As I write this, Google Labs is developing their Web Accessible Search Engine which gives a higher priority in search results to pages which meet the W3C WAI Web Content Accessibility Guidelines (WCAG).
Similarly, Net-Guide - a UK-based search engine - excludes non-compliant web sites in favor (or maybe that should be favour) of Web Accessible ones.
Rollyo's Teaching In My PJs Search Engine specifically targets web accessible sites. This short list of Web Accessible-Friendly Search Engines will no doubt be expanding in the future.
Why? In theory, a website owner that fails to provide accessible information and functionality for all users could be sued for discriminating against disabled people. Could your company survive a costly discrimination law suit?
If all that isn't sufficient reason for building web accessible sites then you're missing the upside. One of the main benefits of Web Accessibility is that a Website that's more accessible to people - all people - is also usually more accessible to search engines. That's right. And the more accessible your site is to search engines, the easier it is to identify your content for what it is. Better content identification provides a better chance at a top spot in search engine rankings.
To be honest, not all of the WCAGs will necessarily help you improve your search engine rankings. But there are many overlapping areas that could. So let's examine the important ones.1. Descriptive Page Title
When we arrive at Web pages, the first thing that appears -- the first thing that visually impaired users hear -- is the page title. Visually impaired 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 describes the page content in a meaningful way. "Home Page" or "Index" doesn't say much about the content contained on your opening page. Whereas "Your Company Name - Start Page" says more.
If you know anything about search engine optimization you'll know that the page title is among the most important attributes on the page. If it adequately describes the content of that page, more search engines will be able to accurately interpret what that page is about.
2. Use Headings and Sub-Headings
Visually impaired web users can scan web pages by tabbing from heading to heading, as well as from link to link (see point 3 below). As such, it's important from an accessibility standpoint to make sure your headings are correctly marked up using <h1>, <h2>, etc. tags.
As a general rule, most search engines will assume that the text contained in heading tags is more important than the rest of the document's text, as headings describe the content immediately below them. Search engines assign the greatest importance to <h1>, then <h2>, and so on. Make sure you use the heading tags properly. Don't abuse them -- the more text you have contained between heading tags, for example, the less importance search engines may assign them.
3. Use Descriptive Link Text
Visually impaired Web users can scan Web pages by tabbing from link to link, listening to the content of the link text as they go. As such, the link text in an accessible Website must always be descriptive of its destination.
Search engines are generally seen to place importance on link text, too. Many engines assume that link text will be descriptive of its destination, so they examine the text of all the links that point to a given page. For instance, if all the links pointing to a page about widgets read, '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 the linked page is about.
One of the best examples of this technique 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 the words "miserable failure" are searched on Google, George Bush's bio appears on top of the search rankings!
4. Assign ALT Descriptions to Images
Screen readers, which are used by many visually impaired Web users, can't understand images. To ensure accessibility, an alternative description needs to be assigned to every image; the screen reader will read out this alternative, or ALT="image description goes here."
Like screen readers, search engines are commonly assumed to be unable to understand images. But some search engines index ALT text. By assigning ALT text to your images, those engines will be able to understand even your pictorial content.
Of course, numerous search engines don't take any notice of ALT text. The proliferation of ALT tag spamming undermined the relevance of ALT text in the eyes of these engines, which no longer consider it in their relevance algorithms.
So, why bother with image ALT text? Because your rankings may improve in search engines that do take it into account, and make your site more accessible.
5. Display Text Through HTML or XHTML, Not Images
Text embedded in images appears pixelated, blurry, and is often unreadable by those who use screen magnifiers. From an accessibility point of view, text embedded in images should therefore be avoided.
It seems that at present, search engines are also unable to read text embedded in images. Well, you can just apply ALT text to those images, right? Unfortunately, there's strong evidence to suggest that search engines assign less importance to ALT text than they do to regular text. Why? Spammers (again!), as explained above.
The answer? To ensure that your site is accessible and your content counts as much as possible toward your search ranking, avoid embedding text in images.
6. Disabled Website Functions
JavaScript is unsupported by about 4% of Web users, either because they've turned it off for security reasons (perhaps to prevent pop-up ads) or because their browser may not support it. Many forms of JavaScript - Dynamic link menus, AJAX, Sprys, etc... may not be accessible to those who use screen readers.
It's accepted that few, if any, search engines can understand JavaScript - see Getting Into Google - Google Speaks. These services will likely 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 dynamic or Flash-driven drop-down menus, but search engines won't if they can't access pages on your site via regular text links.
7. Provide Alternative Text for Flash and Java based Content
Flash and Java aren't accessible to many users either, including those using screen readers. Likewise, few search engines can access Flash or Java so be sure to provide HTML or XHTML equivalents.
8. Transcripts Available for Audio
Hearing impaired users obviously require written equivalents for audio content in order to access that information. Typically, search engines are also unable to access audio content whereas 'transcripts' provide relevant text that can be indexed by Search Engines.
9. Provide a Site Map
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.
Site maps are also great for search engines because most search engines can instantly index your entire site once they arrive at the site map. Next to each link you might also provide a short keyword-rich preview of the page, to improve both the user experience and potential search ranking. This is particularly important for dynamically driven web sites whose content is contained in a database. All links should, of course, be made through regular HTML or XHTML expression and not JavaScript, AJAX, Flash or Java (see points 6 & 7 above).10. CSS Used for Layout
Screen readers can more effectively work through the XHTML or HTML code of CSS-based sites as there's a greater ratio of content to code. Websites using CSS-based layouts can also be made accessible for specific devices such as computer printers, handhelds (Mobile Phones, Blackberries), braille printers, aural readers, TV and others.
Search engines tend to rate CSS-based sites higher in 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
Several web site designers have told me that when they changed their site from regular table-based layouts to a CSS-based layout, traffic stats to their sites increased significantly.
Summary
With the overlap between improved Web Accessibility and Search Engine Optimization (SEO) there's no reason NOT to incorporate basic web accessibility methods into your websites. It's a bit like the Mother Goose rhyme, The House That Jack Built... Build a Web Accessible site to improve your site's perception and visibility by search engines. Greater visibility by search engines might lead to higher search rankings. Higher search rankings could lead to more site visitors. More site visitors means more potential customers. And so on...References:
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1 comments:
Thank you for this information. I think that better web accessibility will definitely lead to better search ranks. If more people find your web page easy to use then it can only be a good thing.
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