Applying the four principles of accessibility

Web Content Accessibility Guidelines—or WCAG—looks very daunting. It’s a lot to take in. It’s kind of overwhelming. It’s hard to know where to start.

I recommend taking a deep breath and focusing on the four principles of accessibility. Together they spell out the cutesy acronym POUR:

1. Perceivable
2. Operable
3. Understandable
4. Robust

A lot of work has gone into distilling WCAG down to these four guidelines. Here’s how I apply them in my work…

Perceivable

I interpret this as:

Content will be legible, regardless of how it is accessed.

For example:

• The contrast between background and foreground colours will meet the ratios defined in WCAG 2.
• Content will be grouped into semantically-sensible HTML regions such as navigation, main, footer, etc.

Operable

I interpret this as:

Core functionality will be available, regardless of how it is accessed.

For example:

• I will ensure that interactive controls such as links and form inputs will be navigable with a keyboard.
• Every form control will be labelled, ideally with a visible label.

Understandable

I interpret this as:

Content will make sense, regardless of how it is accessed.

For example:

• Images will have meaningful alternative text.
• I will make sensible use of heading levels.

This is where it starts to get quite collaboritive. Working at an agency, there will some parts of website creation and maintenance that will require ongoing accessibility knowledge even when our work is finished.

For example:

• Images uploaded through a content management system will need sensible alternative text.
• Articles uploaded through a content management system will need sensible heading levels.

Robust

I interpret this as:

Content and core functionality will still work, regardless of how it is accessed.

For example:

• Drop-down controls will use the HTML select element rather than a more fragile imitation.
• I will only use JavaScript to provide functionality that isn’t possible with HTML and CSS alone.

If you’re applying a mindset of progressive enhancement, this part comes for you. If you take a different approach, you’re going to have a bad time.

Taken together, these four guidelines will get you very far without having to dive too deeply into the rest of WCAG.

80 / 20 accessibility · marcus.io

So my observation is that 80% of the subject of accessibility consists of fairly simple basics that can probably be learnt in 20% of the time available. The remaining 20% are the difficult situations, edge cases, assistive technology support gaps and corners of specialised knowledge, but these are extrapolated to 100% of the subject, giving it a bad, anxiety-inducing and difficult reputation overall.

The Web Accessibility Cookbook

Manu’s book is available to pre-order now. I’ve had a sneak peek and I highly recommend it!

You’ll learn how to build common patterns written accessibly in HTML, CSS, and JavaScript. You’ll also start to understand how good and bad practices affect people, especially those with disabilities.

Home - Sa11y

Another handy accessibility testing tool that can be used as a bookmarklet.

Write Alt Text Like You’re Talking To A Friend – Cloud Four

This is good advice:

Write alternative text as if you’re describing the image to a friend.

The Folly of Chasing Demographics - YouTube

I just attended this talk from Heydon at axe-con and it was great! Of course it was highly amusing, but he also makes a profound and fundamental point about how we should be going about working on the web.