Originally Posted by Tess

What the heck are alt tags anyway? If you just place your cursor over one of our graphic ads in the sidebar for a second you'll see - for instance hold your cursor over the ad for "IDEAL" - you'll notice the words 'IDEAL' a newsletter for VA's pop up.

That's called a tooltip. Internet Explorer incorrectly displays the contents of the alt attribute as a tooltip, but it is the only modern browser to do so. If you want to provide tooltip text to your visitors, use the title attribute instead.

The title attribute should convey supplemental or advisory information only because tooltips will not be available to some visitors (keyboard only users, some handheld device users, visitors that rely on assistive technology...etc.). Alt text is primary content that should convey the same information as the image does. An element's alt attribute and title attribute should not have the same content.

Quote:

Alt tags should give a good, basic description of whatever the image actually IS. For instance, our VA directory ad in the sidebar has an alt tag that is descriptive enough that search engine spiders understand what the image represents. And it doesn't hurt at all that the alt tag includes a few solid keywords.

Alt text should not necessarily describe an image. The alt attribute should serve the same purpose and communicate the same information as the image. If an image contains words relevant to the content, its alt text should include those words. If an image serves a purpose, like a search button, its alt text should convey that function. Images that are purely decorative, like rounded corners, should have null (empty) alt attributes.

Search engines do not heavily weigh alt and title attributes because they are frequently abused. Using these attributes correctly will help you reach a larger audience.

HTH,
CK