The New Daubert Standard For Experts in Wisconsin Courts

Note from Jerry Deschane, CAE, WBA Executive Vice President:
The Wisconsin Legislature has adopted new rules for expert evidence that will help protect builders from unfair or outrageous claims in court. Wisconsin joins most other states in now following federal rules for admitting expert witness testimony. Among other things, the new standard requires the evidence to appear to be reliable. For decades, Wisconsin’s only requirement is that the evidence must be relevant. Although they are close in the dictionary in the real world, there are miles between when an opinion is “reliable,” and when it is “relevant.” An example would be that my opinion about the Packers’ defensive scheme may be relevant, but if I were Coach McCarthy, I wouldn’t rely on it!

The new rules apply to any new lawsuits going forward, and should help builders defend against damage claims where the “expert testimony,” is more a matter of opinion than scientific fact.

Author: Patrick Fiedler, Axley Brynelson LLP.
In January 2011, the Wisconsin Legislature passed various tort reform measures embodied in 2011 Wisconsin Act 2. Of particular import to trial lawyers is the modification of §§ 907.01, 907.02 and 907.03 of the Wisconsin Statutes. These sections address opinion evidence for expert and lay witnesses. Act 2 conforms Wisconsin law regarding the admissibility of opinion evidence of expert and lay witnesses to Federal Rules of Evidence 701, 702 and 703. These modified rules of evidence apply to actions or special proceedings commenced on or after February 1, 2011.

Prior Law

Prior to the passage of Act 2, the standard for admissibility of expert opinion evidence was the relevancy test. Watson v. State, 64 Wis. 2d 264, 273 (1974). Admissibility of scientific evidence was not conditioned on its reliability. Rather, scientific evidence was admissible if: (1) it is relevant, § 904.01, (2) the witness is qualified as an expert, § 907.02, and (3) the evidence will assist the trier of fact in determining an issue of fact, § 907.02. State v. Peters, 192 Wis. 2d 674, 687-88 (Ct. App. 1995), citing State v. Walstad, 119 Wis. 2d 483 (1984). This standard differed from the reliability standard used in federal courts and some other state courts.

Current Law

The reliability standard is often referred to as the Daubert standard and is the product of three U. S. Supreme Court decisions, Daubert v. Merrell Dow Pharmaceutical, Inc., 509 U.S. 579 (1993), General Electric Company v. Joiner, 522 U.S. 136 (1997), and Kumho Tire v. Carmichael, 526 U.S. 137 (1999). In 2000, the U.S. Supreme Court amended FRE 701 and 702 to reflect the holdings in these three cases. With the passage of Act 2, Wisconsin now follows the Daubert standard.

There are three requirements for expert opinion evidence to be admissible under § 907.02(1):

  1. The evidence must be relevant;
  2. The expert must be qualified; and
  3. The expert’s opinion must be reliable.

The trial court determines reliability and in order for the opinion testimony to be admissible, the court must be satisfied that:

  1. The testimony is based on sufficient facts or data;
  2. The testimony is the product of reliable principles and methods; and
  3. The witness has applied the principles and methods reliably to the facts to the case.

All three questions are preliminary issues of admissibility for the judge under § 901.04(1), and the standard is a preponderance of the evidence. Bourjaily v. United States, 483 U.S. 171 (1987). Of interest is that § 907.02(2) prohibits testimony of an expert witness where any compensation of the expert is contingent on the outcome of the claim or case.

Obviously, there is no Wisconsin case law addressing this new reliability standard and Wisconsin courts are not bound by federal decisions or decisions in other states. What may be of assistance to Wisconsin courts in these early stages of determining reliability is a checklist. The Federal Committee Note on Rules – 2000 Amendment includes a non-exclusive checklist for trial courts to use in assessing reliability of expert testimony:

  1. Whether the expert’s technique or theory has been tested.
  2. Whether the techniques or theory has been subjected to peer review and publication.
  3. The known or potential rate of error.
  4. The existences and maintenance of standards and controls.
  5. Whether the technique or theory has been generally accepted in the scientific community.
  6. Whether experts are proposing to testify about matters flowing naturally and directly out of research they have conducted independent of the litigation, or whether they have developed it for purposes of testifying.
  7. Whether the expert has unjustifiably extrapolated from an accepted premise to an unfounded conclusion.
  8. Whether the expert has adequately accounted for obvious alternative explanations.
  9. Whether the expert is being as careful as he would be in his regular professional work outside his paid consulting.
  10. Whether the field of expertise claimed by the expert is known to reach reliable results for the type of opinion the expert would give.

This checklist, while not binding on Wisconsin courts, is helpful in analyzing and making a determination as to admissibility.

The modification of § 907.03, “Bases of opinion testimony by experts” includes the identical language as before:

“The facts or data in the particular case upon which an expert bases an opinion or inference may be those perceived by or made known to the expert at or before the hearing. If of a type reasonably relied upon by experts in the particular field in forming opinions or inferences upon the subject, the facts or data need not be admissible in evidence in order for the opinion or inference to be admitted.”

and adds the following language:

“Facts or data that are otherwise inadmissible may not be disclosed to the jury by the proponent of the opinion or inference unless the court determines that their probative value in assisting the jury to evaluate the expert’s opinion or inference substantially outweighs their prejudicial effect.”

This additional language may open a door that was previously closed to inadmissible evidence. A lawyer objecting to this evidence should ask for a limiting jury instruction in the event that the objection is overruled.

The law remains that expert opinion testimony must still be expressed to a requisite degree of certainty although not necessarily in specific language. E.g., “Do you have an opinion to a reasonable degree of professional certainty (probability)? Pucci v. Rausch, 51 Wis. 2d 513, 517-520 (1971).

Section 907.01 sets forth the rule for admissibility of opinion testimony by lay witnesses. As was previously the case, a lay witness may give testimony in the form of an opinion or inference if it is rationally based on the perception of the witness, and it is helpful to a clear understanding of the witness’s testimony or the determination of a fact in issue. The new requirement is that the opinion or inference must not be based on scientific, technical, or other specialized knowledge within the scope of a witness under § 907.02(1) [expert witness].

In analyzing and making rulings as to admissibility of opinion evidence under this new Daubert standard, it appears that Wisconsin courts must first determine whether the proposed opinion evidence is lay testimony or expert testimony. If it is lay testimony, it must be based on personal knowledge; if it is expert testimony, it must be “reliable” specialized knowledge.

Determination of admissibility of evidence remains an exercise of discretion by the trial court. See State v. Yang. 2006 WI App 48, 290 Wis. 2d 235 at ¶ 10:

“A trial court’s decision to admit or exclude evidence is a discretionary determination that will not be upset on appeal if it has a ‘reasonable basis’ and was made ‘in accordance with accepted legal standards and in accordance with the facts of record.’

Whether a trial court’s decision to admit or exclude evidence comports with legal principles, however, is a matter that we review de  novo.”

Wisconsin trial courts will be faced with the question as to what constitutes a proper record upon which to exercise this discretion and make a ruling as to admissibility. Likewise, when is the proper time for the court to have a hearing on any Daubert issues? No judge wants to be surprised or to keep a jury waiting. A number of Wisconsin courts have already included the handling of Daubert matters in their scheduling orders. Typically, those orders require counsel to name their experts and to give a summary of the expert’s testimony by a date certain. Opposing counsel must then enter a timely Daubert objection. Depending on the type of expert opinion, it is most likely that the court will do one of the following :

  1. Conduct a pretrial hearing without testimony based on affidavits, deposition transcripts and briefs; or
  2. Conduct a pretrial evidentiary hearing featuring the expert’s testimony.

Since the ruling by the trial court is an exercise of discretion, it is incumbent upon counsel to make a full and complete record before the trial court. Waiting until appeal to make a good record is guaranteeing failure because the appellate court neither conducts factual hearings nor makes findings of fact.


Any lawyer who appears in Wisconsin courts must become familiar with the changes in evidentiary law relating to expert witnesses and lay witnesses. These changes apply to all types of civil and criminal proceedings. See § 911.01(2). The Daubert standard for expert opinion testimony requires the judge to determine not only relevancy but also reliability. The Federal Committee Note on Rules – 2000 Amendment checklist, while not binding precedent, may provide helpful guidance to Wisconsin trial courts in assessing reliability of expert testimony. Finally, the law now makes a clear distinction between lay opinion testimony and expert opinion testimony. Lay opinion testimony must be based on personal knowledge; expert opinion testimony must be “reliable” specialized knowledge.

For more information about the new Daubert standard in Wisconsin, contact Patrick Fiedler at 608.283.6753 or

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