The Scientific Method Must Be Used by Expert Witnesses

The Supreme Court of the United States requirement that the scientific method must be used to qualify an expert witness’ testimony as reliable will have a far-reaching effect on the practice of law. In Daubert v. Merrell Dow Pharmaceuticals, Inc., 579 (1992), the U.S. Supreme Court took issue with what criteria should be used to determine the admissibility of scientific evidence. In the past, courts have relied on peer-reviewed evidence and evidence generally accepted by the scientific community. The court decided that Frye v. United States, 54 App. D.C. 46, 47, 293 F. 1013, 1014 (1923), no longer applied and instead that the Federal Rules of Evidence should be used. Judges were instructed to take a more “gate-keeping role” and to act more independently in assessing evidence, using relevance and reliability as their guide.

The Use of the Scientific Method Requirement Is Stated Exactly

In the Daubert decision, the U.S. Supreme Court ruled:

“But, in order to qualify as ‘scientific knowledge’ an inference or assertion must be derived by the scientific method. Proposed testimony must be supported by appropriate validation – i.e., ‘good grounds,’ based on what is known.” [emphasis added]

In Rosen v. Ciba Geigy Corp., 78 F.3d 316, 318 (7^th Cir. 1996), the Court said:

“Under the regime of Daubert . . . a district judge asked to admit scientific evidence must determine whether the evidence is genuinely scientific, as distinct from being unscientific speculation offered by a genuine scientist.”

Thus, in complex matters, opinions, theories, inferences, or assertions should be arrived at through use of the scientific method and not be just speculation or unsupported personal opinions.

Ensure “Expert” Witnesses Are Familiar with
the Steps or Stages of the Scientific Method

Federal Rule of Civil Procedure 25(a)(2) establishes a procedure under which each party must, before the date of the trial, make a detailed written disclosure with respect to each expert witness retained to testify. It would greatly help judges and the defining of issues if these disclosures were required to follow a guide for the scientific method such as SM-14.

No standard formula has been adopted for the scientific method. Those in the literature are usually condensed versions which vary considerably. Be sure your experts are familiar with a full formula, such as SM-14.

Here I show the SM-14 formula for the steps or stages of the scientific method and some questions that might be asked of expert witnesses to ensure that the “expert” is not just offering “unscientific speculation.”

Steps of the Scientific Method and Questions for Expert Witnesses

Expert Witnesses Should Be Asked About Applying the Scientific Method

Step or Stage 1 – Curious Observation. Have you been curious about all aspects of the problem? Any new ideas?

Step or Stage 2 – Is There a Problem? What is your definition of the problem involved? Does this agree with the issues in this matter so that your testimony will add to the jury’s knowledge? Previous to this matter, how much research have you conducted in the direct area of the problem now in questions? Where?

Step or Stage 3 – Goals and Planning. Note: By verbally asking questions or by reading a written report of the witness’ goals and planning and how he or she researched his or her testimony, you will get an idea of his or her professionalism and whether he or she followed the scientific method.

Step or Stage 4 – Search, Explore, and Gather the Evidence. Did you, for this matter, improve your knowledge of the subject about which you will testify? Where, when, and to what extent?

Step or Stage 5 – Generate Creative and Logical Alternative Solutions. Did you generate and consider alternative tentative hypotheses? Did you consider all contrary evidence? Note: The quality of the answer may indicate professionalism or bias.

Step or Stage 6 – Evaluation. Did you do any testing or experimenting? Can you show in chart form an evaluation of all tentative hypotheses you considered?

Step or Stage 7 – Make the Educated Guess (Hypothesis). Were you able to arrive at a working hypothesis? Does it fit the problem as you defined it? Did you make predictions based on it? Is it in a form that can be tested?

Step or Stage 8 – Challenge the Hypothesis. What further tests, experiments, or research did you do to test it? Did the predictions work out? Did you attempt to falsify it as well as support it?

Step or Stage 9 – Reach a Conclusion. Explain your final hypothesis or theory and its value to the jury in reaching a decision.

Step or Stage 10 – Suspend Judgment. How certain are you that your final hypothesis is correct? What may yet make it wrong?

Step or Stage 11 – Take Action. Have you ever subjected the theory you are supporting or one very similar to peer review? If so, what support or opposition resulted?

Supporting Ingredients of the Scientific Method

The following supporting ingredients are part of the SM-14 formula to aid in understanding and teaching the scientific method. The addition of these to the SM-14 formula makes it reflect the whole system of science and thus the complete method of creative problem solving and decision making. The proper use of these by expert witnesses would contribute substantially to good grounds and good science that the U.S. Supreme Court requires in the use of the scientific method.

Ingredient 12 – Creative, Non-Logical, Logical, and Technical Methods. Which main action methods have you applied in this matter in using the scientific method? Are these methods regularly used in your domain? Is there an error rate involved?

Ingredient 13 – Procedural Principles and Theories. Have you applied the procedural principles, ethics, and theories normally used to produce unbiased research?

Ingredient 14 – Attributes and Thinking Skills. Have you used the personal attributes normally used in impartial research? Have you been skeptical in your research and reasoning?