One of the ways to make your Web pages more usable is to give each graphic a caption that describes the image.
As a page is being downloaded, some Web browsers show a graphic's caption in the area occupied by the graphic.
If the graphic is being used as a menu button or for some other kind of navigational purpose, the caption enables your users to make use of it before the picture is downloaded. People who are using a slow Internet connection (56.6K or less) will appreciate the courtesy, especially if the graphic is large.
Text descriptions are also the only way a text-only Web browser such as Lynx can make any sense of graphics. If a graphic must be clicked to navigate your Web, it should have text that describes its purpose.
By supplying this text, you provide more information about the page's contents that search engines can utilize. The Google Images search service at images.google.com, which displays images matching one or more keywords, makes use of captions.
You also provide information that's essential for people with disabilities to use your Web site, which increases its accessibility.
The goal of accessibility, which is one of the hottest topics among Web designers today, is to ensure that a Web site can be used with screen readers and other assistive technology. By providing captions for each graphicespecially those which have hyperlinks associated with themyou expand the prospective audience for a site. Figure 3.6 shows a good example of a Web site that makes use of captions: the home page for Poynter Online, a resource for professional journalists published by the Poynter Institute.
Figure 3.6 Browsing without graphics.
On the Poynter home page shown in Figure 3.6, each of the items along the left edge is a hyperlinked graphic to a part of the site. Because the designer was so diligent about providing captions, the site can be used by the widest audience possible.
To add a caption to a graphic or edit an existing caption, follow these steps:
Double-click the graphic. The Picture Properties dialog box opens.
Click the General tab to bring it to the front. This tab can be used to change or replace a graphic, choose a hyperlink, or provide a caption and other descriptive information.
Type a succinct caption for the graphic in the Text field (or replace the existing caption, if one exists), as shown in Figure 3.7.
To see what your page looks like without graphics, most Web browsers can be configured to stop displaying them. In Internet Explorer 6, do the following:
Choose Tools, Internet Options.
The Internet Options dialog box opens.
Click the Advanced tab to bring it to the front.
Scroll down the Settings list until you find the Multimedia section.
Remove the check next to the Show Pictures check box.
Pictures will not be displayed for all Web pages that you load after that point, although some pages in your cache will still come up with graphics.
Figure 3.7 Adding a caption to a graphic.
You can turn picture display back on by selecting the Show Pictures check box.
The Web site Bobby at bobby.watchfire.com can test any page on the Web to see if it meets current standards for accessibility. If it doesn't, the site offers documentation and a frequently asked questions list for guidance on how to meet those standards.