It often emerges in “trip and fall” premises liability cases, that the plaintiff may not have seen a tripping hazard because of poor lighting or because of a latent defect in the construction or design of a walkway or entrance/exit. (Those are relatively “easy” cases.)  And in New York both the owner of the premises as well as the person lawfully on the premises have a duty to act reasonably under the circumstances.

If you are walking down the street, eyes glued to a smartphone screen, and you bump into a pole, concrete pedestal or perhaps even a hole on the sidewalk is it partially or even “totally” your fault? That is a question that the jury has to decide and it can be a big difference in the amount of damages you recover or if you can recover at all!

But what about cases where you are acting “reasonably,” using your senses to look where you are going, but you just didn’t see “what was there to be seen”: for example, a sudden “drop off” in elevation, and are injured because you fell.  You may feel that it was not really your fault at all because, for instance, you were browsing in a store and your attention was directed elsewhere (to the shelves filled with merchandise) and you did not expect the sudden “drop off”  in the middle of an aisle.

Most of us have seen zig-zag designs, brightly painted on the floor, to call your attention to such drop-offs.  The owner of the premises may have acted reasonably in warning you of the dangerous condition and that may be enough! But what if the facts are that in the very same area there was an overhead display, brightly lit, that drew your attention upwards?  And what about cases that involve so-called “optical illusions” or “optical confusion” because of the way the premises are designed, configured, painted, and so forth?

Is it enough for you to simply testify that you were confused or can you also use “expert testimony” to assist the jury in understanding exactly how and why people, like yourself,  are justifiably “confused” in such situations? And if can use expert testimony, do you use an architect, a psychologist, or some other expert to explain how and why people don’t perceive or overlook such dangerous situations? Such testimony is generally known as “human factors” testimony.

New York courts were originally hostile to the use of such testimony, but in the past decade or so have been much more open in admitting such testimony. Keegan, Keegan, and Strutt, L.L.P. have used “human factors” testimony for quite some time  in advancing the rights of injured clients.

Although as a concept, “human factors “is often associated with a sub-specialty of engineers who concentrate on design or highway safety cases etc.  psychologists also are used.  But you don’t have to have a special degree if you can show that what you have learned through you work  ( regarding “human factors” ) qualifies the expert to testify.

For example, an architect may become aware of what people perceive or don’t perceive regarding step drop-offs, or sunken living rooms: height, depth, spatial realities, optical illusions (and optical confusion) and so forth.

Here are a few case law examples from courts that have discussed and evaluated so-called  “human factors” testimony.

In Wichy v. City of New York, 304 A.D.2d 755 (2d Dep’t 2003), a New York City school teacher was allegedly injured when she tripped and fell in the school’s  gymnasium. The trial court refused to allow the testimony of a civil engineer with a master's degree in transportation engineering, to testify about  the human factors as they related to the alleged dangerous condition represented by the allegedly oversized riser at the base of the gymnasium doorway and granted the defendant judgment as a matter of law. The appellate court reversed the trial court’s ruling and reinstated the plaintiff’s complaint.

Hotaling v. City of New York, 55 A.D.3d 396, 398 (1st Dep’t 2008) aff'd, 12 N.Y.3d 862 (2009), the court held that while it was admissible for plaintiff’s expert to rely upon the Human Factors Design Handbook, by Woodson and Tillman, for the industry standards he applied— the expert had failed to establish whether the standard existed at the relevant time so as to be applicable to the facts at issue.

Further, a  Human Factors Psychologist might also  hold himself out as an  expert in Human Factors Psychology and Ergonomics, specializing in the area of safety of the interaction of people with products as they are used in the real world.

Human Factors Psychology (or “Human Factors”) has been described as “the study of human beings' relationship to, use of, and interaction with machines, other manmade devices and structures, and the environment in which they are encountered. Ergonomics refers to both the field of Human Factors and, more specifically, to the application and integration of Human Factors principles in product design and use.”

Moreover, the function of a Human Factors professional is to identify the hazards that may foreseeably arise in the use of a particular product and then identify the most appropriate means of eliminating or ameliorating the hazard.

See Campbell v. NACCO Materials Handling Group, Inc., 09CV376A, 2011 WL 5187930 (W.D.N.Y. Sept. 9, 2011) report and recommendation adopted as modified, Campbell v. Nacco Materials Handling Group, Inc., 09-CV-376A, 2011 WL 5240292 (W.D.N.Y. Nov. 4, 2011).

In Fedor v. Freightliner, Inc., E.D.Pa.2002, 193 F.Supp.2d 820.  (Fed. R. Evid. 702), a products liability action, it was alleged that the driver slipped on a step when exiting his cab due to faulty design. The court held that the “specialized knowledge prong”  was satisfied in finding plaintiff's proposed expert was qualified to testify, even though the proposed expert possessed a degree in experimental psychology rather than ergonomics/human factors; the expert had experience in the field of human factors via work  he had done in product design and safety, including design of steps and access/egress systems, and had written on various aspects of ergonomics and human factors.