Daubert test

Make Sure Your Expert’s Opinion is Reliable

Posted by David Adelstein on February 15, 2018
Uncategorized / Comments Off on Make Sure Your Expert’s Opinion is Reliable

I use expert witnesses in many cases.  Many.  Experts are an important part of cases, particularly complicated disputes where an expert opinion is absolutely warranted. 

But, as I have discussed in prior articles, an expert’s opinion needs to have a foundation of reliability, which is governed by the Daubert standard.  Without ensuring that an expert’s opinion is reliable, then parties will hire the Joe Blows of the world, pay them a minimal dollar amount, for an outrageous, unsupported, and unqualified opinion.  This, of course, provides no value.  Hence, the Daubert standard or test “requires that ‘[t]he testimony is based upon sufficient facts or data’; ‘[t]he testimony is the product of reliable principles and methods’; and ‘[t]he witness has applied the principles and methods reliably to the facts of the case.‘” Sanchez v. Body & Soul Retreat, LLC, 43 Fla. L. Weekly, 43 Fla. L. Weekly D359b (Fla. 4th DCA 2018) (quoting Fla. Stat. s. 90.702).  If the opinion is not reliable, it is not admissible.

In Sanchez, the defendants sought to use an expert doctor.  However, the doctor was going to render an opinion based on a twenty minute exam of the plaintiff.  He reviewed no pre-incident photographs of the plaintiff before an important event at-issue to determine the plaintiff’s pre-incident condition.  He further made improper assumptions and inferences based on his review of medical records; however, his assumptions were not factually supported by the medical records, i.e., they were speculative.  

Based on this, the plaintiff moved in limine to preclude this doctor’s expert testimony and the trial court granted the motion in limine, which was affirmed by the appellate court.  This meant the doctor was NOT able to render an expert opinion at trial, i.e., the defendant had no expert opinion to counter the plaintiff’s expert opinion.  His opinion did not pass Daubert’s test–the opinion was NOT based on any reliable methodology and was further based on factually unsupported assumptions.

If you are going to use an expert, make sure the expert is prepared and has the relevant information to render a reliable opinion.  This doesn’t mean the expert needs to review everything under the sun.  But, this does mean the expert needs to be in a position to render an opinion based on factually supported assumptions and reliable methodology. Paying an expert the bare minimum hoping that an expert can render an opinion on an elaborate or complicated issue can come back and backfire, as the defendant in this case learned. The expert may very well be the key to your claim or defense so take the time to ensure the opinion passes the smell test!!

Please contact David Adelstein at dadelstein@gmail.com or (954) 361-4720 if you have questions or would like more information regarding this article. You can follow David Adelstein on Twitter @DavidAdelstein1.




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Expert Opinion Testimony and Understanding Daubert’s Gatekeeping Test

Posted by David Adelstein on January 10, 2015
Evidence, Expert Testimony / Comments Off on Expert Opinion Testimony and Understanding Daubert’s Gatekeeping Test

Expert opinion testimony

Expert opinion testimony is an important aspect of complex civil litigation. Expert testimony assists in proving or disproving liability and damages. A credible and persuasive expert can make the difference in a case and retaining experts, generating expert opinions, and the manner in which expert opinions are presented should not be taken lightly.

Regarding expert testimony, Florida Statute s. 90.702 provides:

“If scientific, technical, or other specialized knowledge will assist the trier of fact in understanding the evidence or in determining a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training, or education may testify about it in the form of an opinion or otherwise, if:

(1) The testimony is based upon 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 of the case.”

Not all expert opinion testimony is admissible. Courts are required to employ a gatekeeping function to ensure that expert opinion testimony is reliable before that testimony is admissible. This way unreliable expert testimony is not considered by the jury.



Florida courts now apply what has been referred to as the Daubert test to determine the admissibility of ALL expert testimony. See Perez v. Bell South Telecommunications, Inc., 138 So.3d 492 (Fla. 3d DCA 2014). This test arose out of the United States Supreme Court’s decision in Daubert v. Merrell Dow Phamaceuticals, Inc., 509 U.S. 579 (1993) and has been the gatekeeping test applied to expert testimony in federal courts.   This Daubert test forms the basis of a court’s gatekeeping function regarding the admissibility of RELIABLE expert opinion testimony.

How does a party offering expert opinion testimony satisfy its burden of establishing the reliability of the testimony? Parties need to know this because it is common for parties to file a (Daubert) motion attacking the reliability of another party’s expert testimony.

The Eleventh Circuit Court of Appeal explained:

“Courts must engage in a rigorous inquiry to determine whether: (1) the expert is qualified to testify competently regarding the matters he intends to address; (2) the methodology by which the expert reaches his conclusions is sufficiently reliable as determined by the sort of inquiry mandated in Daubert; and (3) the testimony assists the trier of fact, through the application of scientific, technical, or specialized expertise, to understand the evidence or to determine a fact in issue.”

 Rink v. Cheminova, Inc., 400 F.3d 1286, 1291-92 (11th Cir. 2005) (quotation omitted).



The first factor focuses on the qualifications of the expert. The expert needs to have some qualifications in order to render his/her expert opinion. Sometimes, however, parties hire experts with minimal qualifications. Federal courts have found that this goes to the expert’s credibility at trial and not the admissibility of the expert’s opinion. See Feliciano v. City of Miami Beach, 844 F.Supp.2d 1258 (S.D.Fla. 2012). This means that the other party can impeach the expert’s credibility at trial based on the expert’s minimal qualifications in order to create the appearance that the expert is not a credible or reliable witness.



The second factor focuses on the reliability of the expert’s opinion. Just because a witness is qualified to render an opinion does NOT mean the opinion is reliable. A judge has a degree of leeway in determining the reliability of the opinion by focusing on certain nonexclusive factors such as “(1) whether the expert’s methodology can be tested; (2) whether the expert’s scientific technique has been subjected to peer review and publication; (3) whether the method has a known rate of error; (4) whether the technique is generally accepted by the scientific community.” Rink, 400 F.3d at 1292.

This second factor is the crux of the Daubert test. See Fla. Stat. s. 90.702.   To this point, Florida’s Third District Court of Appeal in implementing the Daubert test as its gatekeeping function stated: “‘a key question to be answered’ in any Daubert inquiry is whether the proposed testimony qualifies as ‘scientific knowledge’ as it is understood and applied in the field of science to aid the trier of fact with information that actually can be or has been tested within the scientific method.” Perez, 138 So.3d at 498.



The third factor focuses on whether the expert testimony will assist the jury (trier of fact) in understanding an issue in the case. Thus, the expert testimony needs to be beyond the understanding of an average lay person and must not potentially confuse or mislead the jury. See U.S. v. Frazier, 387 F.3d 1244, 1262-63 (11th Cir. 2004). Also, the expert testimony must be more than what lawyers can argue in their closing arguments. Id. at 1263.


Please contact David Adelstein at dadelstein@gmail.com or (954) 361-4720 if you have questions or would like more information regarding this article. You can follow David Adelstein on Twitter @DavidAdelstein1.

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