Often I have been asked about the differences between accessibility and usability or which of them is more important. The truth is they tend to be used interchangeably and are equally important.
How I View the Terms Accessibility and Usability
My own view is accessibility will tend to refer to people having access to something. Where as usability is more about people being able to use something. As an example if a building has a flight of stairs leading to the door, people with mobility issues are going to have difficulty accessing the door. However, if the door was made of heavy stone and required great force to open it, many people will not be able to open it despite being able to access the door.
In the world of web accessibility, sometimes abbreviated to A11y, the term accessibility is broadly used for both access issues and usability issues. The term usability is generally used to define the ease of using any web interaction. Things like getting around a site or finding relevant information. In both cases it is about people interacting with your website through a wide range of web enabled devices.
WCAG2.0 and Accessibility
The WAI (Web Access Initiative), part of the W3C (World Wide Web Consortium), have produced WCAG2.0 (Web Consortium Access Guidelines). These are there to help web designers, web developers and web content authors produce accessible websites. However, it is not an easy read and without knowing a little about the people the guidelines are designed to help, it can be quite overwhelming.
So to help make those first steps, we will talk a little about people. After all, your website is potentially the most accessible communication media you have available to you.
Knowing your Audience
Firstly accessibility and usability effects everyone not just people who may have a physical impairment. If something is difficult or frustrating to use, most people will give up and look else where. If your website only works on one browser with specific add-ons installed at a particular screen resolution, it will limit the number of people who can use your site.
Secondly never assume, if your site is selling sports cars don’t assume that just because a visually impaired person can not drive one, that they are not going to buy one. People buy gifts, collectables and may appreciate all kind of things.
It is true many people with impairments can gain the most from accessible websites. It can be their life-line into equality and communication networks. A few examples may include elderly people who are not very mobile or live in remote locations or people who have a physical impairment such as hearing loss or visual impairment. It is worth remembering many people may have multiple impairments such as sight and hearing loss and these can be at varying degrees. There are other impairments that can effect many people like dyslexia or ADHD, these people are often effected by things like the use of colour or time sensitive tasks.
Understanding Disability Groups
I have broadly categorised disabilities into five groups below. Each category has a link to an article on Webaim, where you can read more about the disability and its effect with the web.
- Auditory : webaim.org/articles/auditory/auditorydisabilities
- Cognitive : webaim.org/articles/cognitive
- Motor : webaim.org/articles/motor
- Visual : webaim.org/articles/visual
- Seizures : webaim.org/articles/seizure
By understanding these broad groups of disabilities and the assistive technology people use to access the web, you can better appreciate the WCAG2.0 guidelines and why they exist.
Have your say
Tell us how you view the terms accessibility and usability, has it been a subject of controversy?