Admissibility of Expert Testimony Under the Daubert Standard: The “Reliability” Factor

In May 2019, the Florida Supreme Court found the standard set forth in Daubert v. Merrell-Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993), would determine the admissibility of expert testimony in Florida. See In re Amendments to Fla. Evidence Code, 44 Fla. L. Weekly S170 (Fla. May 23, 2019). Under Daubert, the three main elements a trial court considers to determine admissibility
are: 1) whether the expert is qualified in the area of testimony; 2) whether the methodology used by the expert in formulating an opinion was reliable, and 3) whether the testimony would assist the jury in understanding the evidence and determining a fact in issue presented in the case. Out of these three elements, parties almost always challenges the reliability of an expert’s opinion. Thus, it is important to know what makes an expert’s opinion reliable in order for it to be
admitted at trial.

When questioning the reliability of an expert’s opinion, parties commonly attack the accuracy of an expert’s methodology and the credibility of the testimony. However, the Daubert standard “focuses on the reliability of the expert’s methodology, not the reliability of the expert’s data or underlying conclusion”; the accuracy of the data “goes to weight, not admissibility.” Gecker
as Tr. for Collins v. Menard, Inc., Case No. 16 CV 50153, 2019 WL 3778071, at *6 (N.D. Ill. Aug. 12, 2019). Instead, the main concerns relevant to the Daubert reliability element are whether the methodology has been tested, whether it has been peer-reviewed, and whether it is scientifically accepted. See Vitiello v. State, 281 So. 3d 554, 560 (Fla. 5th DCA 2019). These are the factors courts should consider when performing a reliability analysis. Courts are likely to find an expert’s testimony reliable if it is scientifically valid and based upon a peer-reviewed methodology. Issues with the credibility and accuracy of an opinion do not preclude the admission of the testimony. Rather, these issues should ultimately be left for the jury to decide. See Lapsley v. Xtek, Inc., 689 F.3d 802, 805 (7th Cir.2012).