Evidence -- Expert Testimony: Admissibility of Human Factors Testimony Under the Federal Rules of Evidence

Testimony Under the Federal Rules of EvidenceIn recent years courts have liberalized the standards for admission of expert testimony.Federal Rules of Evidence 702 through 705 reflect this trend and are now in effect in many states as well as in the federal court system.I To be admissible under the rules, expert testimony need only assist the trier of fact. 2 Furthermore, a qualified expert is allowed to give opinions on ultimate issues, 3 which were previously reserved for determination by the trier of fact.Certain ultimate issues, including conclusions concerning whether a particular legal standard is satisfied, are still inappropriate for expert testimony, however, because simply telling the jury the result to reach does not constitute assistance.Moreover, when the mode of analysis applied by an expert lacks scientific reliability, there is a further danger that the expert's testimony will not assist but, instead, mislead.Human-factors analysis testimony demonstrates both of these dangers.According to a practitioner in the field, human-factors analysis is the "study of all the factors which combine to influence the decision of the individual, such as past experience, present feelings, and immediate motor response in terms of the present situation or environment."4 In a line of recent Florida cases involving railroad crossing accidents, 5 several psychologists and engineers have qualified as human factors experts and have been permitted to give their opinions on the probable behavior of the average or reasonable person in the actual accident settings.Assuming human-factors testimony satisfies the threshold test of assistance to the jury, the Florida courts nevertheless have failed to consider qualifications of the proferred experts adequately, neglected to determine whether human-factors analysis is scientifically reliable and overlooked the problem that expert testimony on the behavior of a reasonable person is not permitted even under the present ultimate issue rule.6 I.The Federal Rules of Evidence took effect in United States courts on July 1, 1975.Pub.L. No. 93-595, § 1, 88 Stat.1926 (1975).Twenty-one states have adopted these rules with omissions and variations.Fed.R. Evid.Serv.(state correlation tables) (1981).2. Fed.R. Evid.702. 3. Id. 704. 4. Public Health Foundation v. Cole, 352 So. 2d 877, 879 (Fla.4th Dist.Ct.App.1977), cert.denied, 361 So. 2d 834 (Fla.1978).The witness provided this explanation of human engineering, his subspecialty.Another human-factors specialist has defined his field as the study of how a human uses and interacts with his products.Fowler, Human Factors Analysis, 10 Trial, Nov.-Dec.1974, at 53. "Products" presumably refers to items such as consumer goods found in the home and more complicated devices like automobiles.5. See text accompanying notes 7-41 infra.6.The Florida legislature substantially adopted the Federal Rules of Evidence in 1976.Law of June 23, 1976, ch.76-237, 1976 Fla. Laws 556.The Florida Evidence Code appears in chapter 90 of the State statutes.Fla. Stit.Ann.(West 1979).The Florida evidence rules substantially follow the federal rules but contain numerous variations; omissions and additions.13