Legal Issues in Occupational Ergonomics - Fundamentals and Assessment Tools for Occupational Ergonomics - page 43

to a jury (Davis, 2001). Limitations exist where testimony is based on scientific principles, formulas, dis-
coveries, or procedures developed by others (Rickgauer, 2001).
There is another form of testimony, based on inductive reasoning (from particulars to the whole)
(Holy Cross, 2001). This includes pure opinion based on the expert's own training, experiences, obser-
vations, and research (Ronnie Jones, 2003). For example, tire expert opinion may not be scientific
testimony (Kumho, 1999).
The logic involved may be a derivative of both hearsay and speculation objections. There is more credi-
bility when opinions are based on direct personal knowledge. There is less credibility when expert
opinions may involve some speculation in just applying someone else's results, beliefs, procedures,
and conclusions. A juror might not be able to distinguish between the weight that should be given to
direct knowledge as opposed to indirect knowledge, so the judge acts to balance the scales and assure
that only competent testimony reaches the jury.
3.4.7 Proffered Testimony
3.4.7.1 The Most Common Scenario
The vast majority of litigated cases involve expert testimony in which the expert witness's basic qualifica-
tions are quickly established and the expert testimony in court is generally unimpeded (with few objec-
tions and restrictions). In general, the testimony must be relevant (a tendency to prove or disprove, in
some way, the veracity of one or more of the basic issues contested by one or more of the parties). It
should be in a form acceptable to the court. Experts are generally held in high regard, depending on
the scope and depth of their qualifications, their publications, their occupational history, and any
honors they have received that have some connection with the issues of the case before the court.
They may be given special privileges such as utilization of otherwise hearsay or objectionable evidence
if that is the practice of their profession. They may be permitted to draw conclusions, whereas the lay
witness may be restricted to what they personally observed, heard, felt, or did.
3.4.7.2 The Defined Purposes of the Testimony
In complex or vigorously contested lawsuits, each segment of the expert's testimony may be related to a
defined objective. There may be pretrial or in-trial hearings, before the trial judge, to determine the
expert's qualifications and the admissibility of the proffered testimony. Such hearings may go far
beyond proof of general fault or its absence. It may focus on whether the proof relates to claims of a
product defect or an unsafe condition, inferences of knowledge or notice of a dangerous situation, the
causes of an accident, a failure to remedy or warn, evidence of mandated or secret recalls, records of
prior accidents that are substantially similar and not too remote, historical statistics on reasonable
human behavior under the circumstances, or the absence of prudent or due care. The judge may
admit evidence on one objective and deny it on other objectives.
For example, is there sound evidence, based on adequate foundation, concerning the specific (in this
case) tire failure? Does the proffered evidence relate directly to the tire defect (an unexpected steel belt-
from-belt peel or tire failure)? Does it relate to causation (wedge cracking and circumferential belt edge
failure due to the fatigue reversion of the skim stock holding the belts together)? Does it relate to pre-
dictable human driver reactions to unexpected tire failure? Was a recall, customer notification
program, or safety improvement program campaign necessary, timely, or sufficient? The trial judge
may go further on specific issues, to determine whether or not an opinion is justified or consists of
mere speculation. As a general rule, if the testimony is admissible, it is credibility that effects the
weight given to the testimony by the trier of fact.
3.4.7.3 Conflict in Governing Law
There may be a conflict as to which case precedents govern the admissibility of expert testimony. In
California, in 2004, there were two different appellate decisions (Roberti, 2003; Jennings, 2003). One
case stated that an expert witness “does not possess a carte blanche to express any opinion within the