508 at a Glance
This guide serves as the bare minimum to meet the Section 508 standards for accessible web sites. Meeting these standards does not ensure a completely accessible web site, but one that is satisfactory for disabled users. You should always do an accessibility check with assistive technology software to make sure your web site is navigable for your audience. Every guideline must be followed to meet with government standards. Techniques about meeting each guideline are discussed in further detail. Since the campus supports Dreamweaver, links to Dreamweaver tutorials (where applicable) are available if you do not feel comfortable with editing HTML code. Web sites further explaining accessibility are www.w3c.org and www.section508.gov.
Alternate Text - Checkpoint (a)
"A text equivalent for every non-text element shall be provided (e.g., via "alt", "longdesc", or in element content)."
Screen readers cannot interpret non-text elements, which are most often images, so you must provide text alternatives by using the alt attribute. In Windows, if you use Internet Explorer, can you do a quick check for alternate text by positioning your mouse over your images as shown in the more information for Alternate Text. The alternate text will pop up, if available. Mac users can use different browsers, like Netscape. Multimedia elements should have text alternatives synchronized with its content, as specified in the More Information part on Captioning.
Captioning - Checkpoint (b)
"Equivalent alternatives for any multimedia presentation shall be synchronized with the presentation."
Captioning allows deaf people to comprehend multimedia with text. You must synchronize captions for things such as video, audio, or animations. Click here for more information on captioning programs.
Color - Checkpoint (c)
"Web pages shall be designed so that all information conveyed with color is also available without color, for example from context or mark-up."
Section 508 guidelines do not discourage color, just the use of color to convey information. The image shown below is a bad example of the use of color.
CSS Style Sheets - Checkpoint (d)
"Documents shall be organized so they are readable without requiring an associated style sheet."
Section 508 guidelines implicitly support the use of CSS style sheets, so you should use them to help make your web site accessible. You are required, however, to make your web site usable if the style sheet is turned off. This is because some disabled users use their own style sheets to make text larger or to make the web site display high contrast colors. Section 508 also recommends using CSS's absolute positioning instead of tables, but using tables for layout is fine as long as your content makes sense when a screen reader reads it. A web site that uses tables for layout can still be 100% accessible.
Server-Side Image Maps - Checkpoint (e)
"Redundant text links shall be provided for each active region of a server-side image map."
You should rarely encounter server-side image maps since most image maps are now client-side image maps. When you click on a hot area of a server-side image map, the server decides where to take you. This poses problems for screen readers, since screen readers do not know where the link goes, which means your users won't know as well. Section 508 guidelines recommend you use client-side image maps wherever possible. If you must use server-side image maps, include redundant links for each active region and locate the links next to or below the image map. The alt text is used to alert the user that alternate links are available for the server-side image maps.
Client-Side Image Maps - Checkpoint (f)
"Client-side image maps shall be provided instead of server-side image maps except where the regions cannot be defined with an available geometric shape. Client-side rather than server-side image maps should be used unless there are limitations in creating hot spots in client-side image maps tools/software."
Client-side image maps have clickable hot spots that act as links. Clicking on a different area of the image takes you to a different place. You should label each of your hot spots with alt text to tell the screen reader where each hot spot takes the user. You can see an example of Yahoo!'s image map placed at top of their main web page.
Row and Column Headers - Checkpoint (g)
"Row and column headers shall be identified for data tables."
Cal Poly recommends that the use of frames be avoided. If you still choose to use data tables, you should always have the tables' headings defined. This lets the screen reader know what it is reading in each table. Tables used only for layout should NEVER have row and column headers.
Associating Data Cells and Header Cells - Checkpoint (h)
"Mark-up shall be used to associate data cells and header cells for data tables that have two or more logical levels of row or column headers."
Complicated data tables sometimes have more than one column or row header associated with each column or row. In this case, you must tell the screen reader which headers correspond to which column or row.
Frames - Checkpoint (i)
"Frames shall be titled with text that facilitates frame identification and navigation."
Frames must be titled correctly, and the title should reflect the frames' contents. The navigation frame should be called "navigation," the content frame should be called "main content," and so on.
Screen Flickering - Checkpoint (j)
"Pages shall be designed to avoid causing the screen to flicker with a frequency greater than 2 Hz and lower than 55 Hz."
People who have photosensitive epilepsy are susceptible to seizures if your web site contains flashing elements. Flickering is usually annoying to all users, and you should try to stay away from it all together. If you must have flickering elements, make sure they meet the guidelines.
Provide Text Only Pages as a Last Resort - Checkpoint (k)
"A text only page, with equivalent information or functionality, shall be provided to make a web site comply with the provisions of this part, when compliance cannot be accomplished in any other way. The content of the text only page shall be updated whenever the primary page changes."
Sometimes it is not possible to follow all these guidelines, and you must use a text only web site. You should NEVER resort to a text only web site before attempting to make your web site accessible. LIFT, a text transcoder that translates your web site to a text only web site, is a good tool if you have to resort to this method.
Scripts - Checkpoint (l)
"When pages utilize scripting languages to display content, or to create interface elements, the information provided by the script shall be identified with functional text that can be read by assistive technology."
The most predominant scripting language for the web is JavaScript. You should stay away from using Javascript to present important information such as navigation menus. Try to make your important content without Javascript, and use Javascript to make your content look more presentable. A good way to test this is to turn off JavaScripting to see if your web site is accessible and presents all its important information.
If you must use Javascript for important elements, all content that your Javascript generates should be accessible. A good way to test this out is to see if you can navigate your web site using your keyboard only.
Provide Links to Necessary Plug-Ins - Checkpoint (m)
"When a web page requires that an applet, plug-in, or other application be present on the client system to interpret page content, the page must provide a link to a plug-in or applet that complies with everything from Alternative Text to Scripts covered in this tutorial."
If you need your users to download a plug-in before viewing your content, you must provide a link to the plug-in, and the link itself must comply with Section 508 guidelines. The web site that the plug-in resides in must follow Section 508 guidelines as well.
Forms - Checkpoint (n)
"When electronic forms are designed to be completed on-line, the form shall allow people using assistive technology to access the information, field elements, and functionality required for completion and submission of the form, including all directions and cues."
Forms may get confusing if the user does not know what to input into each form field. You need to use additional HTML to tell the screen reader which labels go with which form elements.
Skip Repetitive Navigation Links - Checkpoint (o)
"A method shall be provided that permits users to skip repetitive navigation links."
If your navigation links are the first things that appear in your code, you will have to provide a skip navigation link. Sighted users can skip links by scanning past them on every web page. A person using a screen reader, however, would have to go through each link manually to get to your main content.
Timed Responses - Checkpoint (p)
"When a timed response is required, the user shall be alerted and given sufficient time to indicate more time is required."
You should tell your users when their session is about to time out if you employ this method. Disabled users may take longer to go through a web site, so they should have an option to request more time.