Ethics and the Engineer as Expert Witness:

A Module for Classroom Exercises
Joseph H. Wujek, P.E. University of California at Berkeley

Department of Electrical Engineering and Computer Sciences

International Conference on Ethics in Engineering and Computer Science

Case Western Reserve University Cleveland, Ohio March 22,1999


design process; risk assessment; product quality, responsibility for; engineering ethics; corporate ethics; consumer/consumption information; ethics and the law


The training, perspective, and motives of the engineer and of the lawyer differ in many respects. In these classroom exercises we explore these differences as manifested in the engineer serving as an expert witness in US courts of law.

Some of the questions to be explored may be summarized thus.

What is an expert witness?

What are some of the differences between the lawyer's motives and the engineer's duty that may affect how the engineer acts, or is expected to act, as an expert witness?
Is the very function of the expert witness in conflict with the codes of ethics professed by the engineer? If so, in what specific instances? Is it possible to mitigate, even eliminate, these conflicts? If so, how?
We explore these and related questions by employing active learning in the "Think Pair Share" methodology of active learning. We then involve students in one or more exercises such as formal or informal debate, consensus-building, or impromptu theatrics. The latter may dramatize a plaintiff's lawyer preparing an expert witness (one or more students in turn) for testifying in a torts case. The rules of the theatrical exercise encourage coaching from the audience which usually results in involvement by most of the students. The author once played a plaintiff's attorney in a mock trial of a product liability case, a memorable and interesting experience.

These exercises, in addition to sensitizing students to ethical and legal issues, also raise awareness of the responsibilities of the engineer in product safety and related matters.


The assignments are intended for use in courses in statistics, circuit design, chip design, reliability engineering. Students should be in at least the third-year of an engineering, computer science, or bioengineering/biomedical curriculum; and have had some course work in circuits and systems.

The exercises may be part of a course in engineering professionalism, ethics, or societal implications of technology if students have suitable background as may be determined by review of the exercises.

For students lacking course work/experience in statistics and probability theory the results of the scenario calculations may be a "Given," accompanied by an appropriate explanation of the scientific and engineering implications of the numerical results. The solutions to the numerical problems may be found at:

Some understanding of Kant's Categorical Imperative, Utilitarianism, and the Principle of Informed Consent should enhance the pedagogic value of the drills. These are summarized below.

Two among several relevant Theories of Ethics
Another idea often relevant in engineering ethics is The Principle of Informed Consent. This means that the potential user(s) of our products and services must be made aware of hazards and other implications of using them.

The two scenarios given below may be used independently or used with the latter scenario conditioned by the former. The instructor may wish to revise the scenarios to suit better the educational background and interests of the class.


You (or another person, to be determined in class) work for Ajax Health Instruments, Inc. (AHI). Ajax is developing an implantable patient-monitoring device. The device is implemented on a single-chip: Chip X. The user ("patient") may download health-data by telephone to the hospital. Any mode of failure of this memory chip can be extremely hazardous to the patient because of incorrect data, data loss, etc.; and unknown or unidentified hazards. The majority of patients expected to have this implant will be over 50 years of age.

Field data for Chip X, under environmental stress conditions similar to Ajax's intended use, shows six failures in 1.77 million part-hours. From this, a colleague has computed the point-estimate of the failure rate:

Under the robust assumption of constant failure rate, the Mean Time To Failure (MTTF, or m), is the reciprocal of failure rate, so:
m = 2.95 (105) hours.
Upon seeing this result, the Chief Engineer exclaims, "Wow, thatís wonderful! The instrument operates continuously, so thatís 8,760 hours per year. So on average we can operate our unit without failures from the part for 34 years!"
Numerical Problems and Preliminary Exercises
What fraction of installed Chip X can be expected to fail after 1 year?
If failure of Chip X results in patient death one out of three times, what is the probability of death due to Chip X failure of one or more patients after 2 years? Assume that the entire patient population had the device installed at the same time, and that no other patient fatalities occur in the 2 year interval?
Compute the two-sided 60% confidence limits (lower 20%, upper 80%) of failure rate.
Repeat (c) for two-sided confidence limits of: 80%, 90%, and 95%.
On semi-log paper carefully plot the results of (c) and (d). Use failure rate as the variable of the log-axis.
Repeat part (a) but now using the upper 90% one-sided confidence limit of failure rate.
The Marketing Department of Ajax wants to run an ad in journals read by physicians. They intend to show prominently: "Reliability of 34 years!" Comment on this. Consider in your comments how the ethics code of one or more engineering societies may be invoked.
Is Chip X suitable for the intended application? What considerations should be evaluated, and how?
Discuss this scenario as it may relate to each of these concepts: informed consent, Utilitarian theory, and Respect-for-Persons.
If you had the responsibility for communicating to management the meaning of the failure-data stated in Scenario A, state what you would write in a summary memorandum.
Suppose that at the time of Scenario A you were not an employee of AHI and remained so until you were hired three months ago, at T = - 0.25 years. Your boss has assigned you the responsibility of sustaining engineering for the SavGuard product, the system described in Scenario A. Your duties include responsibility for vendor and customer liaison having to do with the SavGuard, and for following-up on engineering & manufacturing changes to the product.

From examination of the company archives and speaking to persons involved in the design and development of SavGuard, you have gained full knowledge of the events of Scenario A and events described in the following three paragraphs.

You feel comfortable with your job assignment and it is your belief that you know how to deal with the tasks implied by your responsibilities. Your self-confidence may change as a result of what follows.

Your boss and a person unknown to you visit you in your office, whereupon the stranger is introduced to you as a lawyer retained by the company for defending a pending lawsuit. Your boss asks you to "cooperate fully" with the lawyer, because "... it's all for the good of AHI and you." The lawyer hands you a file-folder having photocopies of newspaper clippings and several AHI in-house memoranda. You are also given a business card for the law firm. Your boss tells you to contact the lawyer as soon as you have read the file. You estimate that it will take "a day or two" to work through the file.

Your boss visits you and asks, "Have you finished reading the file?" You indicate having done so and your boss reminds you that you are to call the lawyer retained by the company. You ask your boss, "What's this about? I wasn't here for any of this...why was I asked to read the file and contact the lawyer?"

Your boss exclaims cheerfully, "Because we have you picked out to be an expert! We feel you have the stuffí to handle this, to represent the company in technical issues in a high-visibility activity! We have you set to be an expert witness in defending against this silly lawsuit."

Your boss explains, "We chose you because youíre articulate, self-assured, and sharp on tech matters,especially the SavGuard. And only you among our top engineers weren't at AHI back when that traitor left! That traitor to AHI is even going to testify against us in the suit! The plaintiff's lawyer cannot charge you as having prior knowledge in the case. You're PERFECT for the job! And do I need point out that your service to the company will be noted all the way to the top! This is a great opportunity for you to show your corporate loyalty and technical know-how."

You arrange a meeting with the lawyer. The lawyer outlines the trail strategy and your part in it.

"I want you to just answer my questions, no more and no less. We need to stress the idea that the company acted in good faith, and that the main component of SavGuard, Chip X, had a proven reliability of 34 years! So how could SavGuard fail after less than six months in the patient?! Impossible! We all KNOW that, it's just common sense. Stay away from technical stuff, the jury and judge won't understand it and they'll suspect you of trying to confuse matters. And whatever you do, no math! Who understands that mumbo-jumbo! The jury and judge will just distrust you ... after all, and please excuse me, nothing personal, but engineers are considered "gear heads" and "nerds," not normal people. In cross-examination the plaintiff's lawyer may try to get you to discuss the math. Don't let it happen. Just tell the court that the average life of the chip in SavGuard was proved to be 34 years. Stick with the averages! People understand that, there are baseball batting averages, bowling averages, stock averages from Wall Street, and all that. It's a world of averages, got it? I know youíll do a good job for the company, and youíll be paid a bonus for testifying as an expert witness."


Written Summaries

The exercises below are to be done by students working in pairs. Write down a few key ideas, then discuss them with your partner. Explain one another's ideas and arrive at a consensus if you can. The student-pair should prepare a brief written summary of your findings and be ready to discuss them orally.

Comment on the thoughts expressed in the following:
Summarize your understanding of the function of the engineer as an expert witness in a court of law.
Compare the relationship to Ajax Health Instruments, Inc. (AHI) of a lawyer employed or retained by AHI to the relationship to the engineer employed or retained by AHI as an expert witness. How do each relate to AHI customers? To the public at large?
Do you disagree with any aspect of the role of the expert witness? Explain.
Comment on the lawyer's statements and charges to you. What of the "proven reliability" comment by the lawyer? Distinguish between legal "proof", mathematical "proof" as in establishing a theorem, and acceptance/rejection of a hypothesis based upon statistically-valid tests. How would you respond to the lawyer? Be specific.
Comment on the lawyerís overall behavior as given in Scenario B files and dialogue.
Is there anything in an engineering society Code of Ethics that may be applicable in this scenario? If so, please explain thoroughly. (Consider any engineering society's Code of Ethics.)
General Discussion
Is there anything in the Code of Ethics examined in 7) above that you challenge as being inappropriate?
Is there anything in the Code of Ethics (as in 7 and 8, above) that is in conflict with your personal beliefs? Explain.
Consider the college or university you attend. In your opinion, is there an awareness and adherence to ethical principles within the College (or School) of Engineering students, staff, and faculty?
In your opinion, is there an awareness and adherence to ethical principles within the overall university or college you attend?
Consider the following and express your opinions why such a disparity exists, and what effects such may have upon the economy and quality of life in the USA.
The USA accounts for about 4% of the world's population, and in 1997 there were about 986 thousand persons practicing law in the USA. An estimate of worldwide figures may be had from the International Bar Association, "It is composed of over 18,000 individual lawyer members in 183 countries and 173 Law Societies and Bar Associations together representing more than 2.5 million lawyers."

Debate the question: Resolved, that the task of being an engineering expert witness is in conflict with the code of ethics of (name of an engineering society).
Act as mediator and find consensus among the three players in the theatrics given below. If theatrics are not performed, have three students meet, each taking a position as set out in the theatrics. The task is to find consensus and to then report areas of agreement and disagreement.
Use anything learned in the above exercises in carrying out what follows. Let the scene be set after the engineer has met with the lawyer. Present in the scene are the lawyer, the boss, and the engineer.

A student plays "the engineer" in the scenario, and in the dialogues outlined below. The other characters, the "boss" and the "lawyer," may be played by the instructor and a student, or by students only. If the instructor elects to participate, the role of boss is perhaps best-suited pedagogically, because the boss may alternately side with the engineer ("my people") and the lawyer ("my company's interests"). So doing will keep conflict in the scene.

Because conflict is necessary, but not sufficient(!) for a successful experience it is important that the other characters oppose the position voiced by the engineer. Therefore, if a student is chosen to play one of the foils to the engineer it is essential that the person disagrees with the position of the engineer. Such may be noted by polling the audience before choosing the player(s).

If the engineer agrees to do all or much of what the lawyer seeks, let the boss take exception to this as being "weak-willed," and lacking in character. To create or sharpen conflict the boss may berate the lawyer for "trying to make an automaton of my engineer!" The boss may be accuse the lawyer of "... being no more than a "hired gun, willing to do anything for a price!"

The rules of performance are flexible and should be based on the backgrounds of the students, level of experience in ethics instruction, etc. Some suggested options are:<

Encouraging the audience to coach the actors. The actors are free to accept or reject the advice from the audience. The more articulate or interesting suggestions from the audience may be used by selecting as a new actor the person who made the suggestion. The instructor may choose to "reset" the action to the initial scene or to continue the play from the moment the new actor entered the scene.
Stopping the play as needed to clarify a point, expand on the scenario, elaborate on something said in the theatrical dialogue, etc.
Switching roles. Each participant takes the positive of the arguments just argued in the negative. A good exercise in rhetoric!
Have a general discussion after the theatrics to summarize what was learned. Do a critique of how each player represented a personal agenda and compare to ethical behavior ideals. A written exercise done immediately after the performance may be useful.


A highly abbreviated listing of works on engineering ethics and societal responsibility of engineers and technologists. The World Wide Web is rich in ethics materials with many links. The Ethics Center for Engineering & Science at Case Western Reserve University is s good place to begin: <>.
Harris, C., Pritchard, M., and Rabins, M., Engineering Ethics: Concepts and Cases, Wadsworth, Belmont, CA, 1995
Johnson, D., Computer Ethics, Second Edition, Prentice Hall, Englewood Cliffs, NJ, 1994<
Johnson, D. (Ed.), Ethical Issues in Engineering, Prentice Hall, Englewood Cliffs, NJ, 1991
Johnson, D., and Nissenbaum, H. (Eds.), Computers, Ethics & Social Values, Prentice Hall, Upper Saddle River, NJ, 1995
Layton, E., The Revolt of the Engineers: Social Responsibility and the American Engineering Profession, The Johns Hopkins University Press, Baltimore, 1986
Martin, M. and Schinzinger, R., Ethics in Engineering, Third Edition, McGraw-Hill, NY, 1996
Susskind, C., Understanding Technology, San Francisco Press, San Francisco, 1985<
Unger, S., Controlling Technology: Ethics and the Responsible Engineer, Second Edition, Wiley, NY, 1994



Ethics and the Engineer as Expert Witness

by Joseph Wujek, P.E