The_Secret_Benefit_Of_Accessibility_Part_2__A_Higher_Search_Engine_Ranking by georgetitan


The Secret Benefit Of Accessibility Part 2: A Higher Search Engine

Word Count:

How a website optimised for accessibility helps it achieve a high search
engine ranking.

usability, accessibility, web usability, web credibility, web
accessibility, css, website, accessible web design

Article Body:
An additional benefit of website accessibility is an improved performance
in search engines. The more accessible it is to search engines, the more
accurately they can predict what the site's about, and the higher your
site will appear in the rankings.

Not all of the accessibility guidelines will help with your search engine
rankings, but there are certainly numerous areas of overlap:

1. ALT descriptions assigned to images

Screen readers, used by many visually impaired web users to surf the web,
can't understand images. As such, to ensure accessibility an alternative
description needs to be assigned to every image and the screen reader
will read out this alternative, or ALT, description.

Like screen readers, search engines can't understand images either and
won't take any meaning from them. Many search engines can now index ALT
text though, so by assigning ALT text search engines will be able to
understand all your images.

2. Text displayed through HTML, not images

Text embedded in images appears pixelated, blurry and often impossible to
read for users utilising screen magnifiers. From an accessibility point
of view this should therefore be avoided.

Search engines equally can't read text embedded in images. Well, you can
just give the image some ALT text, right? Unfortunately, there's strong
evidence to suggest search engines assign less importance to ALT text
than they do to regular text. Why? Spammers. So many webmasters have been
stuffing their ALT tags full of keywords and not using them to describe
the image. Search engines have cottoned on to this form of spamming (as
they eventually do every form of spamming) and have taken appropriate

3. Descriptive link text
Visually impaired web users can scan web pages by tabbing from link to
link and listening to the content of the link text. As such, the link
text in an accessible website must always be descriptive of its

Search engines place a lot of importance on link text too. They assume
that link text will be descriptive of its destination and as such examine
link text for all links pointing to any page. If all the links pointing
to a page about widgets say ‘click here', search engines can't gain any
information about that page without visiting it. If on the other hand,
all the links say, ‘widgets' then search engines can easily guess what
that page is about.

One of the best examples of this in action is for the search term,
‘miserable failure'. So many people have linked to George Bush's bio
using this phrase as the link text, that now when miserable failure is
searched for in Google, George Bush's bio appears top of the search

4. Website functions with JavaScript disabled

JavaScript is unsupported by about 9% of web users (source: <a
either because they've turned it off (for example to prevent pop-up
adverts) or because their browser doesn't support it. Many forms of
JavaScript aren't accessible to web users utilising screen readers.

Search engines can't understand JavaScript either and will be unable to
index any JavaScript-driven content. Perhaps more importantly, they'll
also be unable to follow JavaScript-driven links. You may really like the
look of your dropdown menu but search engines won't if they can't access
certain pages on your site because there aren't any regular links
pointing at them.

5. Alternatives to Flash-based content provided

Flash, like JavaScript, isn't accessible to many users, including those
using screen readers. Equally, search engines can't access Flash so be
sure to provide equivalents.

6. Transcripts available for audio

Hearing impaired users obviously require written equivalents for audio
content to be able to access it. Search engines too can't access this
medium, but transcripts provide them with a large amount of text for them
to index.

7. Site map provided

Site maps can be a useful tool for visually impaired users as they
provide a straightforward list of links to the main pages on the site,
without any of the fluff in between.
Site maps are also great for search engines as search engines can
instantly index your entire site when they arrive at the site map it.
Next to each link you can also provide a short keyword-rich preview of
the page. All links should, of course, be made through regular HTML and
not through JavaScript (see 4. above).

8. Meaningful page title

When we arrive at web pages the first thing that appears, and the first
thing that visually impaired users hear, is the page title. This latter
group of web users don't have the privilege of being able to quickly scan
the page to see if it contains the information they're after, so it's
essential that the page title effectively describes the page content.

If you know anything about search engine optimisation you'll know that
the page title is the most important attribute on the page. If it
adequately describes the content of that page then search engines will be
able to more accurately guess what that page is about.

9. Headings and sub-headings used

Visually impaired web users can scan web pages by tabbing from heading to
heading, in addition to tabbing from link to link (see 3. above). As
such, it's important for accessibility to make sure that headings are
correctly marked up by using h1, h2 etc.

Search engines assume that the text contained in heading tags is more
important than the rest of the document text, as headings describe the
content immediately below them. Make sure you use the heading tags
properly and don't abuse them, as the more text you have contained in
heading tags, for example, the less importance search engines assign to

10. CSS used for layout

Screen readers can more effectively work through the HTML code of CSS-
based sites as there's a greater ratio of content to code. Websites using
CSS for layout can also be made accessible to in-car browsers, WebTV and
PDAs. Don't underestimate the importance of this - in 2008 alone there'll
be an estimated 58 million PDAs sold worldwide (source: <a

Search engines also prefer CSS-based sites and are likely to score them
higher in the search rankings because:

     The code is cleaner and therefore more accessible to search engines
     Important content can be placed at the top of the HTML document
     There is a greater density of content compared to coding

With all this overlap between web accessibility and search engine
optimisation there's no excuses for not implementing basic accessibility
on to your website. It'll give you a higher search engine ranking and
therefore more site visitors.

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