 104(a) standard does not require perfection. On the other hand, it does not permit the expert to make claims that are unsupported by the expert's basis and methodology.
Rule 703. Bases of an Expert's Opinion Testimony
An expert may base an opinion on facts or data in the case that the expert has been made aware of or personally observed. If experts in the particular field would reasonably rely on those kinds of facts or data in forming an opinion on the subject, they need not be admissible for the opinion to be admitted. But if the facts or data would otherwise be inadmissible, the proponent of the opinion may disclose them to the jury only if their probative value in helping the jury evaluate the opinion substantially outweighs their prejudicial effect.
(
Notes of Advisory Committee on Proposed 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).
Notes of Advisory Committee on Rules—1987 Amendment
The amendment is technical. No substantive change is intended.
Committee Notes on Rules—2000 Amendment
Rule 703 has been amended to emphasize that when an expert reasonably relies on inadmissible information to form an opinion or inference, the underlying information is not admissible simply because the opinion or inference is admitted. Courts have reached different results on how to treat inadmissible information when it is reasonably relied upon by an expert in forming an opinion or drawing an 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 hearsay 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., Ronald 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); Paul 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 admissible only for the purpose of assisting the jury in evaluating an expert's opinion, a trial court applying this Rule must consider the information's probative value in assisting the jury to weigh the expert's opinion on the one hand, and the risk of prejudice resulting from the jury's potential misuse of the information for substantive purposes on the other. The information may be disclosed to the jury, upon objection, only if the trial court finds that the probative value of the information in assisting the jury to evaluate the expert's opinion substantially outweighs its prejudicial effect. If the otherwise inadmissible information is admitted under this balancing test, the trial judge must give a limiting instruction upon request, informing the jury that the underlying information must not be used for substantive purposes. See Rule 105. In determining the appropriate course, the trial court should consider the probable effectiveness or lack of effectiveness of a limiting instruction under the particular circumstances.
The amendment governs only the disclosure to the jury of information that is reasonably relied on by an expert, when that information is not admissible for substantive purposes. It is not intended to affect the admissibility of an expert's testimony. Nor does the amendment prevent an expert from relying on information that is inadmissible for substantive purposes.
Nothing in this Rule restricts the presentation of underlying expert facts or data when offered by an adverse party. See Rule 705. Of course, an adversary's attack on an expert's basis will often open the door to a proponent's rebuttal with information that was reasonably relied upon by the expert, even if that information would not have been discloseable initially under the balancing test provided by this amendment. Moreover, in some circumstances the proponent might wish to disclose information that is relied upon by the expert in order to "remove the sting" from the opponent's anticipated attack, and thereby prevent the jury from drawing an unfair negative inference. The trial court should take this consideration into account in applying the balancing test provided by this amendment.
This amendment covers facts or data that cannot be admitted for any purpose other than to assist the jury to evaluate the expert's opinion. The balancing test provided in this amendment is not applicable to facts or data that are admissible for any other purpose but have not yet been offered for such a purpose at the time the expert testifies.
The amendment provides a presumption against disclosure to the jury of information used as the basis of an expert's opinion and not admissible for any substantive purpose, when 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 amendment.
GAP Report—Proposed Amendment to Rule 703. The Committee made the following changes to the published draft of the proposed amendment to Evidence Rule 703:
1. A minor stylistic change was made in the text, in accordance with the suggestion of the Style Subcommittee of the Standing Committee on Rules of Practice and Procedure.
2. The words "in assisting the jury to evaluate the expert's opinion" were added to the text, to specify the proper purpose for offering the otherwise inadmissible information relied on by an expert. The Committee Note was revised to accord with this change in the text.
3. Stylistic changes were made to the Committee Note.
4. The Committee Note was revised to emphasize that the balancing test set forth in the proposal should be used to determine whether an expert's basis may be disclosed to the jury either (1) in rebuttal or (2) on direct examination to "remove the sting" of an opponent's anticipated attack on an expert's basis.
Committee Notes on Rules—2011 Amendment
The language of Rule 703 has been amended as part of the general restyling of the Evidence Rules to make them more easily understood and to make style and terminology consistent throughout the rules. These changes are intended to be stylistic only. There is no intent to change any result in any ruling on evidence admissibility.
The Committee deleted all reference to an "inference" on the grounds that the deletion made the Rule flow better and easier to read, and because any "inference" is covered by the broader term "opinion." Courts have not made substantive decisions on the basis of any distinction between an opinion and an inference. No change in current practice is intended.
Rule 704. Opinion on an Ultimate Issue
(a)
(b)
(
Notes of Advisory Committee on Proposed Rules
The basic approach to opinions, lay and expert, in these rules is to admit them when helpful to the trier of fact. In order to render this approach fully effective and to allay any doubt on the subject, the so-called "ultimate issue" rule is specifically abolished by the instant rule.
The older cases often contained strictures against allowing witnesses to express opinions upon ultimate issues, as a particular aspect of the rule against opinions. The rule was unduly restrictive, difficult of application, and generally served only to deprive the trier of fact of useful information. 7 Wigmore §§1920, 1921; McCormick §12. The basis usually assigned for the rule, to prevent the witness from "usurping the province of the jury," is aptly characterized as "empty rhetoric." 7 Wigmore §1920, p. 17. Efforts to meet the felt needs of particular situations led to odd verbal circumlocutions which were said not to violate the rule. Thus a witness could express his estimate of the criminal responsibility of an accused in terms of sanity or insanity, but not in terms of ability to tell right from wrong or other more modern standard. And in cases of medical causation, witnesses were sometimes required to couch their opinions in cautious phrases of "might or could," rather than "did," though the result was to deprive many opinions of the positiveness to which they were entitled, accompanied by the hazard of a ruling of insufficiency to support a verdict. In other instances the rule was simply disregarded, and, as concessions to need, opinions were allowed upon such matters as intoxication, speed, handwriting, and value, although more precise coincidence with an ultimate issue would scarcely be possible.
Many modern decisions illustrate the trend to abandon the rule completely. People v. Wilson, 25 Cal.2d 341, 153 P.2d 720 (1944), whether abortion necessary to save life of patient; Clifford-Jacobs Forging Co. v. Industrial Comm., 19 Ill.2d 236, 166 N.E.2d 582 (1960), medical causation; Dowling v. L. H. Shattuck, Inc., 91 N.H. 234, 17 A.2d 529 (1941), proper method of shoring ditch; Schweiger v. Solbeck, 191 Or. 454, 230 P.2d 195 (1951), cause of landslide. In each instance the opinion was allowed.
The abolition of the ultimate issue rule does not lower the bars so as to admit all opinions. Under Rules 701 and 702, opinions must be helpful to the trier of fact, and Rule 403 provides for exclusion of evidence which wastes time. These provisions afford ample assurances against the admission of opinions which would merely tell the jury what result to reach, somewhat in the manner of the oath-helpers of an earlier day. They also stand ready to exclude opinions phrased in terms of inadequately explored legal criteria. Thus the question, "Did T have capacity to make a will?" would be excluded, while the question, "Did T have sufficient mental capacity to know the nature and extent of his property and the natural objects of his bounty and to formulate a rational scheme of distribution?" would be allowed. McCormick §12.
For similar provisions see Uniform Rule 56(4); California Evidence Code §805; Kansas Code of Civil Procedures §60–456(d); New Jersey Evidence Rule 56(3).
Committee Notes on Rules—2011 Amendment
The language of Rule 704 has been amended as part of the general restyling of the Evidence Rules to make them more easily understood and to make style and terminology consistent throughout the rules. These changes are intended to be stylistic only. There is no intent to change any result in any ruling on evidence admissibility.
The Committee deleted all reference to an "inference" on the grounds that the deletion made the Rule flow better and easier to read, and because any "inference" is covered by the broader term "opinion." Courts have not made substantive decisions on the basis of any distinction between an opinion and an inference. No change in current practice is intended.
Amendment by Public Law
1984—
Rule 705. Disclosing the Facts or Data Underlying an Expert's Opinion
Unless the court orders otherwise, an expert may state an opinion—and give the reasons for it—without first testifying to the underlying facts or data. But the expert may be required to disclose those facts or data on cross-examination.
(
Notes of Advisory Committee on Proposed Rules
The hypothetical question has been the target of a great deal of criticism as encouraging partisan bias, affording an opportunity for summing up in the middle of the case, and as complex and time consuming. Ladd, Expert Testimony, 5 Vand.L.Rev. 414, 426–427 (1952). While the rule allows counsel to make disclosure of the underlying facts or data as a preliminary to the giving of an expert opinion, if he chooses, the instances in which he is required to do so are reduced. This is true whether the expert bases his opinion on data furnished him at secondhand or observed by him at firsthand.
The elimination of the requirement of preliminary disclosure at the trial of underlying facts or data has a long background of support. In 1937 the Commissioners on Uniform State Laws incorporated a provision to this effect in the Model Expert Testimony Act, which furnished the basis for Uniform Rules 57 and 58. Rule 4515, N.Y. CPLR (McKinney 1963), provides:
"Unless the court orders otherwise, questions calling for the opinion of an expert witness need not be hypothetical in form, and the witness may state his opinion and reasons without first specifying the data upon which it is based. Upon cross-examination, he may be required to specify the data * * *,"
See also California Evidence Code §802; Kansas Code of Civil Procedure §§60–456, 60–457; New Jersey Evidence Rules 57, 58.
If the objection is made that leaving it to the cross-examiner to bring out the supporting data is essentially unfair, the answer is that he is under no compulsion to bring out any facts or data except those unfavorable to the opinion. The answer assumes that the cross-examiner has the advance knowledge which is essential for effective cross-examination. This advance knowledge has been afforded, though imperfectly, by the traditional foundation requirement. Rule 26(b)(4) of the Rules of Civil Procedure, as revised, provides for substantial discovery in this area, obviating in large measure the obstacles which have been raised in some instances to discovery of findings, underlying data, and even the identity of the experts. Friedenthal, Discovery and Use of an Adverse Party's Expert Information, 14 Stan.L.Rev. 455 (1962).
These safeguards are reinforced by the discretionary power of the judge to require preliminary disclosure in any event.
Notes of Advisory Committee on Rules—1987 Amendment
The amendment is technical. No substantive change is intended.
Notes of Advisory Committee on Rules—1993 Amendment
This rule, which relates to the manner of presenting testimony at trial, is revised to avoid an arguable conflict with revised Rules 26(a)(2)(B) and 26(e)(1) of the Federal Rules of Civil Procedure or with revised Rule 16 of the Federal Rules of Criminal Procedure, which require disclosure in advance of trial of the basis and reasons for an expert's opinions.
If a serious question is raised under Rule 702 or 703 as to the admissibility of expert testimony, disclosure of the underlying facts or data on which opinions are based may, of course, be needed by the court before deciding whether, and to what extent, the person should be allowed to testify. This rule does not preclude such an inquiry.
Committee Notes on Rules—2011 Amendment
The language of Rule 705 has been amended as part of the general restyling of the Evidence Rules to make them more easily understood and to make style and terminology consistent throughout the rules. These changes are intended to be stylistic only. There is no intent to change any result in any ruling on evidence admissibility.
The Committee deleted all reference to an "inference" on the grounds that the deletion made the Rule flow better and easier to read, and because any "inference" is covered by the broader term "opinion." Courts have not made substantive decisions on the basis of any distinction between an opinion and an inference. No change in current practice is intended.
Rule 706. Court-Appointed Expert Witnesses
(a)
(b)
(1) must advise the parties of any findings the expert makes;
(2) may be deposed by any party;
(3) may be called to testify by the court or any party; and
(4) may be cross-examined by any party, including the party that called the expert.
(c)
(1) in a criminal case or in a civil case involving just compensation under the Fifth Amendment, from any funds that are provided by law; and
(2) in any other civil case, by the parties in the proportion and at the time that the court directs—and the compensation is then charged like other costs.
(d)
(e)
(
Notes of Advisory Committee on Proposed Rules
The practice of shopping for experts, the venality of some experts, and the reluctance of many reputable experts to involve themselves in litigation, have been matters of deep concern. Though the contention is made that court appointed experts acquire an aura of infallibility to which they are not entitled. Levy, Impartial Medical Testimony—Revisited, 34 Temple L.Q. 416 (1961), the trend is increasingly to provide for their use. While experience indicates that actual appointment is a relatively infrequent occurrence, the assumption may be made that the availability of the procedure in itself decreases the need for resorting to it. The ever-present possibility that the judge may appoint an expert in a given case must inevitably exert a sobering effect on the expert witness of a party and upon the person utilizing his services.
The inherent power of a trial judge to appoint an expert of his own choosing is virtually unquestioned. Scott v. Spanjer Bros., Inc., 298 F.2d 928 (2d Cir. 1962); Danville Tobacco Assn. v. Bryant-Buckner Associates, Inc., 333 F.2d 202 (4th Cir. 1964); Sink, The Unused Power of a Federal Judge to Call His Own Expert Witnesses, 29 S.Cal.L.Rev. 195 (1956); 2 Wigmore §563, 9 Id. §2484; Annot., 95 A.L.R.2d 383. Hence the problem becomes largely one of detail.
The New York plan is well known and is described in Report by Special Committee of the Association of the Bar of the City of New York: Impartial Medical Testimony (1956). On recommendation of the Section of Judicial Administration, local adoption of an impartial medical plan was endorsed by the American Bar Association. 82 A.B.A.Rep. 184–185 (1957). Descriptions and analyses of plans in effect in various parts of the country are found in Van Dusen, A United States District Judge's View of the Impartial Medical Expert System, 322 F.R.D. 498 (1963); Wick and Kightlinger, Impartial Medical Testimony Under the Federal Civil Rules: A Tale of Three Doctors, 34 Ins. Counsel J. 115 (1967); and numerous articles collected in Klein, Judicial Administration and the Legal Profession 393 (1963). Statutes and rules include California Evidence Code §§730–733; Illinois Supreme Court Rule 215(d), Ill.Rev.Stat.1969, c. 110A, §215(d); Burns Indiana Stats. 1956, §9–1702; Wisconsin Stats.Annot.1958, §957.27.
In the federal practice, a comprehensive scheme for court appointed experts was initiated with the adoption of Rule 28 of the Federal Rules of Criminal Procedure in 1946. The Judicial Conference of the United States in 1953 considered court appointed experts in civil cases, but only with respect to whether they should be compensated from public funds, a proposal which was rejected. Report of the Judicial Conference of the United States 23 (1953). The present rule expands the practice to include civil cases.
Subdivision (a) is based on Rule 28 of the Federal Rules of Criminal Procedure, with a few changes, mainly in the interest of clarity. Language has been added to provide specifically for the appointment either on motion of a party or on the judge's own motion. A provision subjecting the court appointed expert to deposition procedures has been incorporated. The rule has been revised to make definite the right of any party, including the party calling him, to cross-examine.
Subdivision (b) combines the present provision for compensation in criminal cases with what seems to be a fair and feasible handling of civil cases, originally found in the Model Act and carried from there into Uniform Rule 60. See also California Evidence Code §§730–731. The special provision for Fifth Amendment compensation cases is designed to guard against reducing constitutionally guaranteed just compensation by requiring the recipient to pay costs. See Rule 71A(l) of the Rules of Civil Procedure.
Subdivision (c) seems to be essential if the use of court appointed experts is to be fully effective. Uniform Rule 61 so provides.
Subdivision (d) is in essence the last sentence of Rule 28(a) of the Federal Rules of Criminal Procedure.
Notes of Advisory Committee on Rules—1987 Amendment
The amendments are technical. No substantive change is intended.
Committee Notes on Rules—2011 Amendment
The language of Rule 706 has been amended as part of the restyling of the Evidence Rules to make them more easily understood and to make style and terminology consistent throughout the rules. These changes are intended to be stylistic only. There is no intent to change any result in any ruling on evidence admissibility.