Think of the
ALT text as a business opportunity, offering
a simple and easy-to-apply tool by which you can better reach a
proportion of users who might otherwise miss your message.
As someone else remarked:
On the WWW, accessibility comes
as part of the design - it costs you extra to eliminate it.
We see far too many examples of a negative approach,
by authors who treat
ALT only as
an incomprehensible chore to achieve formal compliance with
some legalistic rule for which they have no sympathy: by taking that
attitude, they are tossing a business opportunity out of the window,
and practically guaranteeing inferior results.
I'm not claiming here to be offering the one and only correct answer to any particular situation discussed. In each case, there will be quite a range of solutions that could get the desired message to readers of all kinds. There will also be a wide range of purported solutions (as seen repeatedly on the WWW) that quite unnecessarily fail in a range of browsing (and other web client) situations: this isn't about cases where the nature of the material itself precludes it being available - what is being objected to here is material that is inherently accessible being made pointlessly inaccessible.
My chief aim has been to bring the subject into the open; to provoke
reasoned discussion; and to address the many incomprehensible
ALT texts that I am seeing on the WWW. In doing so, I hope
also to demonstrate that the often repeated claim that "authoring also
for text-only users would cost us an unreasonable additional effort
which we cannot afford" is a mistake: this claim seems plausible only if
you don't know what it is that you are trying to say to your readers,
and have confused the presentation details (which in any case cannot be
closely controlled by writing HTML for the WWW) with the content of your
On the question of authoring style, there's some very instructive early discussion in the Style Guide for Online Hypertext at the W3C, with particular reference to Don't format for a particular browser and Avoid talking about the Mechanics.
The author of a book does not normally try to tell the reader how to read it, what light to read it in, how to use the fold-out insert etc. unless there were some very special reason to do so. You'd assume they already understand how to do that, or have the freedom to choose for themselves, wouldn't you? So, I would ask you to kindly not patronise your readers by implying that they don't know how to use their own WWW browser.
While it's true that at a time of explosive growth of the WWW, many readers will be newcomers and maybe not fully familiar with their browsers yet, your article on wild mushrooms isn't going to be improved by turning it into yet another browser-use tutorial. If there's some special requirement on your page, then I'd recommend you politely mention that browsers have features which address that special requirement; but keep in mind that they might not be using the same browser/platform that you use, and if you try to tell them how to use your browser, it's quite possible that you will confuse them.
I can't resist mentioning here the better-engineered
OBJECT element (offspring of the HTML3.0-draft
FIG), offering more-flexible opportunities
for fallback behaviours.
However, within the scope of
this note I am specifically dealing with the appropriate use of the
IMG tag. Indeed, use of the
is still beset by some strange anomalies in various browser versions.
There are many possible reasons. If you, as an author, assume that you know the reason (for example, if you assume that text mode is only used by people with a low disposable income, and therefore of no interest to you), then you will very likely exclude - and annoy - some people that you really would like to have as customers, even though you didn't realise it. Apart from that, if you are making available some textual information, then what would be the logic of fencing it away behind an impenetrable thicket of graphics-only?
One of the most important readers of your WWW page is the indexing
robot: it is, in effect, blind, and cannot understand your images. The
ALT text is an excellent way to help the robot and assist in getting
your page indexed appropriately. Some authors seem to prefer spending
lots of effort on composing META tags for the indexers - a
reasonable enough idea in itself - but that information isn't
usually conveniently accessible to text-mode readers, whereas effort
spent on your ALT texts rates to produce benefits for both kinds of
"reader" (caveat: it varies from one indexing service to another
whether they use
ALT texts or not).
been so much abuse of the META tags by some web-page providers, that
some indexers now ignore the META entirely, or apply strict
disqualification rules to avoid getting fooled by that kind of trickery.
With, by now, hundreds of millions of URLs on the WWW, you really
need every bit of help fron those indexers,
giving you an extra chance to reach readers who are specifically
interested in what you have to offer them. These are your "quality"
visitors, each one far more valuable to you than an army of readers who
might stumble onto your URL while "surfing".
1. The digital cellphone is now a commonplace. Increasingly, these cellphones are coming with a small display, and/or data socket to which a more elaborate display, for example a laptop or palmtop, can be connected. However, the data rate that is available is quite limited, compared with a wire telephone. (Personal opinion: I don't think WAP is the answer. There's a field of application where WAP is clearly useful: but it raises at least as many questions as it solves, and runs the risk of causing further fragmentation.)
2. In the Hitchhiker's Guide to the Galaxy by Douglas Adams, The Book is described as a handy device having a display about four inches square, capable of displaying any one of a million pages of information. It's clear that The Book is conceived as a self-contained system, as would be appropriate for the intergalactic traveller. Here in the real world, we have palmtops; and phones with integrated browsers such as the Nokia 9000 series. So, something rather like The Book, but giving access to not just a million pages of information stored within it, but the vast number of documents on the WWW.
Supporting a high-bandwidth wireless access service over wide areas of any country seems quite a way off yet, in spite of bandwidth-spread trials in limited areas.
A mention too of Wearable computers.
3. The Speaking Machine - not only for the blind. There are times when it's nice to rest the eyes, or they are concentrating on something else.
4. Some sceptics on the WWW usenet groups, when an unusual or futuristic presentation device is mooted, appear to believe that they gain some benefit by deliberately shutting out those unusual devices, rather than exploiting HTML's capability to put their information into every reader's browsing situation. This shows a very narrow minded and short sighted view, unworthy of the high principles of the WWW, quite apart from the practical (f)utility of such an approach.. Why "author for" a restricted reading situation, when HTML comes with a range of options that empower you to "author for" all reading situations? The oft-repeated phrase about "target audience" refers to those people to whom you are aiming your "topic of discourse": applying yet another layer of selectivity according to their browsing situation (except where the content by its very nature compels it) seems to be a misunderstanding of what "target audience" or "target readership" is about.
Even 0.01% of internet users is still a significant number
of individuals, especially if they just happened to be the people who
took an interest in your product: how can you be sure they're not?
Truly it has been said that many WWW pages have been
for arguing with customers, and things seem to be
getting worse rather than better.
Anyway, here's my very incomplete list of why readers might choose to use a text-only browser, or a graphics browser with auto image loading turned off.
Right, you clever authors that say text mode readers aren't worth bothering about: what was the common factor in all those users, apart from the fact that they use text mode (whether from choice or from necessity)? I reckon there wasn't one. Just because you think you know the "profile" of your target audience, does not mean that they will all of them fit that profile, all of the time. When you advertise in the wrong magazine, you merely miss some of your potential customers: no active harm is done. When you offer WWW readers something which, it turns out, they cannot read because it's been designed for a limited range of platforms, you have been actively rude to a potential customer. You only have to annoy them once, to send them to your competitors. Just one disgruntled customer can generate a lot of negative advertising, and lose you other potential customers.
I have to confess to having rather little direct experience of the kind of WWW problems encountered by blind readers, although I try to take an intelligent interest. The issues are a hot topic at the Web Accessibility Initiative area at W3C.
Frankly, many of the pages that I see on the WWW are so obviously in need of a degree of care and attention that would help all text-mode readers, and so often I have received the response from unsympathetic authors who refuse to show any consideration for what they perceive to be a small minority group; therefore I am concentrating on techniques that seem to be beneficial for all text mode readers, and by implication also for blind readers as well as for indexing robots, rather than convincing such sceptics to avoid putting their time and effort into techniques which damage the basic accessibility of which the WWW was designed to be capable. I hope my intentions in proceeding this way will not be misunderstood: I applaud those authors who would additionally like to take the time to make their documents even more accessible, and who are willing to follow appropriate guidelines.
Note that in HTML4.0 there are three or four attributes available for their respective purposes (I'm paraphrasing the HTML4.0 recommendation):
How best to use these mechanisms is still under active discussion in detail, but we can see that there is even less reason now to use the ALT attribute for mere descriptions of the image, in general.
For legacy browsers, the forerunner of the LONGDESC attribute was the D-link, pioneered by WGBH. However, it has recently been argued that these D-links should now be phased out, as they can be unnecessarily intrusive, and readers who want or need LONGDESC will get a browser which supports it.
I received an interesting email from someone who was attempting, unsuccessfully, to use FONT COLOR to get their ALT texts to contrast properly against their dark-ish background.
[Nowadays, I would recommend concentrating on use of CSS for this kind of purpose, but back then, this section was written to point-up some issues with HTML3.2 features.]
It's been my experience that the ALT text shows up in the same colour as is specified in the TEXT attribute of the BODY tag, or in some browsers if the image is a link then it will use the LINK or VLINK colour as appropriate.
FONT COLOR is dangerous in Netscape (4.* or earlier) anyway, because it cannot be disabled by choosing the "use my colors" option. Thus, the reader who is in a difficult browsing situation and trying to make matters better by controlling the colours themself, will get the author's chosen FONT COLOR displayed against the reader's choice of background. In some cases this makes text totally invisible. This issue is discussed in more detail in Warren Steel's FONT rant.
MSIE and Opera don't have this bug: when they are set to use the reader's colour scheme, it overrides FONT COLOR as well as the other colour attributes.
Because of this problem with Netscape versions, I would recommend avoiding FONT COLOR whenever possible. By now it should be enough to use CSS to suggest distinctive text presentations, based on colour and other properties, to improve the likelihood of of the affected text showing-up distinctively in a wide range of browsing situations, yet in ways that are less harmful to specialised access requirements.
Use of the colour attributes of the BODY tag, by comparison, is harmless, because browsers can override it when the reader finds it necessary. Of course, if you use a background image then its colour needs to be consonant with your BGCOLOR attribute.
I recommended my correspondent to set the basic colour choices for their page in the BODY attributes only. In my experience this gives good results with the ALT texts on a good range of browsers.
On frequent occasions, one meets authors who evidently suppose that the whole purpose of ALT texts is to serve as pop-ups when the reader passes their mouse over an image. This and other misunderstandings are evident in the following correspondence, which I quote here with my replies (in somewhat edited form).
Quite often when building a website I will have to use a transparent image to force the browser to correctly display the desired spacing.
I have to tell you frankly that I dislike this wording. On the WWW, the use of "force" is often unsuccessful, and there's nothing that says that you have to use transparent images or to force a browser to display a desired spacing. There's nothing wrong with making a web page that looks the way you want it to look, in the viewing situation that you have in mind; but it's best, to my way of thinking, if your HTML (and CSS) is also flexible enough that the design adapts itself smoothly and without fuss to a wide range of viewing situations in which it might find itself.
I never even considered putting an ALT tag on these images because nobody can even see them.
On a text browser, your assertion is untrue: the text browser has no idea what the image is about, whether it contains meaningful information or not. The ALT attribute is there to serve this purpose.
However, the Bobby program picks up on this and has flagged this as a problem.
Certainly; it will also count as an HTML syntax error that the mandatory ALT attribute has been omitted.
Your article seems to suggest that even these images should contain an ALT tag to explain the purpose.
Definitely not "to explain the purpose", no. The ALT attribute should supply alternative text, to use in place of (instead of) the image. Or, as another perceptively put it: "think of the alt text and the image as alternative ways of representing content".
If the image serves no purpose in the way of content then the alternative text would logically also be empty. In some situations it might be preferable to put a non-blank separator there, maybe a vertical bar or mid-dot.
To me, it would seem more annoying than valuable to have the description appear for a spacer every time a mouse is held over that part of the screen.
You're describing what is nowadays increasingly recognised to have been a browser bug. The ALT attribute was and is intended as a functional text-mode replacement for the image when - for whatever reason - the image is not being displayed. To display it, unsolicited, when the image is being displayed (e.g as a pop-up) is misleading, and can be counter-productive. (There are however some users who feel it beneficial to be able to read the alternative text at their option, so I'm not trying to say that browsers should not have such an option if they wish - just that it ought not to be the default behaviour.)
The optional TITLE attribute is available for providing
information about a resource, such as an image. It's this
text which is apt for display as e.g a pop-up.
If you wish to suppress the display of ALT text as a popup, at least
in browsers which honour this convention, then supply an empty
TITLE attribute, i.e
Fortunately in MSIE, and increasingly in other browsers, the TITLE attribute takes priority for this purpose. Netscape 4.* should not be used as a model of proper browser behaviour!
What would I even put there, "Spacer used to move text over to the right?"
ALT="" , or
ALT=" | " together with
would be my recommendation, until you can be persuaded to give up
this practice of trying to achieve precision page layout with this
kind of technique.
Even if you have no intention of using it yourself, the Lynx browser can be a useful tool to remind one of what a page "looks" (or sounds) like to some users. And indeed to indexing robots, which is also a significant consideration, no?
Original materials © Copyright 1994 - 2006 by A.J.Flavell