alt="xxxx" - isn't really "alternative", Options

[Alan T]

When I add alt to an image it always appears - it seems really to be *additional* rather than *alternative*.

Can I set it up so that it is a genuine alternative, ie so that people who see the image don't have to also read my description of it?

Alan ..............

[bragadocchio]

I read one place something someone called the telephone test. If you were describing the page to someone over the phone, and you got to the picture, what would you say about it. That's the alternative.

I'm not exactly sure what you mean by a "genuine alternative", but normally people won't read the alt text if they can see the image, unless they hover over it.

[Alan T]

By "genuine atlernative" I was meaning that one should appear (img or alt text), not both.

[bragadocchio]

You could use alt="" if you wanted, and it's recommended that you do that for spacer images and images that really are purely ornamental.

But I'm not sure why you wouldn't want to include the alt text for images in the absence of the picture appearing. If the picture is there, people won't see it unless they hover over the image.

[Adrian]

Alan, do you mean the little tooltip that pops up when you have the mouse hovering over an image?

If so, thats an IE bug effectively. The alt text is the text that should be displayed if the image is not. Hence it being alternative.

If you have a look in Opera, you will see alt text does not appear as a little flyout, instead in Opera (which does this technically more correctly) that action is prompted by the title attribute instead.

If thats not what you mean, then I don't really know what you are getting at.

[bwelford]

If you check a web page in Mozilla Firefox, you will see exactly the same treatment as in Opera. Alt texts do not show if the image is being displayed. Titles on images do show, since they are an accessibility feature for those who have a problem seeing the image, even though it is being displayed.

As Adrian said, unfortunately IE, which is used by the majority of surfers, handles this in the wrong way. There's not much you can do to correct this IE fault.

[Grumpus]

Yup. IE pretty much blows. The "alt" attribute comes from the olden days of the web. When it started out, modems transferred data at 300 bits per second. By the time Netscape hit the scene, though, the norm was 2400 (and 9600 was not too far down the road) but it was still very slow going when images were involved. Compression wasn't nearly as good and Compuserve's new GIF format was about as small as you could get. About 60K for a 320x240 image.

So, Netscape came equipped with a handy toggle switch that allowed you to "turn off images" when browsing. And, of course, the alt text was what showed when you were running in that mode.

Netscape and opera still handle images this way (but as pointed out, they will show the text on mouseover). So, back in the day, the attribute did make sense.

I know it doesn't really help ya, but figured the background info may be interesting.

G.

[Respree]

You could use alt=\"\" if you wanted, and it's recommended that you do that for spacer images and images that really are purely ornamental.

I use images for ornamental reasons (alt=""). Everytime I run my page through an HTML validator, it says my "alt" text is missing and I've made an 'error.'

I don't think this is a big deal, but wouldn't mind hearing other views on it.

[bragadocchio]

That's odd, Garrick.

I used the W3C validator to check this page, and got the same response you did:

http://www.utexas.edu/research/accessibili...decorative.html

But, the W3C are the ones who say that is valid html, and the right way to do it:

http://www.w3.org/TR/html4/struct/objects....s.html#adef-alt

Do not specify irrelevant alternate text when including images intended to format a page, for instance, alt=\"red ball\" would be inappropriate for an image that adds a red ball for decorating a heading or paragraph. In such cases, the alternate text should be the empty string (\"\"). Authors are in any case advised to avoid using images to format pages; style sheets should be used instead.

I use it because if someone uses a screen reader, if they don't have anything for alt text, then the screen reader will read the file name. If it's n empty string, the screen reader will move on past it.

[Respree]

Sorry, Bill. Completely my fault. You're right. Been a while since I came across that error and recollection was not correct. On the decorative images, I completely left the alt attribute out completely (as opposed to alt=""), which of course was causing the error I was thinking of.

Is this a big deal, leaving it (alt) out completely on these type of images?

[bragadocchio]

No problem.

The W3C validator did call it an error though, on the page I tested, even though it's their recommendation and standard.

The place where it may have the most drastic impact is with a screen reader, which will read the name of the file, letter-by-leter, over and over on a site that uses dozens of spacer gifs, like this:

h-t-t-p-:-/-/-w-w-w-.-e-x-a-m-p-l-e-.-c-o-m-/-i-m-a-g-e-s-/-s-p-a-c-e-r-.-g-i-f

After the second or third time, I suspect that becomes mind-numbingly boring.

I've seen suggestions that failing to include alt tags also slow the rendering of a page. It could be true, but I can't tell you that for certain.

[Respree]

Great. Thanks, Bill.

[Ron Carnell]

I used the W3C validator to check this page, and got the same response you did:

I ran that same utexas.edu page through the validator, Bill, and like you, received an error. It wasn't, however, the same error Garrick is claiming. Instead of saying the alt text is missing, the error indicated Line 26, column 107: there is no attribute "ALT"

And they're right, I think. Checking the source code, line 26 is a <td> tag with a background assigned. The alt attribute assigned to that tag (presumably applying to the background image?) is wrong and doesn't even make any contextual sense. No screen reader is going to describe background images any way.

I ran a few other pages with alt="" applied to <img> tag and received no errors.

[bragadocchio]

Thanks Ron,

It was difficult to tell with the code that showed on the W3C validation page. I assumed that the writer of a page about accessibility would know better, and didn't delve deeper into why the validator was making such an error.

Here's the summary view, when the validator is run:

Line 26, column 107: there is no attribute \"ALT\"

...sibility/graphics/greybarbg.gif\" alt=\"\">

Here's what we see on that line when we have the outline printed out, too:

26:  <td width=\"100%\" background=\"http://wwwtest.utexas.edu/research/accessibility/graphics/greybarbg.gif\" alt=\"\">

Good catch Ron

[Respree]

Other than the omission of alt="" for these ornamental images creating a validation error, is there any real harm to not correcting it? The pages seem to display fine to without it.