Best Practices: Writing for Accessibility

May 3, 2008

Topics: Accessibility.

Thanks to an off-hand comment from Steve Green while discussing a forthcoming Accessites article, I’ve spent some time today thinking about what it takes to write for accessibility.

Most of the time, the primary focus of information about accessibility has to do with making non-text information available as text. Captioning and audio description for video, transcriptions for audio, simple text alternatives for static images. Next in the list tends to be availability of functionality: progressive enhancement for client-side scripting, ability to navigate the page via skip links or semantic HTML (HyperText Markup Language) headings, and so on.

But what about the content itself?

Disregarding issues concerning the use of abbreviations, typography, headings, and other semantic structures in HTML, the simple use of punctuation can be a significant barrier. This is a problem which applies to all text content for any user of a screen reader, in particular, although following these suggestions will benefit any reader of your content.

The issue isn’t precisely correctness. A sentence can be punctuated with perfect correctness but still lose clarity when spoken by a screen reader. It’s a matter of the lack of refinement in screen reader voice interpretation.

As a human speaker or writer, aware of the meaning and context of a sentence, it’s easy to speak a sentence and convey the meaning you expect in that sentence. A slight emphasis on one word or another is highly significant. However, in HTML, as in normal writing, there’s no means to indicate this kind of special emphasis which is readily understood by current screen reader technology. As important as strong and emphasis are semantically, they are not interpreted meaningfully by screen readers.

Punctuation is left as the sole means to refine and polish the meaning of a sentence for screen readers.

How do screen readers use punctuation?

Screen readers read most punctuation by default, such as parentheses, dashes, asterisks, and so on, but not all screen readers choose to read the same pieces of punctuation. Some do not read asterisks by default, for example. Periods, commas, and colons are usually not read out loud, but screen readers generally pause after each. Users can set their preferences so that screen readers read every punctuation mark and character. Web AIM, “Designing for Screen Reader Compatibility”

So common sentence punctuation marks, such as periods and commas, are indicated by pauses. However, special punctuation, including dashes and parentheses, are read as characters. This should immediately tell you how difficult it could be to understand a sentence containing numerous subclauses or parenthetical statements!

Only a few years ago, it was common to see pages that explained quote this page best viewed in Internet Explorer quote left paren or Netscape right paren. Web AIM, “Designing for Screen Reader Compatibility”, as rendered by Fangs

Although this is a relatively simple example, containing a single quoted passage and a single parenthetical statement, it could readily be very confusing to follow a more convoluted sentence structure, regardless of the correctness of the sentence.

So what’s the solution? Simply speaking, to write simply. Keep your sentences on the short side, avoid excessive parenthetical statements, and avoid excessive subclauses. Above all, try reading the sentence without giving any particular emphasis to the terms and see how easy it is to understand the statement. It’s easy to write an ambiguous sentence if you’ve assumed it will be pronounced in a particular manner.

Ultimately, the expectations when writing with a screen reader in mind aren’t that hugely different than without. After all, it’s not as if you intend to write confusing and ambiguous statements. However, the line drawn between “confusing” and “clear” is not necessarily in the same place for a computerized reader.

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14 Comments on “Best Practices: Writing for Accessibility”

  1. Perhaps you should also have mentioned the font size changing option. It can really enhance the way a reader perceives text on screen. Just as you see in news websites.

  2. I think that usability is most important thing, and you are right, even the punctuation is absolutely correct it still can confuse some readers. The usage of speech avatars is good decision of the problem. But I don’t like the sites which sounds is on when load. It’s very irritating.

  3. There are many ways to write a good statement in order to make it clear and understanding. Use more action words that make your writing more interesting.

  4. Yes, the top-down content authoring model can work when applied at every level of granularity: a general introduction to start off the document, a leading sentence which clearly defines the problem in each section of the document, etc.

    Organizing your document in such a manner that it’s crystal clear at any point what subject matter is being addressed is certainly important!

  5. Great article, Joe. I think this is an area most people ignore when it comes to accessibility: the actual content.

    When I worked at LexisNexis, we really endeavoured to introduce accessibility best practices through the entire design/development process, and thankfully the content was accounted for as well. One major change we had was the order of the most relevant bits of information. If you are listening to an entire list of elements, you want to hear the most salient information first, so you can skip to the next element if it’s not what you are looking for.

  6. Captcha is needed to remove all those pesky spams =/ I even had to remove comments altogether at one point due to the amount of spams I have.

  7. Using any CAPTCHA (Completely Automated Public Turing test to tell Computers and Humans Apart) is such a challenge — I definitely like your page of them! I really only resorted to this one out of desperation due to comment spam. It’s frustrating; but I finally just had to do it.

    Thanks for those articles. I’m looking forward to reading them (and then returning to this conversation, as well!)

  8. The analogy I used simply exhibited a change in behavior based upon the limitations of the medium. For example, I should write less complex because most screen readers have problems with complexity. Similarly IE (Internet Explorer) exhibits the most problems with standards, so I should use that as my browser. In both cases, if the user makes a decision not to dumb-down to the limitations, but rather use their own judgement, then they promote change for the greater good. That was my point. But granted, I probably could have made my point better by using a different analogy.

    As to the Alzheimer’s evidence — the original study was done by a nun and published in Time May 14, 2001.

    Here’s one article:,9171,999867-1,00.html

    And here’s some follow up.

    I am positive there are more. The article I originally read in 2001 was different than above. How’s that for memory?



    PS: I like your CAPTCHA (Completely Automated Public Turing test to tell Computers and Humans Apart) — here’s a few of my own:

  9. I don’t want to tell anybody how to write — but I do want to point out the consequences of that writing style.

    And please, do make a point of distinguishing between “complex sentences” and “overly complex sentences.” If you write well, than this may not be an issue — but there are a lot of people contributing web content who don’t!

    Telling me to change the way I write because of limitations in JAWS is like telling me to use IE (Internet Explorer) because more people use it. If we were all to do that, then M$ would not change their ways nor would we have better browsers like Safari and FireFox.

    I don’t think that’s a valid analogy — first, because I’m not describing limitations in JAWS: I’m describing limitations in screen readers. No screen reader fully effects pronunciation of sentence emphasis or punctuation. Second, because those aren’t correlative: the first part is changing a second party’s user agent, the second is changing your own.

    Besides, there’s evidence that suggest people who write shorter sentences have a higher chance of developing Alzheimer’s than people who write more complex sentences — interesting huh?

    Can you provide a citation for that? I’d be interested in reading about it!

    Thanks for your comments!

  10. I understand your point, but I write to express ideas.

    Telling me to change the way I write because of limitations in JAWS is like telling me to use IE (Internet Explorer) because more people use it. If we were all to do that, then M$ would not change their ways nor would we have better browsers like Safari and FireFox.

    If there is a problem with JAWS, then competition should change that.

    Besides, there’s evidence that suggest people who write shorter sentences have a higher chance of developing Alzheimer’s than people who write more complex sentences — interesting huh?

  11. I think that there are many ways of making a sentence more understandable — parentheses are one of them. And I don’t think there’s any problem with using them, even for screenreaders — it’s using frequent or nested parenthetical statements which I think is troubling.

    Usually, any long or complex sentence can easily be broken up into multiple sentences which may convey the same idea even better.

    It’s not a complaint about “using punctuation” — it’s about using punctuation instead of rephrasing a statement in more effective and simpler language.

    And I’m not even trying to address potential issues involving cognitive disabilities, which are certainly also relevant in this case.

  12. Seems to me Joe [Dolson] is just trying to making the user’s experience as positive as possible. Though this reminds me of something that happened a couple of days ago…. someone said I use too many parenthesis in my writing. If I do use them it’s because I feel they improve the understanding of the sentence. Not using them for screen reader users’ verbosity issues at the expense of clearer understanding seems a bit silly to me.

  13. Actually, I’m not recommending that people stop using punctuation — just that they stop using overly complex sentence structures. Frankly, this can make some people’s writing much easier to read for anybody.

    And I have absolutely no intention to stop appeasement of JAWS. This is because, very simply, I care about user experience, and I am going to take whatever steps I can to improve that. I have no significant influence on JAWS’ behavior. As much as I would love for screen readers to actually work correctly, it’s not the case today, and I see no reason to provide disabled users with an poor experience when I can avoid it.

  14. Well, here is the apotheosis of Too Much Accessibility: Stop using punctuation so it won’t bother people using devices that can’t even understand punctuation.

    It’s time for appeasement of Jaws to come to an end.