Human Factors and Usability: A Fine Line

At a glance, the terms "usability" and "human factors" appear similar. Their consequences are definitely alike; both can cause ease or frustration for a person depending on their quality. For example, if computer users have good usability and human factors, then they are comfortable and efficient.

However, while usability refers to the usage quality of software and websites, human factors relate to the functional quality of hardware. In the past, human factors were synonymous with ergonomics, or workplace design. A more recent definition of human factors is "the integrated research on human performance, technology design, and human-technology interaction."

Human performance involves memory span, eye movement, fatigue level, and motor skills. Researchers can measure human performance by observing, monitoring, and testing subjects when they use technology. Technology design, the second component of human factors, can include graphical use interfaces (GUI) for computers, the shape of a monitor, or the size of a keyboard. Finally, human-technology interaction combines the other two components so tasks can be accomplished.

To help perform tasks easily and efficiently, technology must meet the capabilities and skills of human users, not vice versa. In other words, technology must be customized according to users´ needs. Customization is, therefore, the core purpose behind human factors.

Regarding people with disabilities, determining specific human factors is vital for their independence and productivity. For instance, some individuals who use head pointers and mouth sticks to type must have keyboards tilted to improve performance. If they use the keypad for mouse functions, the keyboard may have to be moved a little to the left so the numeric pad can be easily reachable. In addition to keyboard position, mobility impaired individuals-- as well as all other computer users-- must also have comfortable seating to prevent tremendous strain and thus reduce fatigue.

For those with visual impairments, customizing their computer systems may imply larger monitors to view content more easily and attached speakers to hear screen readers more clearly. Velcro may also be placed underneath input devices, such as the mouse or joystick, so visually impaired users can locate them quickly.

The advantages of optimizing human factors and usability for persons with disabilities are clear. If hardware and software prove to be functional and adaptable according to their skills and needs, then individuals with disabilities become more independent, productive members of society.

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