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Alternative text descriptions for all images
Setek




msg:3705901
 1:50 am on Jul 24, 2008 (gmt 0)

I've recently become embroiled in a debate at work about alternative text descriptions. Now, while I agree that image elements should have meaningful descriptions attached, I also believe that images that are presentational in nature should have empty descriptions (
alt="") so that it is not read out by aural narration devices (where simply not having an alt defined will cause the device to read aloud the filename, thus still wasting time.)

So my belief extends to images that have been added to copy that doesn't contribute anything to the copy itself; what essentially happens when someone says "that page looks boring, add an image in." My example was a page about timetables and maps having an image with the alternative description, "Student sitting at a cafe with laptop."

I believe that an image such as this, which has nothing to contribute to the copy (no message is gained by its presence, and likewise, no message is lost by its removal) should have empty alternative descriptions. It is overly verbose and a waste of precious time -- it takes a lot longer for a user of aural assistive devices to disregard the image than it does a visual user.

What does everybody else think?

 

DrDoc




msg:3706433
 4:09 pm on Jul 24, 2008 (gmt 0)

I think that is a very accurate observation. Certainly, important images should have an intelligent alternate text specified. Presentational and "fluff" images can reasonably be left with an empty
alt attribute.
JamieBrown




msg:3706502
 5:01 pm on Jul 24, 2008 (gmt 0)

While I'd definitely agree that "Student sitting at a cafe with laptop." is a waste of space, leaving some ALT attributes empty can be a missed opportunity for SEO.

I would possibly put something like "Student looking at rail timetables" or even just "Rail timetables image".

This may be a topic where SEO doesn't quite agree with Accessibility best practice though - certainly from a screen reader POV having no ALT tag on this image makes browsing easier.

Setek




msg:3706979
 4:36 am on Jul 25, 2008 (gmt 0)

Yeah JamieBrown, I don't think accessibility and SEO really see eye to eye on that one -- my brain immediately balks at the thought and says "that's very opportunistic, and underhanded, not to mention the fact that it's just plain wrong."

:)

JamieBrown




msg:3707068
 8:05 am on Jul 25, 2008 (gmt 0)

LOL! You're probably right! Its a shame, because on most topics SEO agrees very much with Accessibility.

Setek




msg:3709983
 5:44 am on Jul 29, 2008 (gmt 0)

I know there aren't that many readers of this forum... it seems to be an oft-overlooked topic... but is there anyone else that has any opinion?

encyclo




msg:3710175
 12:31 pm on Jul 29, 2008 (gmt 0)

images that are presentational in nature should have empty descriptions (alt="") so that it is not read out by aural narration devices

Quite right - and you could take it a step further: presentational images should not be in the page markup at all, they should be included as background images via CSS whenever possible.

As for the SEO aspect, I don't buy it - alternative text is not a substitute for on-page visible text, unless you're trying the largely ineffectual keyword-stuffing technique, or if the image is used as a link - in which case, the alt text should be descriptive in the same way as any other text anchor. Inserting presentational images as background makes the page lighter and more focussed for the search engines.

So there's no real debate - apart from the question as to whether the images are really presentational or not. If they are in any way descriptive or offer supplementary information not contained in the surrounding text, then you must provide adequate alternative information.

JamieBrown




msg:3710405
 4:47 pm on Jul 29, 2008 (gmt 0)

As for the SEO aspect, I don't buy it

Unfortunately, it does work - on pages that have very little text and where text can't be easily implemented, putting carefully targeted content into ALT tags can make a very positive difference to the SERPs.

I'm not talking about spammy keyword stuffing techniques, but just making the ALT tags a little more descriptive and keyword rich.

D_Blackwell




msg:3710619
 8:36 pm on Jul 29, 2008 (gmt 0)

Unfortunately, it does work.....putting carefully targeted content into ALT tags can make a very positive difference to the SERPs.

I would not consider this form of SEO to be 'unfortunate'. It is (IMO) an essential image SEO tool. File names and alt descriptions both help with ranking for image searches. I have taken to branding all images above thumbnail size so that when they show up in the search engines they are less likely to be stolen, and more likely to bring me some extra traffic or to license/sell images. I have also taken to downgrading the file names and alt/title for thumbs and concentrating on giving the most value to the larger image presentations.

presentational images should not be in the page markup at all, they should be included as background images via CSS whenever possible.

I probably use less 'presentational' images than most but fully agree to avoid using <img> and placing as background-image: It's usually not that difficult once the habit is developed. This eliminates the accessibility conflict entirely in many cases and is 'best practice'. It wouldn't even occur to most designers but should be highlighted bullet point in 'the handbook':))

I have a high interest in in this forum, though my skills remain limited. The biggest problem is that everything has to be learned and done on my time and for my own interests. Very few clients will pay a nickel extra for the benefit of these skills or knowledge. Mostly I work on my own sites now, but I have the same ROI issues - there isn't any. I work on improving these skills where and when I can for my own reasons.

encyclo




msg:3710636
 8:48 pm on Jul 29, 2008 (gmt 0)

Using alt text does have an influence, but it's a poor substitute for simply displaying the same text on-screen in a paragraph rather than hidden via an alt attribute. The search engines benefit in both cases, but when using standard text then all your users benefit too.

So my argument remains that keyword-stuffing the alt attribute is sub-optimal compared to adapting the design to allow for image-plus-text - when dealing with "meaningful" images, not decorative ones. Think newspaper/magazine photo captioning, put the image title in a hx element above and the caption below.

JamieBrown




msg:3710942
 8:08 am on Jul 30, 2008 (gmt 0)

Using alt text does have an influence, but it's a poor substitute for simply displaying the same text on-screen in a paragraph rather than hidden via an alt attribute. The search engines benefit in both cases, but when using standard text then all your users benefit too.

100% agree - the text option is much better and should be used where-ever possible. Unfortunately on all sites its just not possible! :-)

I would not consider this form of SEO to be 'unfortunate'.

You're right - badly worded!

JerryOdom




msg:3715185
 11:14 pm on Aug 4, 2008 (gmt 0)

In the recent mobile device development books I've been using the authors like to state that you should use alt text for devices that don't support images.

I tend to agree that the alt should only be important when the image is relevant and some information would be lost by a reader not having access to it. But non-important image could be included for the sake of comleteness.(page authors discretion)

Setek




msg:3715269
 1:17 am on Aug 5, 2008 (gmt 0)

Thanks for everyone's replies, it's been good to get a sample of what everyone else thinks.

I'm glad I was on the right track, and not completely alone in my point of view :)

Thanks again, and I'll always welcome any more thoughts!

encyclo




msg:3717461
 11:02 am on Aug 7, 2008 (gmt 0)

You might be interested in some of the examples shown in the HTML5 draft specification:

[whatwg.org...]

Setek




msg:3717497
 11:55 am on Aug 7, 2008 (gmt 0)

! Thanks encyclo, that was pretty much what I was looking for :)

4.7.2.1.6. A purely decorative image that doesn't add any information but is still specific to the surrounding content

[...]

In these cases, the alt attribute must be present but its value must be the empty string.


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