Understanding the Daubert Test for Expert Witness Testimony

Let’s say that you have an injury case that needs an expert witness. You have an expert witness—someone preeminent, experienced, and with a resume that is certain to ensure that your expert is, in fact, qualified by the court as an expert.

But then your attorney tells you that the other side is trying to have your expert’s opinion disqualified, or they are asking the court to not allow your expert to say what he or she wants to say.

How can this be? Why would an expert not be able to render an expert opinion for the jury to hear?

Not All Testimony Gets Heard

It’s because there is a certain threshold requirement that scientific or technical testimony must meet before a jury can hear it.

The logic has always been that an expert can be very persuasive, and use very technical terms, and thus, carry a lot of weight with a jury. An expert could always come to court, say something totally outlandish or ridiculous, and a jury could believe him or her.

Scientific testimony has got to meet some objective standard, to make sure the jury isn’t basing its opinion on “junk science.”

At the same time, experts have got to be free to say, and courts and juries free to hear, scientific information that may not be readily accepted. Remember that there was a time that saying that nicotine was addictive in court seemed outrageous.  Juries should not just hear well established scientific opinions, but should be free to hear even less popular, but still scientifically valid expert opinions.

What the Daubert Standard Requires

To be admissible, the expert’s opinions and the data that the opinion rests upon must be generally accepted in the scientific community. It’s okay if the testimony is not widely accepted, or if other experts would disagree, or even if the testimony is theoretical.

So long as the data upon which it is based is sound, and comes from sound scientific methods, it meets the first part of the Daubert test. The data also must be sufficient; an expert cannot base his or her opinion on one test or one data set.

The data also must come from a valid scientific or technical source. Hypothetically, if an expert saw a video on social media, and based her opinion on that, the opinion would likely not be allowed. Scientific data, journals, studies, and similar writings or research, would suffice.

If the expert did his or her own testing, or relied on studies that have testing, the testing must be scientifically valid. There are ways to properly test theories, ideas and hypotheses that are and which are not, scientifically valid.

The last part of the Daubert test is to ensure that the scientific testimony is properly applied to the case. An expert’s opinion on how truck brakes stop a large truck, although scientifically valid, may not have any application in an accident case where there were no trucks involved.

Call the Knoxville personal injury attorneys at Fox Farley Willis & Burnette, PLLC, today for help with your personal injury case.

Sources:

tncourts.gov/rules/rules-evidence/702

casetext.com/analysis/how-to-use-an-expert-witness-effectively-in-tennessee-courts