Expert Witness Deposition: 28 Winning Strategies for Experts

Deposition is a vital pretrial step where opposing parties are trying to gather as much information as possible from a proffered witness.

Joseph O'Neill

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— Updated on August 27, 2021

Expert Witness Deposition: 28 Winning Strategies for Experts

As an expert participating in deposition, you will be asked about your written expert report, presented opinions, and methodologies. Deposition is also where opposing counsel may attempt to discredit your credibility or undermine your report ahead of trial testimony.

Fortunately, with foresight and ample preparation with your hiring attorney, it’s possible to sail smoothly through your first deposition. For a deep dive into the expert experience during deposition, we went to the source: deposition veterans. Read on for 28 of the best pieces of advice for nailing a deposition directly from experienced consultants, attorneys, and legal professionals.

1) Do Your Case Homework

Advice from Forensic Engineering Expert E-046811:

For both the attorney and the expert:

  1. Jointly review materials beforehand.
  2. Jointly review the pros and cons of the different positions.
  3. Understand the objectives of the various parties, including your own.
  4. Understand each other’s limitations.
  5. Be sure their calendar is clear for the evening should questioning go over time.

For the expert:

  1. Do not allow yourself to deviate from your opinion unless there is new information presented (as can often happen in questioning, which explores alternative scenarios rather than actual facts).
  2. Tell the truth, even if it is not in your client’s favor. There is no need, however, to embellish. You are not there to “win” but neither are you there to “lose”. That is the attorney’s job.
  3. Remember it is only a job. Your answers need to remain ethical and professional.
  4. The attorney is an advocate and their approach to questioning, regardless of the questions asked, tone of voice, or attorney behavior is not a personal issue.
  5. Answer the question asked.
  6. Do not lead the questioning with the answer.
  7. “Yes” and “no” are both completely sufficient answers for a “yes” or “no” question.
  8. “I don’t know” and “I do not recall” are also perfectly acceptable answers if true. So is “that was not part of my scope of work.”
  9. Do not allow yourself to be rushed to answer.
  10. Read documents that are referenced in questions when necessary where these are available, such as documents entered as exhibits (there are unlikely to be any others). Read them carefully before answering regardless of the time needed.

2) Know Your State’s Standards

Advice from Cardiology Expert E-403456:

Be prepared, focused, listen carefully to the questions, and maintain good eye contact with the audience. You also need to know the national, state, and regional standards for the issues at hand. Stay calm regardless of questions, and if the question is multilayered, either answer with intention to each layer or better, ask that the question be restated. And know your material and case very well.

3) Answer the Question Asked

Advice from a seasoned legal nurse consultant (LNC):

Be sure to answer only the question asked. Don’t elaborate—let the attorney walk down the pathway of further questions.

 4) Keep Cool

Advice from Life Care Planning Expert E-000286:

Remember, you wouldn’t be there as an expert if you didn’t know what you were doing, and you know more about your subject matter than the opposing counsel. You can communicate confidence while still holding your cards relatively close to your vest. You can maintain control by recognizing attempts to trap you into speculation or oversharing and resist them by being boringly brief.

When they ask you the same question over and over in an attempt to get you to say something different, repetition is your friend. Be familiar with the documents you know opposing counsel already has in hand. Dress comfortably (but no jangly jewelry to make a racket in the court reporter’s recording). Read the transcript carefully and make necessary corrections; I’ve never seen one that was 100% accurate. Last, remember what it says on the mayonnaise jar: Keep cool, do not freeze.

5) Pay Attention to Objections

Advice from a celebrated personal injury attorney:

Pay attention when the attorney who retained you objects to a question. This usually means the question posed is a trick, or purposely crafted to confuse you or impeach you. Take the time to think about an answer to a potentially improper question.

6) Prep the Day Before

Advice from a law enforcement expert:

The attorney and expert need to be on the same page. I always meet with my attorneys the day before the deposition. If the attorney doesn’t have time or refuses to meet, I will normally not work for them again.

7) Stay in Control

Advice from an expert entertainment consultant:

It is imperative to meet with the attorney in advance for prep and to understand your anchor hypothesis. If your main hypothesis is strong, you can always come back to that in all your responses. And of course, listen to the question and answer only the question being asked. You can get a sense from the attorney representing you (how they object to the line of questioning) as to whether the opposing attorney is trying to trip you up. They may continue to ask you the same question in a variety of ways to get you to answer the way they want.

Listen closely, take your time, connect with your attorney non-verbally, and control the pace of the deposition. If you need to stop a line of questioning that is onerous, ask for a glass of water, take a bathroom break, or ask to speak to your counsel. You, as the expert, can and should be in control. Remember, the opposing attorney is only doing their job in questioning you. It is not personal.

8) Communicate with Your Hiring Attorney

Advice from a railroad safety consultant:

My first expert witness deposition was a fiasco. I met my attorney on the morning of the deposition 30 minutes after the appointed meeting time; he had been sitting upstairs chatting with the other attorney. All the information I had prior to the deposition was nearly 800 pages of badly written depositions to peruse. Individual depositions had pages missing, some were missing altogether, and the opposing attorney was the typical smart-mouthed individual who proclaimed at the beginning of my deposition that I would not qualify as an expert witness for the case.

It turned out that he was correct, I did not qualify. My attorney said nothing during my deposition and just let me sink slowly into the sunset without voicing an opinion or even a whimper. He never asked me any questions, he never discussed the case with me beforehand, and he didn’t even ask the pertinent questions regarding Federal Regulations that were violated during the treatment of the injured party. This soured me completely regarding any testimony for any attorney and I have since relegated myself to the training and consulting for start-up operations for plant railroads and short line operations.

9) Tell the Truth

Advice from a meteorology expert:

Here are a few keys that I always try to follow:

  1. Make sure that you can explain all of your conclusions and opinions.
  2. Don’t waver on your opinion. If you start to change your opinion at that point, then you will be opening yourself to having your conclusions/report ripped apart or, worse, you can be discredited as an expert.
  3. Tell the truth. It may seem like a no-brainer but you don’t want to answer a question that you think you know the answer to only to be proven wrong. It can be ok to say that you aren’t sure and will have to check after the deposition.
  4. Stick to answering the question you were asked. Don’t offer any more information than you were asked about.

Remember, it is an attorney’s job to be very thorough and find any weaknesses in your opinions.

10) It’s Not Personal

Advice from Civil Engineering Expert E-167551:

Try to remember not to take rough questions personally, and keep your wits about you if you start to feel as if counsel is attacking you. Counsel’s job is to discredit your testimony, and unless you appear to be a smart ass, jurors typically don’t react favorably to personal attacks.

Furthermore, don’t argue even if counsel tries to start something. Most of the attorneys I’ve run into are decent people who have a job to do for their client, but occasionally you run into an aggressive jerk or someone who wants to be intimidating. Don’t fall into the trap.

11) Prepare with Your Hiring Attorney

Advice from a social work expert:

Make sure to prepare with the hiring attorney—this is critical. The only time I had trouble with a deposition was when the opposing counsel made a concerted effort to tire me out. He used several hours on my CV alone. Unfortunately, my attorney was quite new, and opposing counsel actually bullied and manipulated him. I stress that this is unusual. Most of the time my attorney and I are in tune and opposing counsel is not making an effort to be obnoxious.

12) Beware of Hypotheticals

Advice from a forensic locksmith consultant:

Watch out for “circular” questions and hypotheticals. The opposing attorney may try to undermine your position by leading you on a series of questions that will lead you to a contrary conclusion if you don’t see what they’re trying to do.

13) Listen Carefully

Advice from Discrimination, Harassment & Negligence Expert E-009510:

Listen very carefully to each question to determine if any words the opposing counsel uses in a question will throw the core of your testimony out of context—such words may be: always, never, should have, and others like the ones listed. Use good eye contact. Remember that everything you have written in books, book chapters, and articles can be used to discredit your testimony.

14) Make Sure You’re Qualified

Advice from an engineering expert:

  1. Be sure you are qualified and adequately prepared to discuss the subject matter at hand.
  2. Be honest and truthful in your answers.
  3. Be calm and deliberate in your responses – see #1.
  4. Don’t try to outsmart or outmaneuver opposing counsel.
  5. Enjoy the experience – attorneys are people too!

15) Stay Consistent

Advice from Aerospace Propulsion System Expert E-208967:

Prior to the deposition, the expert witness will review all pertinent case information and compose a report. The opposing counsel will review the background/qualifications of the expert witness and will question the facts contained in the report. The responses should be stated in simple laymen’s terms. It is important to stay on-topic. At no point should the expert witness offer any opinions or make any statements outside their area of expertise.

Avoid appearing flustered by the questioning. Request a rephrasing of the question if it is unclear. The expert witness may be asked a question and requested to give a simple yes or no answer. If further explanation is required, however, politely decline to answer the question, unless a more granular response is permitted. Do not answer a question that is not fully understood, and do not offer more information than what would adequately answer the question. The same question may be asked in several different ways during the course of the deposition. Provide consistent responses and maintain your composure, no matter what! Request a break, if necessary. The expert witness who has done their homework and thoroughly understands the issues will be fully prepared for a deposition!

16) Stay Neutral

Advice from Accident Reconstruction Expert E-008914:

Try to keep emotions out of the deposition and recognize when an attorney is trying to get you frustrated or angry. This distracts you from your science and analysis.

17) You’re Not an Advocate

Advice from a forensic consultant:

I try to keep in mind that I’m not there as an advocate for a party or position, but rather I am there to provide information and opinions based upon my experience and training within my area of expertise. A “successful deposition” is one in which I have clearly and completely relayed my opinions and their bases.

18) Don’t Try to Steer

Advice from Financial Arbitration and Investment Expert E-010992:

As an expert, a deposition is not the place to be thorough, comprehensive, or detailed in your testimony. Your goal is to give away as little as possible and if opposing counsel seems to be off base in his questions, let him do it and do not steer your deposition testimony back to your opinions and ideas. Remember this is “discovery” and the less you explain, and the less you clarify your testimony, the more flexible you can be in the trial.

A deposition is exactly the opposite of the hearing where your report or opinion is substantiated. Never volunteer answers to questions you want to be asked, or lead the examiner to drill down on your answers. Do not educate the opposition or lead them to finite conclusions they can attack. Be as general as possible. Nothing you say in a deposition is evidence until offered to impeach your testimony in a hearing. It is not the expert’s job to educate or explain their position, rather it is the opposing counsel’s job to elicit as much impeachment testimony as possible.

Furthermore, by the time you’re deposed, you should have the opposing expert’s report to review. Depending on the content of the opposing report, do your best not to disclose your opinions and criticisms of it, a tendency that’s hard for most experts to do. Depositions are a hide and seek exercise, not a classroom full of eager students needing to be educated.

Finally, as an expert in a hearing, I am an advocate for my opinions and analysis, not for the client. In a deposition, I am not an advocate at all, merely a cryptic source of information that opposing counsel will try to wring out of me through examination. If your deposition testimony is anything like your hearing testimony in detail and thoroughness you’ve probably failed your test. In depositions, yes or no is the preferred answer, getting you to explain is the opposing counsel’s responsibility, not yours to volunteer.

19) Understand the Case Approach

Advice from a utility user rate consultant:

Demand preparation and rehearsal from the hiring attorney. The hiring attorney usually knows what major opinion can help turn the case to their client’s favor and should emphasize that issue, and how to express that response.

In addition, I recommend these three rules:

  1. Be well informed of the subject
  2. Be truthful
  3. Be prepared

Those will always get you through a deposition (or trial) with professionalism.

20) Take Your Time

Advice from Mechanical Engineering Expert E-633939:

When asked a question by opposing counsel, pause for a moment before you answer. This is a good tactic particularly for those that have limited deposition experience. It gives the expert time to compose their answer and give a reasoned, concise response. It also gives your retaining attorney time to object to the question if appropriate. The resulting exchange between the opposing attorneys may be helpful to the expert in responding to that or follow-up questions.

21) Remember You’re the Expert

Advice from Interactive Media Expert E-652340:


  • Stay calm. Getting worked up (emotionally or even intellectually) undermines your credibility.
  • Be prepared with your evidence, not your testimony.
  • Practice with an attorney, as realistically as you can (obviously with confidentiality).
  • Expect to be occasionally rattled. This happens to the best of us. Take a few deep breaths, ask for a little time if you need it, and re-focus on your evidence
  • Remember you’re the expert: They’re trying to get information from you, not the other way around


  • Volunteer too much information. Usually comes from nervousness or not listening carefully to the question(s)
  • Get emotional, never take a line of questioning personally.
  • Try to anticipate questions or “lines of attack”. Think of your evidence, not where counsel might be going.
  • Try to say what you think counsel (or a judge) wants to hear.

I find these are particularly applicable to new or inexperienced witnesses; I speak from experience!


22) Focus on Your Expert Report

Advice from a real estate appraisal consultant:

Thorough research leading to a well-prepared report is the key to success. No matter how hard we may try, no matter how thorough our analysis, no matter how many times our report may be reviewed, it is exceptionally challenging to write the perfect report that addresses all issues without error. Even very small errors of fact can be damaging.

As such, as soon as you become aware that you are going to be deposed, reread and re-review your report critically, rechecking all data and statements of fact. Have a colleague you can rely upon do the same. You need to approach the deposition assuming that opposing counsel will have engaged their appraiser to review your report looking for any error of fact, or weak analysis, which can assist in discrediting your work. Should your re-review uncover any areas that may cause you concern, you will at least be aware of the potential issue(s) and have the time necessary to prepare a response in advance of being deposed.

23) Research the Opposition

Advice from a property tax advisor:

“Know your enemies and know yourself, and you will not be imperiled in a hundred battles.”

  • Sun Tzu

Before a deposition, I research the opponent’s attorney and the opponent’s expert (and their appraisal, if available). I want to know the attorney’s style (aggressiveness versus friendly) and I want to know the attorney’s competency in property valuation. Even though the opposing appraiser/appraisal usually isn’t part of a deposition, knowing the content or anticipating the variances from my analyses is important in understanding where the attorney will seek concessions or acknowledgment of weaknesses.

I was deposed in a utility property case several years ago. I had encountered the opponent’s attorney about five years earlier. He had an aggressive litigator’s style and had speculated at our first meeting that people he deposed or examined might run him over when he exercised in the city. He did not remember me. When I shook his hand, I told him I was surprised to see he was still alive. He was flustered, then embarrassed when I recalled his statement from five years ago. My attorney laughed, and even the stenographer smiled broadly. Needless to say, he was completely off his game during that session.

24) Remember Your Role

Advice from a fine art appraisal expert:

One of my personal stories includes flustering an opposing attorney famously, which my client attorney enjoyed but said later, “If you ever do that again I’ll never use you again”. It was sage and we occasionally still recall it as a part of my understanding of our roles.

My only addition to the above inputs for experts is to realize you are a single tool in the kit for the litigator, among many others. Stay sharp and be sure of the wielder. Also charge for depositions by the day, not the hour, in advance and irrevocably.

25) Don’t Let an Attorney Intimidate You

Advice from a real estate appraisal expert:

Never let an attorney intimidate you. Even when it gets ‘testy’, never let them see you sweat. Keep your calm and let just give them more rope—works every time. You know you’ve done a great job when after the case is completed and the opposing attorney calls to engage you as an expert on another case. It’s the ultimate compliment.

26) Provide Context When Appropriate

Advice from a valuation and economic consultant:

In depositions, not at trial, you may and should, depending on the judge/forum, qualify your answers very carefully and consider selectively “over-answering” for completeness.

You really have to listen to the question and not “buy into” the premise. Sometimes, attorneys and judges do not understand this concept. They expect a “yes or no” question to be answered yes or no with no explanation. The problem is that just yes or no answers can be a recipe for your testimony to be used as a sound bite and your opinions and the bases for your opinions misrepresented. Good attorneys and judges understand that a yes or no answer that may be misinterpreted or misleading may be qualified. I have succeeded most of the time on this issue and gotten away in many cases with “over-answering” by being prepared, telling the truth, knowing the subject matter, and staying in my box of expertise, but there are those times when I have been less successful.

Most courts and attorneys come to appreciate the frankness, completeness, and transparency of an expert confident and comfortable with his/her opinions and willing to explain and defend them; but some are not. There is a lot of hostility to experts, particularly in certain courts and before certain judges.

Additionally, never assume that the trier of fact or opposing counsel will understand (or want to understand) what is being said. Many attorneys are looking for sound bites in a deposition that they can use, twist or even misrepresent, especially if on the “wrong side”.

27) Keep Documents In Hand

Advice from a nursing consultant:

If documents are involved, have them either in hand or reference numbers. Have any applicable policies and procedures in hand.

28) Be Well Rested

Advice from a fine art appraisal expert:

The important thing to remember is that there are three primary reasons for a deposition: Allowing the opposing attorney to get a sense of your ability as a witness, seeing how well the perceived weak points in your appraisal are defended, and trying to generate responses that could be used to discredit your testimony at trial.

So know your report and the data thoroughly. You should be looking for potential weak points as you prepare the analysis and see if there is sufficient data or whether you need to change that section—this is done long before the report is complete and the final conclusion is reached. Take your time answering questions, and think out your answers at the deposition. Do not be afraid to ask for a break for the restroom.

Above all be sure you are well-rested before the day of the deposition, there is a reason pilots and truck drivers have limitations on how long they can work before they need to stand down and rest.

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