Eight Golden Rules: Rule 2 - Cater to Universal Usability
Continuing this series, the second of Shneiderman’s Golden Rules is that User Experience Designers should design systems and software for the widest range of reasonably possible users. This is a challenging, but not insurmountable, activity.
People come in a wide variety. For example, let’s consider physical vision for a moment, someone could have very strong eyes capable of seeing details at a distance or reading very small text on a monitor. Others, such as myself, struggle with details at a distance, and font sizes that were legible to me 20 years ago are no longer so. Still others might actually be physically blind, and require the aid of assistive technologies to make use of information displayed on a computer screen.
Further, people perceive color differently. Some can see a full range of colors, but there are a number of people who can only make out a reduced range of colors. Statistically, around 8% of men and 0.1% of women have a type of color deficiency within their vision. True “color blindness” does exist, but it is even rarer.
Finally, anyone can have vision issues under certain circumstances. For example, try distinguishing colors correctly under an amber streetlight or a red emergency light. A favorite example of mine comes from the 1988 movie “The Abyss”. Towards the end of the movie the main character is trying defuse a nuclear bomb with only a green hued light stick to see by, and the person talking him through it is referencing wires by color. As a side note, that’s one of the many reasons to use secondary encoding of information.
(The Abyss, 1989, 20th Century Fox)
This post talks largely about color and vision, we be could also consider aspects of hearing, fine motor control, education or technical experience. We also have to think about issues of cultural difference and languages, both written and verbal. And the list goes on!
This may seem daunting at first, but the key is what I said at the very beginning: we consider the widest range of reasonably possible users and base our design decisions from there. A very important phrase is the UX world is “Know thy user”. For example, if we are designing a system to control weather radar, we are likely to start with different user personas than if we were designing a voting kiosk or a mobile game. Learning who are users are, what makes them different physically, cognitively and culturally, is what lets us make the right design decisions.
References
Eight Golden Rules of Interface Design, Dr. Ben Shneiderman of the University of Maryland, website last accessed January 8, 2016, https://www.cs.umd.edu/users/ben/goldenrules.html
“Designing the User Interface” textbook, Shneiderman and Paisant, (fourth edition, Addison Wesley, 2005)