Advice for Experts Facing Cross-Examination

by Steve Babitsky and James Mangraviti, Jr.

Steve Babitsky and James Mangraviti, Jr., of the Massachusetts consulting firm, SEAK, have written a book entitled, How To Excel During Depositions: Techniques For Experts That Work. They have graciously given us permission to reprint the following excerpt from that book. Although their tips are specifically concerned with answers to questions at depositions, most of their advice applies equally well to cross-examination.

This article was originally published in the summer 1999 issue of the Expert Witness.

Avoid Absolute Words

You are well advised to avoid, where possible, absolute words such as “always” and “never.” Absolute words are frequently an invitation to, and fertile grounds for, cross-examination by counsel. Counsel will attempt to damage your credibility by first getting you to make an absolute statement. She will then use counterexamples in an effort to show the falsity of your statement.

Don’t Elaborate or Volunteer

Volunteering information can be one of the biggest mistakes an expert makes at deposition. Generally, an expert should answer only the questions she is asked and not volunteer information. The volunteering of information will almost always result in new lines of cross-examination. It may also disclose information to which counsel otherwise never would have become privy.

Be Careful When Using Hedge Words

You need to be careful when using hedge words when expressing your opinion. Such words include “I guess,” “I believe,” “it seems,” “it’s possible,” and “I would say.” The only reason that you are testifying is to give an opinion. Hedge words and phrases can quickly undermine your opinion and are an invitation for additional cross-examination. Worse, counsel may be able to make a motion to have your entire testimony stricken because expert guessing is not allowed under the rules of evidence.


Q: That’s your “guess,” sir?

A: Well, what I meant to say, that it was my opinion that….

Lesson: The expert needed to avoid the hedge words. If he had an opinion he believed in, he should have stated it without employing the hedge words.


In answering questions honestly, you may have to make an occasional concession. If you make the concession graciously and move on, you will exude confidence, integrity, and flexibility. If, on the other hand, you doggedly refuse to give an inch, you may come off as rigid and partisan.

The most common error the beginning expert makes in a deposition is the failure to concede an obvious and irrefutable point out of misguided loyalty to his or her side of the case…. Quibbling over the possible exceptions or equivocating in some way helps no one.

“I Don’t Know”

If you are asked a question that you do not know the answer to, your answer should be, “I don’t know.” There is absolutely nothing wrong with this response if you genuinely do not know the answer to the question. There are probably thousands of questions that can be asked of experts in any discipline to which they have no answer. The more the expert hesitates or tries to avoid saying, “I don’t know,” the more emphasis is given to this “lack of knowledge” by the jury or fact finder. No amount of hesitation will bring the answer to you if you do not know it.


Q: If those wrist rests were unavailable prior to 1991, would you agree she had a higher probability then of being in a neutral position?

A: I don’t know. That’s an interesting question. I don’t know. I mean I guess that’s my answer, I don’t know. But I think the wrist rests certainly emphasizes, even though you have the Ridyard’s ergonomic assessment of 1994, if Miss Sanford and/or her supervisor were trained, that would not have been a product of choice.

Lesson: If you allow yourself to get flustered, your lack of knowledge will be emphasized to the jury. The expert in this example would have been better served by replying, “I don’t know” and then sitting quietly and waiting for the next question.

“I Don’t Recall”

When asked about a fact, situation, or occurrence that you honestly do not remember, the best answer is, “I do not remember” or “I don’t recall.” This is only an appropriate answer when you honestly have no recollection. Perjury ramifications aside, an endless string of “I don’t recalls” (or even one that may seem hard to believe) may tend to damage your credibility. If your response is that you do not recall, counsel may then attempt to refresh your memory. This is permissible under the rules of evidence.

Beware of Open-ended Questions

You should be cautious when dealing with open-ended questions. These questions invite long, rambling answers. Counsel may be trying to get you to volunteer information not called for by the question. If you do volunteer information, it is likely that this information will be used against you during cross-examination. You should therefore answer open-ended questions as concisely as possible, being careful not to provide information that was not asked for. Experts are better served by brief, succinct replies to open-ended questions. If counsel has follow-up questions, let her ask them. Don’t do the lawyer’s job for her.

Avoid Slang

Avoid slang expressions when replying to questions. When they are transcribed and read back to a jury, these expressions diminish the value of your reply and can make you sound almost illiterate. Most slang expressions slip from experts unintentionally. To avoid making such a slip, you will need to maintain your concentration and focus.


Q: Now, sir, you were asked on direct examination about the history that you took from Ronald Evans, right?

A: Uh-huh.

Q: And the history is the story that he tells you, correct?

A: Uh-huh.

Q: Is that a yes?

A: Yes, it is

Q: Are you familiar with an organization called M.O.R. Incorporated, sir?

A: Nope.

Lesson: The expert’s use of slang cheapens his testimony and diminishes his credibility.

Counsel’s “Bumble and Fumble” Gambit

Do not help counsel when he is apparently bumbling or fumbling with some type of technical question. Experts are frequently tricked into volunteering key information by such real or feigned ignorance. Let counsel bumble or fumble all they want. Remember, you are there to answer questions, not to assist counsel in framing them correctly.

Yes or No Responses

If counsel asks for a yes or no response and you can answer the question with a yes or a no, endeavor to do so. If counsel attempts to insist on a yes or no answer to questions that cannot be answered in that fashion, you can state, “I cannot answer that question with a yes or no reply.” It will then be up to counsel to either let you explain your answer or rephrase his question.

What to Do When You Make a Mistake

Expert witnesses are not expected to be perfect. During a long and arduous deposition, you may misspeak or make a mistake or error. If you do make a mistake, you should correct the error on the record as soon as you recognize your error. “I want to correct a statement I made a few minutes ago. I stated that the 1991 EMG was related to the surgery. That is incorrect.” Counsel may quickly challenge you on your mistake before you have an opportunity to correct it. In that case, admit your error graciously. What you want to avoid after making a mistake is making the matter even worse by your inability or unwillingness to admit the mistake. This could make you look biased. If you discover your mistake after the deposition concludes, notify counsel and correct the deposition transcript when it comes for your signature.

“I Don’t Know, But…”

As an expert witness, you are under oath to tell the truth. You should not speculate, but should testify with a reasonable degree of certainty. At trial, many experts do not practice this principle and, in fact, speculate freely. One of the most common forms of speculation by experts at trial is the “I do not know, but…” reply. It is usually a mistake to use this response. First of all, if you don’t know, then any information you provide after the “but” is mere speculation. Secondly, you may volunteer damaging information after the “but.”

The simple, direct, and best response is, “I don’t know.” The throwaway statements that come after the “but” or “I don’t know” reply help counsel by providing him or her with additional information. This type of reply frequently results in new lines of inquiry and detailed questioning by counsel.


Sophisticated counsel may attempt to trap the expert witness by the use of the word hope. If you inadvertently agree with a characterization, you may allow the lawyer to successfully call into question the reliability of your opinion. When you are confronted with an “And you are hoping…” question, it may be best to actively refute that characterization. Remember that when you are passive and agree to an attorney’s characterization or mischaracterization, you are in effect letting the attorney put words in your mouth.

Refusal to Speculate

You should not permit yourself to be tricked, cajoled, or forced into speculating when answering questions under oath. There is nothing wrong with the response, “I’m sorry, but I’m not going to speculate on that.”


Beware of the use of the word possible. Testifying that something is merely “possible” is most likely legally insufficient. If your opinion is only a mere possibility, the judge will most likely not allow it to be presented to the jury as evidence.

“I Guess”

As an expert, you are testifying under oath. Your testimony will help resolve the rights and liabilities of parties who are involved in a legal dispute. Accordingly, there is no place for you to guess. Experts are well advised to leave the guessing to financial advisers, political pundits, and meteorologists. Your “guesses” are not admissible in evidence. Guessing can only hurt your credibility. It should be avoided.

“I Don’t Understand the Question”

You need not answer questions that you do not understand. If the question propounded to you is confusing, the preferred answer is, “I don’t understand the question.” Exercise caution in giving “I don’t understand” replies to avoid answering questions improperly. For example, if you are one of the leading computer experts in the world and have testified that you didn’t understand a question about a browser, it is likely that your credibility will be impaired. You must answer truthfully and are permitted to answer, “I don’t understand” only when that is the actual case.

Compound Questions

Frequently, attorneys attempt to confuse the expert at deposition by asking compound questions; that is, two questions combined. Sometimes the question is asked in a stream of consciousness manner that is difficult to comprehend, let alone answer accurately. When faced with such questions, appropriate responses include: “Counsel, you have asked several questions. Can you simplify the question so I can answer it accurately?” and, “Counsel, I’m sorry, I don’t understand the question. Could you please rephrase it?”

“I Assume”

You should not make unfounded or unsupported assumptions in an attempt to answer a question. If you can’t answer or don’t know the answer, say so. Expert witnesses need not and should not make unsupported or unsubstantiated assumptions in an attempt to answer questions at deposition.


Q: Does the computer program have the capability of printing out a master index of all of the crash tests?

A: I don’t know, but I would assume that some computer person set this system up and can go in and generate a list of all of the data in there….

Lesson: Assuming in a case like this is akin to guessing and should be avoided. A better answer might have been, “I don’t know.”


Steve Babitsky is President, and James Mangraviti, Jr. is vice-president, of SEAK Inc. SEAK is a provider of “inter-disciplinary seminars, distance learning resources, and publications” in the areas of workers compensation, occupational health and, medical-legal issues. Further information about them can be obtained from their excellent website: or telephone 508-548-7023.