IP Law Essentials

What to Consider When Selecting an Expert Witness


This blog series has already introduced you to the experts you're likely to see in patent cases (seeExperts in Patent Cases: Who They Are and Why to Hire Them).Here, we build on that foundation with a discussion of who can be an expert witness and an exemplary checklist of considerations for selecting an expert witness:

  • Expertise in the subject matter. By definition, an expert must have "scientific, technical, or other specialized knowledge" that "will help the trier of fact." R. Evid. 702.
    • Technical Experts – Expertise in the specific technology at issue is ideal, but it is often the case that expertise covering the broader field or area of technology is sufficient. For example, although the WiFi standards encompass many different features, it is not uncommon for one expert to be able to opine on many aspects of such standards. It is also important that the expert would have qualified as a "Person of Ordinary Skill in the Art" at the time of the invention. This allows the expert to properly consider the invention in the context of the technology at the time. For example, an invention dating back to 2001 may require an expert who completed a technical degree and/or embarked on a technical career as of 2001.
    • Damages Experts - Expertise in financial issues including, but not limited to, accounting, economics, and/or licensing. For example, although not required, damages experts often are Certified Public Accountants or have an MBA and/or a Ph.D. in economics or similar specialty. The level of education or experience often depends on the complexity of the damages issues involved.
  • Testifying expertise. A testifying expert should, ideally, have both deposition and trial experience. Depositions and trials present different challenges and a nimble expert can adapt their style depending on the setting. An abundance of testifying expertise ensures that the expert knows how to defend their opinions, avoid traps, preserve flexibility for trial, and effectively communicate their opinions to the jury.
  • Conflicts. A potential expert should be carefully vetted to ensure their past will not come back to haunt you. Proper vetting should include, for example: (1) checking the expert's work and publication history, including their patents, if any; (2) reviewing the expert's speaking engagement and consulting history; and (3) considering other publicly available information to see whether the expert has ever been adverse to your client, taken a position adverse to your client's positions in the case, or taken a position adverse to the subject of their retention. For example, a defendant in a case regarding a feature that purportedly extends battery life would not want to retain an expert that previously opined that battery life is the most valuable cellphone feature.
  • Any exclusion of prior opinions. Ask the prospective expert whether any aspects of their opinions have been excluded for any reason, and investigate those incidents. For example, research case law and review the orders, if any, where the expert's opinions were excluded. Many long-standing experts have had opinions or portions of opinions excluded in the past, and if your case is not sufficiently distinguishable from those prior cases, you might want to find a different expert.
  • Recommendations. Talk with people who have worked with this expert and seen them in action before. This will give you insight into their working style (e.g., degree of reliance on assistants, interactions with counsel, drafting style of expert reports) and their testifying style. You will also learn about their strengths and weaknesses and whether they are a good fit for your specific case. Note: It may be useful to maintain a database of experts that have been retained on behalf of and/or adverse to your client, including attorney impressions of the experts, which may help narrow and hone your choices over time.
  • Cost. Experts are most active during expert discovery (i.e. writing their expert report(s) and being deposed) and trial (i.e. preparing for and presenting their opinions). As one would expect, more experienced experts usually charge higher expert witness fees. But, some cost savings are possible. For example, multiple defendants can share one expert and split costs in patent litigation, you see this most often with invalidity experts. You could also look to a less established expert, such as someone who has experience working behind the scenes assisting other testifying experts, or a professor at a local university who has the required technical expertise, but may not have as much testifying experience. Another option is to rely on (often-more economical) consulting experts to analyze source code or run tests, reducing the workload of the more-expensive testifying experts.

More questions? Contact the authors or visitFish's Intellectual Property Law Essentials.

Authors: Taylor Caldwell, Joanna Fuller