Helping Your Expert Thrive in the Hot Seat: Part One

Presenting effective expert witness testimony requires more than finding someone who can arrive at the correct conclusions; you must communicate those conclusions in a convincing way.  The rules of evidence and procedure can create disadvantages for unfamiliar experts and prevent them from being persuasive.

The goal of this three-part blog is to help attorneys communicate the constraints imposed on witnesses within the litigation setting, and to suggest ways for effectively communicating at deposition and trial, so that the expert can be a more persuasive witness. The first step is to guide the expert in forming opinions that will be clear, relevant, and defensible.

Crafting opinions with the jury in mind

Start by reminding the expert that the ultimate audience will be the jury.  They should draft their opinions from the perspective of the jury members who will receive the testimony or report as one part of a larger story.  This will help them put their opinions in context with the other evidence, and will also help them explain their opinions logically, starting with a broad view and going to a more detailed explanation.  If the opinions will be used to support or defend a summary judgment motion, let the expert know how they can state their conclusions so they are consistent with the appropriate legal standard and help them understand how that legal standard will apply in the context of each case.

Request a verbal discussion of preliminary findings before your expert finalizes their opinions in any written format.  This creates better understanding between you and the expert on important issues.  If the preliminary findings are unfavorable, the expert can remain a consulting expert, as opposed to a testifying expert, and their opinions will not be discoverable.  In state court, written reports are not required, and in fact, they can be excluded if opposed by the other side.  In federal court, experts who are retained to provide testimony in a case must provide a written report pursuant to Federal Rule of Civil Procedure 26(a)(2)(B) containing all of their opinions, the facts they considered, any exhibits used, a list of all cases where they have testified at trial or in deposition in the last four years, and all publications in the last ten years.

Narrowing assumptions

Assumptions are normally required to fill gaps for unknown variables or disputed facts involved in the case.  Tell the expert to make his/her assumptions as narrow as possible, based on a reasonable interpretation of the evidence.  It is helpful to provide ranges, but it is not necessary to account for every extreme.  Establish a range that is consistent with the evidence and does not weaken the expert’s level of confidence in their opinions.

To use a common example, think of a coefficient of friction, which must be determined for a skid mark analysis in an accident reconstruction.  There are published data describing the coefficients of friction for various surfaces under various weather conditions.  Establishing a coefficient for a particular case requires judgment on the part of the expert.  You may expect their judgment will be tested on cross-examination.  Let the expert know they should not fear making reasonable concessions.  Juries normally have the ability to understand when the cross-examining lawyer has left the range of what is reasonable, and those types of admissions will not lessen the witness’s credibility.

Your expert’s testimony must be found sufficiently reliable by the trial court to be admissible.  It is not necessary for him or her to testify as to any degree of certainty other than “more likely than not”, but the jury will appreciate knowing the degree of confidence they place on their own opinions.  If appropriate, the confidence level can be stated in terms of percentages, or in general terms, such as highly confident.  Make sure the expert stays within their comfort zone and does not stretch their opinions or exaggerate their confidence levels.

Avoiding speculation

Tell the expert to request additional information if they feel that they have inadequate or inaccurate information.  The opinions may be rejected by the jury if they determine the facts are different from those relied on by the expert.  Opinions that are based on inadequate or incorrect information are likely to be considered speculation, and may be excluded by the judge or disbelieved by the jury.  During the investigation and discovery phase of the case you should direct your expert to make their investigation as thorough as possible, and encourage them to think of avenues for obtaining information from all possible sources.

You may elect to provide your expert with partial information or make certain assumptions which may not be entirely consistent with all of the evidence, such as where some evidence is not admissible and you wish to keep from the jury, even though it might be otherwise relevant.  When you force assumptions upon the expert, check those assumptions against the evidence and consider the effect that the assumptions will have on your expert’s opinions.

Stay tuned for Part Two:  Defending Expert Opinions at Deposition.

About Steven D. Groth

I am a partner in the Litigation Group of Bose McKinney & Evans. My practice concentration is in transportation, business and personal injury litigation. I defend clients in the trucking industry against wrongful death and serious injury claims. I also represent businesses in connection with contract disputes, construction accidents and construction defect claims. In addition, I represent individuals and businesses against personal injury claims.
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2 Responses to Helping Your Expert Thrive in the Hot Seat: Part One

  1. Lauren McConnell says:


    Your comments are very helpful but one of the problems I often encounter is that experts, like attorneys, are in the business of selling a service. And while preliminary talks should address whether or not the expert could potentially give you a favorable opinion, they should also probe the expert as to how he would be able to reach that opinion. I.e. whether he will actually implement a reliable methodology to arrive at a conclusion and can predict what causes he will need to rule out and is candid enough to tell you the obstacles you will face. My experience is that an expert who can’t provide points to rebut or attack the foundation of opposing experts is usually all credentials and no applied knowledge. And rigorous probing of the experts preliminary conclusions (based of course on your brief version of relevant facts) that results in more questions by the expert or conditional conclusions is a tell tale sign they are an academic (maybe) but not adept in the field. I would be interested in your tips to weed out the salesman from the specialist.

    – Lauren McConnell

  2. stevegroth says:

    Lauren – I agree that you should probe the expert’s methods at the preliminary stage to make your own judgment on whether they will be subject to a Daubert attack. Obtaining referrals from attorneys you trust, along with asking the expert for references can help avoid the salesmen. If you are shopping for an expert in a new area without any referrals, feel free to audition more than one and go with the one you like. In my experience, expert search services such as those offered by TASA, and Westlaw yield good results and avoid the direct salesman dynamic.

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