Junk Science

Expert Testimony

'Junk Science,' Court Decisions and Claims

Reprinted by permission from Claims Magazine, June - Source

By Charles C. Roberts Jr.

Court actions arising from insurance claims often involve technical matters in the fields of forensic science and engineering. Accident reconstruction, failure analysis and engineering analysis, among other technical areas of expertise, contribute to the development of evidence that significantly affects the course of a trial.

The current legal system allows technical experts to opine on scientific information that is above the knowledge level of the typical juror. The intent of the court is to use the scientific expert testimony to help the "trier of fact" understand and rule reasonably on complex technical cases. This has led to a plethora of "expert" witnesses offering opinions on virtually any subject; in some cases with virtually no basis and at virtually every hourly pay rate imaginable.

In his 1991 book, "Galileo's Revenge: Junk Science in the Courtroom," Peter Huber implies that some expert testimony has little basis in scientific fact and is plain junk, hence the birth of the popular term, "junk science." A recent television documentary by ABC focused on idiotic "scientific" testimony, an uncomplimentary exposé of obviously flawed science and the legal profession. The courts, appearing to be fed up with junk science, attempted to correct the condition of unscientific scientific testimony through a U.S. Supreme Court decision in the 1993 Daubert v. Merrill Dow Pharmaceuticals (509 U.S. 579, 1993) court action.

The Freye Test

Before discussing the consequences of the Daubert decision, a quick review of a previous ruling involving scientific evidence is helpful.

In the 1923 Freye v. United States case, the Supreme Court ruled that in order for scientific expert testimony to be admissible, it must have general acceptance in the particular field of study. The standard that the testimony be accepted in the "relevant scientific community" was broad and subject to abuse. Many decisions on the validity of scientific analyses were left to the jury to decide. The jury, often unqualified to assess scientific evidence, would make decisions based on the expert's personality, fancy courtroom displays and simplistic experiments that may have been irrelevant. This opened the floodgates to self-proclaimed experts and the proliferation of junk science. The legal profession does not escape blame, as they are the ones who hire such "scientists" so that a case will make it to the jury where emotion may trump relevant fact and evidence.

The Daubert decision

In Daubert v. Merrill Dow Pharmaceuticals, the high court concluded that trial judges should act as "gatekeepers" and not let in testimony based on junk science. When admitting expert testimony under the Federal Rules of Evidence, the U.S. Supreme Court identified the following four standards for the admissibility of scientific evidence:

Has the scientific theory or evidence been tested?

Has the scientific theory or evidence been published or subjected to peer review?

What is the error rate of the theory or technique and are there controlling standards?

Has the scientific community generally accepted the theory or technique?

The Supreme Court stressed that these four standards should be applied in a flexible manner and are non-exclusive. What has resulted from this ruling is a legal phenomenon known as a "Daubert hearing," in which one side tries to knock out the expert testimony of the other side by applying one or more of the four gatekeeper guidelines. It has been argued that under Daubert, technical testimony based on deductive reasoning such as that used by fire investigators and accident reconstructionists was nonscientific and excluded under Daubert. Arguments have ensued over whether technical knowledge is scientific or whether fields such as fire investigation are scientific.

The Kumho decision

In Kumho Tire Company v. Patrick Carmichael (526 U.S., 1999), the Daubert decision was revisited. A tire expert hired by Carmichael claimed a defect existed in a tire, manufactured by the Kumho Tire Co., that caused an automobile accident, resulting in the death of one of the passengers. The tire in question was more than five years old, had a tread depth of less than 2/32 of an inch in certain areas (which would not pass inspection in many states) and at least two punctures that had been inadequately repaired. There was also evidence of typical tire misuse, over-deflection and under-inflation.

Despite the apparent evidence that the tire was old and worn out, the tire expert formulated an opinion that a defect in the tire caused a blowout and the accident. The methodology used by the tire expert was unusual. He characterized four symptoms of over-deflection:

Shoulder tread wear (Figure 1- see original).

Bead groove pattern on the tire.

Sidewall deterioration (Figure 2- see original).

Marks on tire rim flange.

He indicated that if no more than two of four indicators of misuse existed in the subject tire, the failure had to be a result of a defect. Tire failure analysis usually involves determination of the failure origin and an analysis of cause of failure (see Insurance Adjuster, July 1986). A finding, by the process of elimination, that a defect exists without identifying the area of origin and the nature of the defect, is not always reliable.

Figure 3 (see original) is a view of a tire that showed no evidence of misuse but failed as a result of an impact with a pothole on an expressway. The tire was not misused, but was not defective either. Figures 4 (see original) and 5 (see original) show views of a spare wheel that had a 50 mph limit labeled on the rim but was operated at over 70 mph. It showed less than two of the four mentioned defects, but was obviously misused. Figure 6 (see original) is a view of a tire that failed from over-inflation, showing no sign of misuse, but was not defective either.

Kumho Tire moved to exclude Carlson's testimony based on one of the Daubert gatekeeper tests that the methodology was nonscientific and, therefore, unreliable. In this author's opinion, the court was correct in excluding this expert testimony, because of the momentous leap from general tire failure modes to a specific opinion on an existing defect.

The Daubert decision was interpreted narrowly that guidelines would be placed on scientists but not on experts in other fields. The Supreme Court decision in the Kumho case concluded that the trial judge is not only a scientific gatekeeper but also a gatekeeper of testimony based on "technical and other specialized knowledge." This broadened the scope of the Daubert decision to include not only scientists, but also engineers and other technologists. Like science, engineering relies on scientific knowledge and methodology, as do many other technical fields, such as agriculture, handwriting analysis and property evaluation.

The aftermath

The full meaning of the Daubert and Kumho decisions has not quite filtered down to judges and attorneys who are involved in technically related litigation. In Joechle v. Brown (Circuit Court of Cook County, IL 94 L 13346), the circuit judge asked an expert if a particular procedure, relied upon for an opinion, had been used in previous court cases. The expert indicated that he did not know of usage in other court cases. The judged used this response as a basis to exclude testimony based on Daubert.

In my opinion, the judge erred in that she focused on usage in previous court cases, which is scientifically irrelevant. What is relevant is the usage of the particular methodology in the scientific community. The particular calculations and procedure at issue had been used and accepted in the scientific community.

The Daubert decision makes non-scientists scientific gatekeepers. This may result in "good science" being excluded from the courtroom. A prime example is the understanding of the scientific field of biomechanics (see Insurance Adjuster, April 1985). Biomechanics is the study of the effects of forces and motion on the human body. Engineers perform biomechanical analyses to design automobile air bags, ski bindings, aircraft ejection seats and many other products. Many judges do not understand the difference between biomechanics and the field of medicine. They often mistakenly consider biomechanical analyses to be medical testimony and are known to bar such testimony when provided by engineers or other non-physicians who are skilled in that field.

Likewise, an electrical engineer may be barred from opining on a mechanical device even though mechanical and electrical engineers have virtually identical course work in the first two years of engineering school. There are many mechanical engineers who are skilled in failure analysis yet their testimony on failure modes analysis may be barred because they do not have a degree in metallurgy, even though courses on metallurgy are an integral part of mechanical engineering curricula. Some courts have resorted to hiring "independent" experts to evaluate the scientific testimony from each side. Their reports may act as a basis for a decision in a particular action.

In the future, the defense bar will most likely be helped by the broadened Daubert decision, in that there is a better opportunity to exclude testimony. The plaintiff bar will most likely be hurt, in that fewer cases will make it to a jury after surviving a Daubert challenge. More intense pre-trial Daubert-related court battles are expected, driving more claimants to more economical and less time-consuming methods of alternative dispute resolution.

Charles C. Roberts Jr., Ph.D., PE, is a consulting engineer based in Big Rock, Ill., and a contributing editor for Claims. He is primary author of the reference work, "Technical Notebook: Forensic Aspects of Claims," released by ClaimsBooks.

last updated 07/10/2008