Rule 702 Testimony by Experts

LibraryThe Illinois Rules of Evidence: A Color-Coded Guide (2019 Ed.)

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:

(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 has reliably applied the principles and methods to the facts of the case.

ILLINOIS RULES OF EVIDENCE

Rule 702. Testimony by Experts

If scientific, technical, or other specialized knowledge 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. Where an expert witness testifies to an opinion based on a new or novel scientific methodology or principle, the proponent of the opinion has the burden of showing the methodology or scientific principle on which the opinion is based is sufficiently established to have gained general acceptance in the particular field in which it belongs.

Committee Comment to Rule 702

Rule 702 confirms that Illinois is a Frye state. The second sentence of the rule enunciates the core principles of the Frye test for admissibility of scientific evidence as set forth in Donaldson v. Central Illinois Public Service Co., 199 Ill. 2d 63, 767 N.E.2d 314 (2002).

COMMENTARY
Author's Commentary on Fed. R. Evid. 702

FRE 702 differs from its Illinois counterpart. The difference is found in FRE 702(b), (c), and (d), which have not been adopted in Illinois. Those three subdivisions—which originally were numbered (1), (2), and (3), the current letters of the alphabet having resulted from amendments solely for stylistic purposes effective December 1, 2011— were added in 2000 in affirmation of the earlier Daubert test, based on the 1993 U.S. Supreme Court decision discussed just below. Before its year 2000 amendment, FRE 702 consisted of a single sentence that was identical to the first sentence of IRE 702. Under the test supplied by Daubert—together with what is now FRE 702(b), (c), and (d)—the trial court acts as a gate-keeper whose role is to determine whether the expert's testimony rests on a reliable foundation and is relevant to the facts at issue.

Illinois has not adopted the Daubert test. It remains a Frye state—providing a test that applies only to new or novel scientific methodologies or principles and is defined in the final sentence of IRE 702. Where the Frye test has been satisfied in Illinois, subdivisions (b), (c), and (d) of the federal rule have application only for the determination by the trier of fact of the weight to be given to the expert's testimony, not for the trial judge's acting as a gate-keeper in determining admissibility in the first instance.

An understanding of the rules relating to expert opinion evidence in the Federal Rules of Evidence begins with three key decisions of the United States Supreme Court, sometimes referred to as the "Daubert trilogy."

Daubert v. Merrell Dow Pharmaceuticals, Inc.

In Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993), the United States Supreme Court held that the general acceptance test of Frye v. United States, 293 F. 1013 (D.C. Cir. 1923) was superseded by the adoption of FRE 702, which at the time was a single sentence identical to the first sentence of current IRE 702. Interpreting the rule as providing a "screening" or "gate-keeping" role for the trial court, the Court held that, "under the Rules the trial judge must ensure that any and all scientific testimony or evidence admitted is not only relevant, but reliable." The trial court must therefore make "a preliminary assessment of whether the reasoning or methodology underlying the testimony is scientifically valid and of whether that reasoning or methodology properly can be applied to the facts in issue."

The considerations that bear on the trial court's inquiry in determining "whether a theory or technique is scientific knowledge that will assist the trier of fact will be [1] whether it can be (and has been) tested" (i.e., whether the methodology has been tested or is testable); (2) "whether the theory or technique [i.e., methodology] has been subjected to peer review and publication;" (3) whether the methodology has a "known or potential rate of error, *** and the existence and maintenance of standards controlling the technique's operation;" and (4) whether the methodology has general acceptance within the relevant scientific community (i.e., the Frye test). The Supreme Court stressed that the inquiry is a flexible one, and that the focus "must be solely on principles and methodology, not on the conclusions they generate."

Note that Daubert does not exclude expert testimony that may be deemed to be "incorrect" merely because it may not be reconcilable with other testimony. This is illustrated by the decision of the Seventh Circuit Court of Appeals in Stuhlmacher v. Home Depot U.S.A., Inc., 774 F.3d 405 (7th Cir. 2014). There, the magistrate judge struck the testimony of an accident reconstruction expert about a defect in the ladder from which the plaintiff fell, a defect that caused instability in the ladder. The judge initially had found the expert's testimony admissible, but struck his testimony based on the conclusion that the expert's testimony could not be reconciled with the testimony of the plaintiff, who had not testified about the instability of the ladder. In sum, although the judge found the expert's testimony reliable, he struck it as irrelevant under Daubert because he found the expert's version and the plaintiff's version to be irreconcilable. Reasoning that the jury could have found that the expert's theory was credible and that the plaintiff's testimony merely reflected his memory of the event as it was happening, the Seventh Circuit reversed the judgment for the defendants and remanded for further proceedings, holding:

"It is not the trial judge's job to determine whether the expert's opinion is correct. Instead, under the relevancy prong, the judge is limited to determining whether expert testimony is pertinent to an issue in the case. Here, the judge improperly expanded his role beyond gatekeeper to trier of fact." Stuhlmacher, 774 F.3d at 409 (internal citations omitted).

In United States v. Tingle, 880 F.3d 350 (7th Cir. 2018), the circuit court criticized the district court's practice of not identifying expert witnesses:

"The Federal Rules of Evidence and Supreme Court precedent make clear that courts must examine the qualifications of expert witnesses and consider whether the expert's testimony will be helpful to the jury. The district court cannot use such procedures [the practice of not identifying expert witnesses] to avoid its gatekeeper responsibility." Tingle, 880 F.3d at 854.

General Electric Co. v. Joiner

In General Electric Co. v. Joiner, 522 U.S. 136 (1997), the Supreme Court held that abuse of discretion, which is the standard ordinarily used to review evidentiary rulings, also is the proper standard for review of a trial court's admission or exclusion of expert scientific evidence. Applying standards provided by Daubert, the Court approved the trial court's exclusion of the experts' opinions in this case because studies cited by the experts about experiments on infant mice were dissimilar to what allegedly occurred to the adult human plaintiff, and the epidemiological studies relied upon by the experts did not constitute a sufficient basis for their conclusions. In rejecting the argument that the trial court had erred by failing to adhere to language in Daubert that the "focus, of course, must be solely on principles and methodology, not on the conclusions that they generate," the Court stated:

"But conclusions and methodology are not entirely distinct from one another. Trained experts commonly extrapolate from existing data. But nothing in either Daubert or the Federal Rules of Evidence requires a district court to admit opinion evidence which is connected to existing data only by the ipse dixit of the expert. A court may conclude that there is simply too great an analytical gap between the data and the opinion proffered." General Electric Co. v. Joiner, 522 U.S. at 146.

In other words, while Daubert stressed the importance of methodology, Joiner holds that the expert's conclusion also must correlate with supportive data. The expert's mere statements (his ipse dixit) alone are insufficient.

Kumho Tire Co. v. Carmichael

In Kumho Tire Co. v. Carmichael, 526 U.S. 137 (1999), the Court held that, although Daubert referred only to scientific testimony because that was the expertise at issue in that case, the trial court's gate-keeping responsibility regarding relevance and reliability applies not only to "scientific" testimony but to all expert testimony—that involving technical and other specialized knowledge as well. Pointing out Daubert's description of the Rule 702 inquiry as a "flexible one" that allows consideration of other specific factors as well as non-application of some of those provided in Daubert, the Court stressed that the factors mentioned in Daubert do not constitute a "definitive checklist or test," and that the gate-keeping inquiry must be tied to the facts of a particular case.

Seventh Circuit Summary of Daubert Principles

In Krik v. Exxon Mobile Corp., 870 F.3d 669 (7th Cir. 2017), a decision citing other circuit opinions and one that negated causation theories that posit that any exposure to asbestos fibers whatsoever, regardless of the amount of fibers or length of exposure constitutes an underlying cause of injury to the exposed individual, the Seventh Circuit provided the following summarization of Daubert principles:

"The Supreme Court has
...

To continue reading

Request your trial

VLEX uses login cookies to provide you with a better browsing experience. If you click on 'Accept' or continue browsing this site we consider that you accept our cookie policy. ACCEPT