20 Tips for Writing a Better Expert Report

As an expert witness, experience, knowledge, and specific qualifications are just the barrier to entry. In reality, an effective expert witness is much more than an impressive CV. She is an educator, able to distill the most complex facets of any case into clear insights that nearly anyone can understand. Succeeding as an expert witness

ByJoseph O'Neill


Published on January 20, 2015


Updated onJune 22, 2020

As an expert witness, experience, knowledge, and specific qualifications are just the barrier to entry. In reality, an effective expert witness is much more than an impressive CV. She is an educator, able to distill the most complex facets of any case into clear insights that nearly anyone can understand. Succeeding as an expert witness rests – above all else – on how well you communicate with your audience. Nowhere is this more important than when writing an expert report.

To help experts and attorneys better understand this vital skill, we asked veteran trial consultants to share their advice for writing expert reports over social media. What resulted was an in-depth conversation between experts and attorneys of all types, with advice pouring in from the United States, Canada, and the United Kingdom. Below, we’ve compiled some of the most useful insights from that conversation, with the goal of representing a diverse selection of specialty areas and experience.

American Experts

“In the introductory section list those items of your training and experience that specifically relate to the matter at hand, in essence, your direct and qualifying testimony, in order to limit a, perhaps non-neutral judge, from tossing your report on the basis of something you have omitted. Then imagine EVERY WORD of your report being used against you on cross…phew!

Keep it simple, so that anyone could understand what you are telling them. The first thing I always submit is my Curriculum Vitae. That tells the lawyer where I have been and what he can expect of me. In 28 years I have developed 27 pages. I have only one rule to follow and stay within those bounds. Rule 702 is the strongest undeniable rule. If you can get past that rule you can go anywhere.”

Michael Levine, Trial Consultant/Expert Witness – Michael Levine Consulting

“I’ve been assisting on the preparation of expert reports for over 15 years and I have learned over time that it is important to include a methodology section toward the beginning of the expert report that clearly explains what your approach was to forming your opinions. This will be useful when it comes time for your deposition (sometimes months later) as a good reminder of what steps you took and why.

Lawyers for the opposing side will focus on an expert’s methodology as a basis to try to exclude that expert’s testimony under Daubert (some Frye states, too). Having a clear method that meets the Daubert criteria makes their job a lot tougher. Finally, make sure you write the methodology section so that the judge can understand it because the judge may review it when having to rule on a motion to exclude expert opinions / testimony.”

Wendy Pearson, President – Matson & Associates Environmental Consulting & Forensics

“Start off with a summary of your findings and conclusions. Follow that up with all the details and references which brought you to your conclusions. Remember that whoever is going to read your report is busy and probably doesn’t have the time to read through everything to get to the meat of your report. Like the old adage goes, tell them what you are going to tell them, then tell them what you told them.”

Brian Erickson – Aerospace Propulsion System Consultant

  1. “Lay a foundation that you are an expert in this field and that you have mastered all of the relevant the facts!
  2. Cite and have in possession, custody and control all documents containing relevant facts and data relied on and be prepared to cite to and produce those that were merely considered as well.
  3. Make sure you know what a reasonable degree of scientific certainty means in your particular case!
  4. Know the regulatory environment governing your field well enough to be an expert including statutes, regulations, codes, standards and guidance documents!
  5. And then – read it, know it, live it and consider follow up research for at least two weeks before your deposition or appearance.”

Arthur J. Clarke, Esq., Market Area Director – First Environment

“There are many experts well qualified in their field who know little or nothing about writing a good report. It is a whole different endeavor, a different skill set. It is not particularly hard, and it can be learned. But just believing you are an expert in one field does not make you proficient at writing. And if you have to write for legal cases, there are many other requirements that must be met, aside from just presenting your field of expertise. For those who haven’t done it, or haven’t studied the process, get some books, get some help. It makes a big difference in your practice and career.

Your report is your work product. As a consultant or expert, what we do is communicate. We have a special knowledge that others need, for whatever their purpose. If we do not communicate clearly, we have not done our job. And communication, as well as expertise, is what sets us apart as good consultants and experts.”

Russ Carlson, Owner – Tree Tech Consulting

“You should only submit a written report when requested to do so. With that being said, the report should present a short Executive Summary at the start of the report. The report should then contain: a short history of the matter, materials reviewed which are to the point with dates received, basis for your opinions [i.e. one or two sentences since your CV will suffice within this area, which will be attached], methodology [i.e. inspections, testing etc.], opinions stated succinctly and then a final summary. If disagreeing with another expert, this should always be done with complete respect. Every sentence should be scrutinized for how someone will interpret it later. Remember, you will be deposed on the contents and drilled later at trial.”

Thomas Bowler – Total Playground Consulting Services

“The most important asset for an expert is credibility. My reports are based on the forensic process; starting with the end result, then working backwards in time to connect the dots. Like Sergeant Friday used to say, “Just the facts, ma’am; nothing but the facts.”

Thomas A. Sharon, R.N., M.P.H. – Author and Expert in Nursing, Public Health and Patient Safety

“It is important for the report to show that the examiner has taken a balanced approach to the case. The methodology section should be clear so that another examiner could repeat the process to determine whether they come up with same results.

In the results section the report needs to show evidence that supports the opinion – and also refutes the opinion – then a discussion as to why one outweighs the other end to what degree. Too often expert reports only show evidence that supports the opinion leaving open the perception the examiner has taken biased approach whether that is true or not. This can impeach expert’s credibility on the witness stand.”

Michael Wakshull, Adjunct Instructor at University of Redlands, Founder – Q9 Consulting Inc.

“When I am asked to provide a written report, I begin my forensic report by listing the purpose for my examination. I list the items that I examined. I follow by stating my methodology-the equipment I utilized, followed by demonstrative illustrations, my conclusion and opinion. I keep the verbiage in the report simple and reader-friendly.”

E’lyn Bryan CFDE,BAI – Forensic Detective/Document & Handwriting Analyst

“When I prepare a life care plan or even an affidavit it is important that the information is not only “reader-friendly” but also understandable. If I put in medical abbreviations and terminology that no one can understand, I have not done a good job. I pride myself and my work in providing information not only to attorneys but to anyone that may be reading my final product.”

Margaret White, RN, LNC, NLCP, Legal Services Professional – Whitehouse Consultations/Life Care Planning

“Style of report varies enormously with the varying jurisdiction requirements and the varying needs of the attorneys. In some jurisdictions, draft reports are not discoverable. These can be written with emphasis on educating your attorneys. When reports are to be turned over, attorney education may be handled more with verbal contact, rather than relying on the report.

Some reports are very brief and vague, just enough to satisfy the minimal requirements of some jurisdictions. Others are filled out in excruciating detail to meet stricter requirements of other areas. Some are written with the intent of pushing a settlement. Some are written in the belief that the case will not settle before trial. Other reports may be affected by issues which a party may have in other cases which the expert is not even involved in. The truth is still the truth, but how it is presented may be greatly affected by the particular needs of the attorney for that particular case.”

Gene Litwin, Owner – Gene Litwin Safety Consulting

“I am a retired FAA Avionics Inspector. My field of expertise is aircraft systems. A common mistake I’ve experienced is beginning a report without establishing the basic fundamental proven laws of the systems in question. The laws of electricity, for example, are established beyond question, but the inclination to conclude that ‘everybody knows’ and not firmly establish these basic fundamentals such that all involved can understand is a trap that must be avoided. The subsequent case then can be built on these fundamentals without fear of being challenged.”

Monte Quist – Avionics Expert Witness

“Most attorneys who are not required to furnish an expert’s opinion would rather not, as they can definitely be a double-edged sword. Personally, when I am preparing an expert opinion I begin with my professional experience and recount the historical information concerning the case.I then detail my opinions on previous Expert Opinions by expert witnesses that are required in Federal Court and in various jurisdictions. I think about the deviations in the standard of care in a point by point fashion.

All of the attorneys that request I review cases for them receive a typed report from me even if I am not able to support their position concerning the allegations. I personally don’t feel I am doing the lawyer or his firm justice by simply providing a five minute phone call informing him that I will not be able to serve as their expert. Whereas a detailed letter permits me to clearly state my position on the case and my reasoning behind those positions affording him an opportunity to basically review an “expert report” from an “opposing expert”.”

Raymond P. Mooney, PA-C – Physician Assistant Expert Witness Services

“I’m not sure there are simple tips! Your report should be tight, based on evidence and clear to the reader. My general rule is to try and find at least two data points that support each of my opinions. We find that when the report is evidence-based, the opposing side often needs to scramble to refute!”

Julie Armstrong Psy. D. QME, Educator and Expert WitnessChild & Adult Psychological Issues and Nursing Standards

UK Experts

“Here in England, it would be frowned upon to start with your conclusions & follow with supporting evidence. The implication being that you made up your mind first & looked for supporting evidence to buttress your prejudice.

Start with an introduction describing the case, your instructions, the documents / evidence examined, and refer to an appendix containing a brief CV (= resume). Then set out in detail what you did, what you found, and what you infer (& why). Detailed schedules in support should be relegated to appendices. If appropriate, cover alternative inferences and explain why you preferred the view you have adopted. Then close with a summary of your conclusions & your expert’s declaration (of truth etc).

Remember only the lawyers & the judge will see the full report, most likely the jury will see none of it, so you will have to cover it in oral evidence from the witness box.”

David Winch, Expert Witness – Accounting Evidence Ltd.

“Explain specialist terms (I sometimes include a glossary) and reference any statements of fact that could otherwise turn into questions on the stand. If you say “72 percent of the time x occurs” and that is based on your own research, say so, if it’s based on other people’s research, say whose and include the reference. This will help the firm prepare. Where there are areas of contention in your field, explain your position with great care. Do not make the mistake of sounding arrogant, and do not use transparently persuasive language. Let your facts and evidence persuade. Attorneys are trained to see through rhetoric.

Watch out for writing using legal terms (unless you are a lawyer). Use the terminology of your own field with lay explanations. Let the attorneys do the law bit, that’s their job.

If I was asked to advise someone new to professional writing, I would suggest keeping George Orwell’s ‘rules’ for writers (see http://grammar.about.com/od/writersonwriting/a/OrwellRules.htm) and a copy of Strunk & White’s guide at hand.”

Dr. Mitzi Waltz – Associate Lecturer at Sheffield Hallam University

“Know the subject. Stay within your field of expertise and say what is outside (and who should address it).

Only put in required information, no waffle.Make the report individual to the case/ client – avoid pages of general information that are not directly relevant to that client. Be organised, the report should read chronologically. Follow the Civil Procedure Rules, even if it upsets instructors.

Never try to make a case (for either side). Never change opinion without documentary evidence, but be prepared to when new evidence comes to light. Everything is a draft initially.Produce reports in a timely manner. Give clear reasons for conclusions so that if one party disagrees they can see how the conclusions were reached. Be prepared to consider the range opinion – there are some pretty mad opinions out there. Always be courteous to the client, even when you know they are lying.”

Richard Scott-Watson, Expert WitnessOrthopaedic Trauma

“The more detailed part of your report can be useful to Counsel to base his/her questions on, but the summary is important too. It can depend on who you are writing your report for. If writing for a Jury trial, it’s even more important than usual to keep it very simple, easy to understand, free of all jargon and in everyday language – fit for the non-technical (even possibly uneducated) reader.

The one piece of guidance which experts absolutely must follow (in the UK) is either the Criminal Procedure Rules Part 33 (if in Criminal Court) or the Civil Procedures Rules Part 35 (if in Civil Court), published by the Ministry of Justice. The Criminal Rules have been rewritten with effect from October this year. The Criminal Procedure Rules (SI 2014 No. 1610 (L26)) are here: http://www.legislation.gov.uk/uksi/2014/1610/contents/made

Nick Jakob – Forensic Accountant in Public Sector

Canadian Experts

“I follow a few rules when writing my police pursuit reports, with reasonable success. They include:

  • Write for your audience.
  • Be clear. Just because you got a thesaurus for Christmas doesn’t mean you have to use long words.
  • Short sentences and short paragraphs.
  • Be concise – stick to the issue.
  • Make the layout and format attractive – lots of white space, using graphs, photos, maps etc. where appropriate.
  • Avoid the passive tense.
  • Read the report out loud to yourself. If it sounds clunky or doesn’t flow properly, then change it.
  • Consider using the IRAC ( Issue, Rule, Analysis, Conclusion) format to explain your rationale for reaching any given conclusion.

I recently authored a chapter on report writing in an investigation manual for the Asia Pacific Forum, which can be found here:


Gareth Jones, DirectorSpecial Ombudsman Response Team (SORT). Office of the Ombudsman of Ontario

“First, be comfortable with what you have opined upon. Know that you are giving an opinion for the benefit of the Court and not who retained you. The truth will always come out ( most of the time at least). Make sure that your opinion is based upon knowledge and education and experience of your profession that you are giving the report or testifying to. Otherwise, if the opinion is outside the expertise you have it will not be allowed in as it is hearsay.

Be consistent with the facts; then be consistent with the expertise as it matches the facts; and finally do not overstate your opinion – the conclusions should follow your analysis. To the best of your ability, try and stay away from the “lingo of your profession” as the Justice who is hearing your case will not understand and explaining every word on the stand is stressful even for experienced experts. There will be “stress” when testifying as that is what cross examination is all about from a lawyer’s perspective.”

Paul Mann, President – Paul Mann Professional Corporation

About the author

Joseph O'Neill

Joseph O'Neill

Joe has extensive experience in online journalism and technical writing across a range of legal topics, including personal injury, meidcal malpractice, mass torts, consumer litigation, commercial litigation, and more. Joe spent close to six years working at Expert Institute, finishing up his role here as Director of Marketing. He has considerable knowledge across an array of legal topics pertaining to expert witnesses. Currently, Joe servces as Owner and Demand Generation Consultant at LightSail Consulting.

background image

Subscribe to our newsletter

Join our newsletter to stay up to date on legal news, insights and product updates from Expert Institute.