A List Apart

Menu

High Accessibility Is Effective Search Engine Optimization

Issue № 207

High Accessibility Is Effective Search Engine Optimization

by Published in HTML, Business, Accessibility · 71 Comments

Many web designers view search-engine optimization (SEO) as a “dirty trick,” and with good reason: search engine optimizers often pollute search engine results with spam, making it harder to find relevant information when searching. But in fact, there is more than one type of search-engine optimization. In common usage, “black-hat” SEO seeks to achieve high rankings in search engines by any means possible, whereas “white-hat” SEO seeks to code web pages in a way that is friendly to search engines.

Article Continues Below

In Using XHTML/CSS for an Effective SEO Campaign, Brandon Olejniczak explains that many web design best practices overlap with those of white-hat SEO. The reason is simple: such practices as separating style from content, minimizing obtrusive JavaScript, and streamlining code allow search engines to more easily spider, index, and rank web pages.

Two years later, I am going to take Brandon’s conclusions a step further. I have been a search engine optimizer for several years, but only recently have become infatuated with web accessibility. After reading for weeks and painstakingly editing my personal website to comply with most W3C Web Content Accessibility Guidelines, I have come to a startling revelation: high accessibility overlaps heavily with effective white hat SEO.

Accessibility for all users, even search engines

On further reflection, this overlap makes sense. The goal of accessibility is to make web content accessible to as many people as possible, including those who experience that content under technical, physical, or other constraints. It may be useful to think of search engines as users with substantial constraints: they can’t read text in images, can’t interpret JavaScript or applets, and can’t “view” many other kinds of multimedia content. These are the types of problems that accessibility is supposed to solve in the first place.

Walking through a few checkpoints

Now that I’ve discussed the theory of why high accessibility overlaps with effective SEO, I will show how it does so. To do this, I am going to touch upon each Priority 1 checkpoint in the W3C Web Content Accessibility Guidelines which affects search-engine optimization.

1.1 Provide a text equivalent for every non-text element (e.g., via “alt”, “longdesc”, or in element content)...

Not only are search engines unable to understand image and movie files, they also cannot interpret any textual content that is based on vision (such as ASCII art). alt and longdesc attributes will, therefore, help them understand the subject of any such content.

Search engines are also “deaf” in reference to audio files. Again, providing textual descriptions to these files allows search engines to better interpret and rank the content that they cannot “hear.”

1.2 Provide redundant text links for each active region of a server-side image map.

Text links are very important to search engines, since anchor text often succinctly labels the content of a link’s target page. In fact, many search engine optimizers consider anchor text to be the single most important factor in modern search algorithms. If a website uses an image map rather than a text-based menu as the primary navigational method, a redundant text-only menu elsewhere on the page will give search engines additional information about the content of each target page.

4.1 Clearly identify changes in the natural language of a document’s text and any text equivalents (e.g., captions).

Major search engines maintain country and language-specific indexes. Specifying the language of a document (or of text within a document) helps search engines decide in which index(es) to place it.

6.3 Ensure that pages are usable when scripts, applets, or other programmatic objects are turned off or not supported [...]

Some users choose to disable JavaScript and applets in their browser’s preferences, while other users’ browsers do not support these technologies at all. Likewise, search engines’ “browsers” do not read scripts; therefore a webpage’s usability should not be crippled when scripts are not supported. Otherwise, search engines may not even index the page, let alone rank it well.

14.1 Use the clearest and simplest language appropriate for a site’s content.

It is a bit less obvious how this particular checkpoint aids SEO. But if a website contains the “clearest and simplest language appropriate for the site’s content,” it is probably using those keywords with which potential searchers will be most familiar. Searchers tend to use succinct queries containing familiar language. Thus, to receive maximum traffic from search engines, it is best that a website contain the same words which the site’s audience will use when searching.

The benefits do not end with Priority 1—many of the Priority 2 and 3 Checkpoints are important for SEO purposes, too. For instance, Checkpoints 6.2 and 6.5 refer to the accessibility of dynamic content. In fact, making dynamic content search engine-friendly is one of the most daunting tasks a search engine optimizer faces when working on an ecommerce or database-driven site. Following the W3C’s recommendations can help to avoid any indexing or ranking problems related to using dynamic content.

From the horse’s mouth

If you doubt any of the above, perhaps a visit to Google’s Webmaster Guidelines could convince you that Google rewards high accessibility. This page specifically mentions best practices which will help Google “find, index, and rank your site.”

Design and Content Guidelines:

  • Make a site with a clear hierarchy and text links. Every page should be reachable from at least one static text link.
  • Offer a site map to your users with links that point to the important parts of your site. If the site map is larger than 100 or so links, you may want to break the site map into separate pages.
  • Create a useful, information-rich site, and write pages that clearly and accurately describe your content.
  • Think about the words users would type to find your pages, and make sure that your site actually includes those words within it.
  • Try to use text instead of images to display important names, content, or links. The Google crawler doesn’t recognize text contained in images.
  • Make sure that your title and alt tags are descriptive and accurate. [...]

Technical Guidelines:

  • Use a text browser such as Lynx to examine your site, because most search engine spiders see your site much as Lynx would. If fancy features such as JavaScript, cookies, session IDs, frames, DHTML, or Flash keep you from seeing all of your site in a text browser, then search engine spiders may have trouble crawling your site.

Note that each of Google’s guidelines actually correlates with a W3C Web Content Accessibility Guideline. (Oddly enough, the word “accessibility” does not actually appear in Google’s Webmaster Guidelines. Perhaps they are afraid of scaring off some webmasters with technical jargon? In any case, it is clear that Google is lobbying for high accessibility.)

SEO: just another feather in accessibility’s cap

The checkpoints I highlighted above are just a few of the many ways that high accessibility will help optimize a website for search engines—many of the other checkpoints in the W3C Web Content Accessibility Guidelines are helpful to SEO, as well. Of course, to most web designers, the goal of accessibility is (and should be) to make sites accessible to all people, independent of their platform or any disabilities they have. But if accessibility gets a website more traffic from Google, even better!

The good news is that a web designer who follows best practices for accessibility is already practicing solid white hat SEO. Search engines need not scare anyone. When in doubt, design your site to be accessible to blind and deaf users as well as those who view websites via text-only browsers, and SEO will fall into place.

71 Reader Comments

Load Comments