Website accessibility (for web geeks, current and aspiring)...
Category: Design...
Posted Wednesday, January 15, 2003 at 05:56 PM [GMT-6]

I'm giving a presentation in February at a lunchtime meeting sponsored by the Nonprofit Management Center of the Permian Basin. The talk will focus on websites for nonprofit organizations (my own design business excluded ;-), and will give some tips for using them to generate modest revenue streams, enough, at least, to pay hosting costs and domain registration. I'm also going to address some usability and accessibility issues.

While doing some research in the latter area, I learned something new: the placement of links on a webpage can significantly affect its accessibility by certain disabled visitors. Apparently, the assistive software/hardware used by those with mobility/dexterity or vision disabilities requires that the user move through a webpage in a linear fashion. Non-disabled visitors are able to move through the same page in a random fashion (and I'm sure I've always taken that for granted). The linear-movement constraint means that one must "tab" from one link to the next according to the order they appear on the page. This means that when a page has, say, 20 links in the right column - a very common layout - the disabled visitor must tab through 20 links before getting to the main text on the page.

The problem this poses a vision-impaired visitor should be obvious. The text-to-speech software can't read the main text until it is able to focus on it. The problem for the mobility-impaired visitor may be less obvious, but he or she can't access any imbedded links in that main text without going through the standard nav table.

Then, multiply this problem by the number of pages on the website, as every page is probably going to present the same standard navigational layout. What is otherwise considered effective design - standardized sitewide navigation - has actually become an impediment to accessibility.

So, what's the solution? According to the US Government's Access Board, the suggested solution is to provide a means of skipping repetitive navigation links. This is accomplished by placing in the upper left corner of a webpage a link that reads "Skip Navigation Links" or something similar, and point it to an "anchor" that resides "after" those nav links...say, at the beginning of the page's main text. Thus, the user of assistive technology could choose to either tab through the "Skip Navigation Links" link to access the nav links, or click on the Skip link to jump past them.

As I understand it, the Section 508 accessibility regulations actually require this "skip link" for repetitive nav bars, although I haven't noticed it on the few governmental sites I've recently visited. Here's why. Go to the IRS website. Pick out any page, and take a look at the source code. You'll find the following two lines near the top of the coding:

<a href="#skiplink"><img src="/irs/cda/common/images/blank.gif" alt="Skip To Main Content" width=1 height=1 border=0></a>
<a href="#leftNavSkip"><img src="/irs/cda/common/images/blank.gif" alt="Skip Past Header" width=1 height=1 border=0></a>

The IRS has chosen to place the Skip link around a 1x1 pixel transparent gif, counting on the screen reader to pick up the ALT tag to describe the function of the link.

Another solution, as suggested by accessibility expert and author Joe Clark, is to move the repetitive nav links to the right side of the page. This allows access of the main text without having to tab through the nav links (depending, of course, on how the page is actually laid out; there are ways of getting a right-side layout to appear in the code before the main text, which defeats the accessibility purpose). For more on Mr. Clark's candid opinions regarding accessible web design, read the transcript of his interview with Slashdot. He does have a observation about sites that use invisible GIFs for their Skip links, as we noticed on the IRS site (here's a hint: he doesn't like 'em. The invisible GIFs, that is, not the IRS.)

I thought I was pretty up-to-date on design issues affecting accessibility. I'm reminded once again that the opportunities to prove my relative ignorance are, um, relatively limitless. OTOH, a day in which I've learned something new is a day not wasted. I trust you take the same view.

[Note: I will certainly not get into this level of detail at the aforementioned luncheon meeting, but it is a good example of the complexities that we designers face on a daily basis. Now, don't you feel sorry for us?]