Human Factors, contrary to certain descriptions, is anything but a "soft" science. In certain topical areas, such as the measurement of body dimensions, experimental design, and perception, there are tabulated bases of hard data, as well as rigorously constructed mathematical formulae that describe the capabilities and limitations of humans.
Often, legal theories are built upon what a person could be expected to see, hear, feel, or otherwise detect and perceive. In the area of perception, human factors practitioners are well equipped to aid attorneys and the court in understanding the thresholds of human perception and the magnitude of differences required for people to reliably detect changes in their environment.
The two senses most often at issue in legal cases are vision and hearing. Questions related to what a person might have been expected to see and hear are common. Beyond simple detection thresholds, most cases involve higher levels of perceptual capability, such as the ability to read a warning or road sign, hear a persons voice or a siren, etc.
