Human Factors Expert Witness

What Can a Human Factors Expert Help Determine?

In litigation, a human factors expert evaluates how people perceive information, recognize hazards, make decisions, and interact with equipment, environments, warnings, procedures, and other people. Rather than simply asking whether someone made an error, human factors analysis examines why the action occurred, what information was available at the time, and whether the surrounding system accounted for foreseeable human behavior and limitations.

Depending on the facts of the case and the expert’s qualifications, human factors analysis may help address questions such as:

Could the Person Reasonably Perceive the Hazard?

An expert may evaluate whether a hazard, object, condition, warning, vehicle, or person was reasonably detectable under the circumstances. Relevant factors may include visibility, lighting, contrast, obstructions, viewing angle, distance, movement, conspicuity, and the individual’s expected focus of attention.

Was the Person’s Attention Directed Elsewhere?

People have limited attentional capacity. Human factors analysis can examine whether competing tasks, environmental conditions, equipment operation, communications, workload, or other demands reasonably affected what a person noticed or failed to notice before an incident.

Was a Warning or Instruction Likely to Be Seen, Understood, and Followed?

The presence of a warning does not necessarily establish that it effectively communicated the hazard. A human factors expert may evaluate the warning’s placement, visibility, wording, signal words, symbols, timing, context, and whether the information provided the user with a meaningful opportunity to understand and respond to the hazard.

Was the Hazard Sufficiently Visible or Conspicuous?

Visibility involves more than whether something was physically present within a person’s field of view. An expert may evaluate whether a hazard was sufficiently noticeable against its surroundings considering lighting, contrast, color, size, motion, visual clutter, obstructions, and the observer’s expected line of sight.

Did the Person Have Sufficient Time and Information to Respond?

Human factors analysis may consider when relevant information first became available, when the hazard could reasonably have been detected, what decisions were required, and whether sufficient time existed for a person to perceive the situation, understand its significance, select a response, and act.

Was the Person’s Behavior Foreseeable?

Human behavior does not always conform perfectly to written procedures or idealized expectations. An expert may evaluate whether the actions taken were reasonably foreseeable given the task, environment, equipment, training, experience, workload, incentives, established work practices, and information available at the time.

Did the Task or Equipment Increase the Likelihood of Human Error?

Human error may be influenced by the way a task, workplace, machine, control, display, or procedure is designed. A human factors expert may evaluate whether the system created unnecessary opportunities for confusion, omission, misinterpretation, incorrect control selection, loss of situational awareness, or other predictable errors.

Were Controls, Displays, or Interfaces Designed for Effective Human Use?

In equipment-related cases, human factors analysis may address the location, labeling, organization, visibility, consistency, and usability of controls and displays. The expert may consider whether the interface provided users with clear information about equipment status and supported appropriate operation under foreseeable conditions.

Did Training and Procedures Account for How the Work Was Actually Performed?

Written procedures and training programs can be evaluated against real-world operating conditions. A human factors expert may consider whether instructions were understandable, whether critical information was emphasized, whether workers were expected to remember excessive information, and whether the prescribed procedure was practical under actual working conditions.

Did Workload, Fatigue, Stress, or Competing Demands Affect Performance?

Human performance can be influenced by physical and mental workload, fatigue, time pressure, interruptions, repetitive tasks, environmental stressors, and simultaneous responsibilities. Where supported by the evidence, these factors may help explain changes in attention, decision-making, reaction, or task performance.

Was the Environment Designed Around Foreseeable Human Capabilities and Limitations?

Human factors considers whether workplaces, equipment, tasks, and systems accommodate the people expected to use them. This may include evaluating reach, posture, strength, movement, visibility, information processing, memory demands, and other physical or cognitive capabilities.

Was the Incident Simply “Human Error,” or Did the System Contribute?

Describing an incident as operator error, worker error, or user error may identify the final action in a sequence without explaining why that action occurred. Human factors analysis can examine whether equipment design, task demands, procedures, warnings, environmental conditions, training, supervision, or other system characteristics contributed to the behavior that preceded the incident.

How Would a Reasonable Person Be Expected to Interact With the Same Conditions?

Where appropriate, an expert may compare the actions involved in an incident with established human factors principles, scientific research, expected human performance, and foreseeable patterns of behavior. This can help distinguish between conduct that was unusual and conduct that a reasonably designed system should have anticipated.

Ultimately, a human factors expert helps counsel move beyond the question of what a person did and evaluate what the person could reasonably perceive, understand, anticipate, decide, and do under the circumstances. That analysis can be particularly important in cases involving workplace accidents, industrial equipment, construction activities, warnings and instructions, premises conditions, machinery, vehicles, and other situations where human behavior interacts with the design of a task, system, or environment.