Re: [whatwg] ALT and equivalent representation
What is the advantage of cutting an image to parts and having the browser show them as one by putting them aside? I would rather use one big image in the first place. Chris -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Shannon Sent: Monday, April 21, 2008 3:18 AM To: WHAT working group Cc: Bill Mason; Smylers Subject: Re: [whatwg] ALT and equivalent representation Fallback for current browsers is something I overlooked but it is easy to do: altgroup id=hippo value=Hippopotamus img src=hippo_head.png altgroup=hippo alt=Hippopotamusimg src=hippo_tail.png altgroup=hippo With the alt simply being overridden by altgroup in a HTML5 browser. Shannon
Re: [whatwg] ALT and equivalent representation
Or even img src=11100 alt=3/5 -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Bill Mason Sent: Saturday, April 19, 2008 10:14 PM To: Simon Pieters Cc: [EMAIL PROTECTED] Subject: Re: [whatwg] ALT and equivalent representation Simon Pieters wrote: For instance it would be reasonable to use two images -- a filled star and an unfilled star -- to represent a rating of something: pRating: img src=1img src=1img src=1img src=0img src=0/p You'd want the text version to be: Rating: 3/5 There would probably be the argument for more literal interpretations (not that I would automatically subscribe to any of them as correct), such as Rating: (3 black stars in unicode) (2 white stars in unicode) Rating: *** (or 3 stars of some sort in unicode) (if the context of the page already established that ratings were on a scale of 5) Hence: pRating: img src=1 alt=3/5img src=1 altimg src=1 altimg src=0 altimg src=0 alt/p Or pRating: img src=1 alt=#9733;img src=1 alt=#9733;img src=1 alt=#9733;img src=0 alt=#9734;img src=0 alt=#9734;/p pRating: img src=1 alt=*img src=1 alt=*img src=1 alt=*img src=0 altimg src=0 alt/p -- Bill Mason Accessible Internet [EMAIL PROTECTED] http://accessibleinter.net/
Re: [whatwg] ALT and equivalent representation
ALTGROUP is a dirty trick; if you insist on having the images separate, which you really should not do, you can have image alt=3/5 img src=part1.png /img src=part2.png /img src=part3.png /image This extension would be closer to the meaning IMHO. Otherwise, what happens if the images that belong to the same ALTGROUP of yours are not contiguous? Chris -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Shannon Sent: Sunday, April 20, 2008 1:30 PM To: whatwg@lists.whatwg.org Subject: Re: [whatwg] ALT and equivalent representation What about this as a possible solution? img src=part1.png altgroup=rating img src=part2.png altgroup=rating img src=part3.png altgroup=rating altgroup id=rating value=3/5 I don't think this would raise any serious implementation issues as the logic is quite simple; If all elements in an altgroup are unavailable then display the value of the altgroup tag. The alt attribute would then be optional where altgroup is defined but required in all other cases. Shannon
Re: [whatwg] ALT and equivalent representation
On Mon, Apr 28, 2008 at 2:04 PM, Křištof Želechovski [EMAIL PROTECTED] wrote: What is the advantage of cutting an image to parts and having the browser show them as one by putting them aside? I would rather use one big image in the first place. Chris On my company's web site, our header image is split into two parts. One is floated left, one is floated right, and they sit on top of a repeated background image. This lets the entire header smoothly scale to the width of the viewport. Since the two images are just pieces of a complete header image, the alt text should only show up once. I just put the alt on the first image and use alt= on the second, but it would be nice to have a canonical answer to this. Note: I am *perfectly fine* with not introducing a new element or new attributes. I feel that just putting an alt text on one of the images and leaving the others blank is sufficiently semantic. However, I do believe that this is a useful case to address in the alt text guidelines. ~TJ
Re: [whatwg] ALT and equivalent representation
Shannon wrote: Smylers wrote: What advantage does it have over Simon's proposal? Simon's suggestion has the obvious advantage that it already works with current browsers. Smylers Simon's suggestion is no different from the original proposal, the idea that alt can be optional on some images. I think you've misunderstand Simon's suggestion, which was: pRating: img src=1 alt=3/5img src=1 altimg src=1 altimg src=0 altimg src=0 alt/p Note /all/ the img elements have alt attributes, the point is the alternative text for the group is expressed by the first alt attribute. It's thus actually the same as the fallback you propose: Fallback for current browsers is something I overlooked but it is easy to do: altgroup id=hippo value=Hippopotamus img src=hippo_head.png altgroup=hippo alt=Hippopotamusimg src=hippo_tail.png altgroup=hippo With the alt simply being overridden by altgroup in a HTML5 browser. -- Benjamin Hawkes-Lewis
Re: [whatwg] ALT and equivalent representation
Benjamin Hawkes-Lewis wrote: I think you've misunderstand Simon's suggestion, which was: pRating: img src=1 alt=3/5img src=1 altimg src=1 altimg src=0 altimg src=0 alt/p Note /all/ the img elements have alt attributes, the point is the alternative text for the group is expressed by the first alt attribute. It's thus actually the same as the fallback you propose: Not the same thing at all. There is no direct association between the elements so there is no way a validator or browser would know the difference between a missing/empty alt and an optional one - thus making ALL use of alt optional as far as formal validation is concerned. If you are implying a group can be denoted by being at the same block level or in the correct order in the stream (no intervening images) then I doubt that would work in practice. Shannon
Re: [whatwg] ALT and equivalent representation
On Mon, 21 Apr 2008 08:48:06 +0200, Shannon [EMAIL PROTECTED] wrote: Benjamin Hawkes-Lewis wrote: I think you've misunderstand Simon's suggestion, which was: pRating: img src=1 alt=3/5img src=1 altimg src=1 altimg src=0 altimg src=0 alt/p Note /all/ the img elements have alt attributes, the point is the alternative text for the group is expressed by the first alt attribute. It's thus actually the same as the fallback you propose: Not the same thing at all. There is no direct association between the elements so there is no way a validator or browser would know the difference between a missing/empty alt and an optional one - thus making ALL use of alt optional as far as formal validation is concerned. Automated conformance checking of alt is not possible anyway. It needs human investigation with knowledge of the context in which the image in question finds itself. Therefore, extra markup for aiding conformance checking is not helping anyone -- on the contrary it adds more cruft for the person checking for conformance. As for browsers, the goal there is to replace all images with their replacement text, and the result of both the above and your proposal would be: Rating: 3/5 Hence, your extra markup isn't helping browsers either. Moreover, it doesn't degrade nicely with existing UAs unless the author goes an extra mile and add alt to all the images (in which case the extra markup becomes pointless again). -- Simon Pieters Opera Software
Re: [whatwg] ALT and equivalent representation
Shannon wrote: Benjamin Hawkes-Lewis wrote: I think you've misunderstand Simon's suggestion, which was: pRating: img src=1 alt=3/5img src=1 altimg src=1 altimg src=0 altimg src=0 alt/p Note /all/ the img elements have alt attributes, the point is the alternative text for the group is expressed by the first alt attribute. It's thus actually the same as the fallback you propose: Not the same thing at all. There is no direct association between the elements so there is no way a validator or browser would know the difference between a missing/empty alt and an optional one - thus making ALL use of alt optional as far as formal validation is concerned. If you are implying a group can be denoted by being at the same block level or in the correct order in the stream (no intervening images) then I doubt that would work in practice. In /the fallback you propose/ there is no direct association between the images either. In Simon's example, the first image is given an alt of 3/5. The other images are given an alt of . (I'm not sure how the syntax Simon's using fits into http://www.w3.org/html/wg/html5/#attributes1 , but at any rate he's not omitting alt.) So this is the same as: pRating: img src=1 alt=3/5img src=1 alt=img src=1 alt=img src=0 alt=img src=0 alt=/p In this case non-image-rendering user agents should (and, equally importantly, will) render: Rating: 3/5 or something like: Rating: image 3/5 The information that the images are a group would appear to be of only marginal importance in this particular example. I can think of cases where it might be important however: for example, if a content image like a photo or a diagram were sliced up for some reason and the user wanted to copy it elsewhere. The case of Google's logo, described earlier in the thread, is possibly an example of this. But whether we need a mechanism for denoting differing img elements combine to form a single image is a very different question from whether alt should be optional or required. You seem to be conflating them. -- Benjamin Hawkes-Lewis
Re: [whatwg] ALT and equivalent representation
Shannon writes: Shannon wrote: What about this as a possible solution? img src=part1.png altgroup=rating img src=part2.png altgroup=rating img src=part3.png altgroup=rating altgroup id=rating value=3/5 I don't think this would raise any serious implementation issues as the logic is quite simple; Smylers wrote: What advantage does it have over Simon's proposal? Simon's suggestion has the obvious advantage that it already works with current browsers. Simon's suggestion is no different from the original proposal, the idea that alt can be optional on some images. No, Simon was specifying an alt attribute on each image (see below). Fallback for current browsers is something I overlooked but it is easy to do: altgroup id=hippo value=Hippopotamus img src=hippo_head.png altgroup=hippo alt=Hippopotamus img src=hippo_tail.png altgroup=hippo With the alt simply being overridden by altgroup in a HTML5 browser. That still doesn't entirely work with current browsers, because -- unlike Simon's proposal -- you have no alt atttribute at all on the tail. That will provoke image-less browsers into using heuristics to guess what the most appropriate alternative representation is. Whereas in this case the most appropriate alternative is clearly to have nothing, so the author should unambiguously indicate that with alt=. That's also easy to do; it makes your suggestion be: altgroup id=hippo value=Hippopotamus img src=hippo_head.png altgroup=hippo alt=Hippopotamus img src=hippo_tail.png altgroup=hippo alt= For comparision, here's the mark-up following Simon's suggestion: img src=hippo_head.png alt=Hippopotamus img src=hippo_tail.png alt= Note that your suggestion is a superset of his: in order to get yours to work with existing browsers you have to do all of his anyway! So you are effectively asking an author to firstly do something which works in all known current browsers and _then_ put additional work in doing something which will make _no difference whatsoever_ to how the content is presented in any browser at all. Authors are unlikely to be motivated to do that. Shannon writes: Benjamin Hawkes-Lewis wrote: But whether we need a mechanism for denoting differing img elements combine to form a single image is a very different question from whether alt should be optional or required. You seem to be conflating them. How can img alt or img alt= not be related to making alt optional? Because whether the alt attribute is required in all cases (or only required in those where it's possible to provide a plausible alternative[*0]) the above will be allowed either way. Including an alt attribute and setting it to the empty string (which is what the above does) _is_ including an alt attribute; it's specifically saying that the image doesn't convey anything which isn't already conveyed elsewhere on the page, so for imageless browsing the most appropriate action is to omit it entirely from the content. [*0] Note it isn't 'optional', in the sense that at no point does the author have any option as to whether to include it or not; the spec makes it clear that if the author can provide it then she must. Once alt text becomes optional then it is likely that many designers/templates/wysiwyg applications will simply insert alt= into every image to pass validation without consideration ... But that's what we currently have with HTML 4 validation! alt= is already allowed (and indeed is useful in many circumstances). It is this situation I am trying to avoid. Too late! But it's _also_ what HTML 5 is trying to lessen. One way to improve the situation is for people (and tools) _not_ to unthinkingly insert alt= in situations where that _isn't_ appropriate; where it's impossible to know what appropriate alt text is then it's better to leave it out entirely, so as to distinguish these cases. A valid document should provide valid alt information, not empty ones. The spec goes to some length to list different situations in which images are used and explains why alt= is the right thing for some of those. Please could you elaborate on each of those explaining why the spec is wrong and what would be more appropriate alt text than alt=. Smylers
Re: [whatwg] ALT and equivalent representation
Benjamin Hawkes-Lewis wrote: But whether we need a mechanism for denoting differing img elements combine to form a single image is a very different question from whether alt should be optional or required. You seem to be conflating them. How can img alt or img alt= not be related to making alt optional? Both represent a total lack of information with no explicit relationship to any other element. There is no way a parser can resolve whether this information is supplied previously or not. If the parser can't tell then it can't validate the alt requirement - thereby mandating that alt (that is the text, not the empty attribute) be optional for a conforming document (as far as a validator knows anyway). Once alt text becomes optional then it is likely that many designers/templates/wysiwyg applications will simply insert alt= into every image to pass validation without consideration for blind users. It is this situation I am trying to avoid. A valid document should provide valid alt information, not empty ones. An altgroup supports this - empty alt tags do not. Shannon
Re: [whatwg] ALT and equivalent representation
Smylers wrote: Bill Mason writes: Simon Pieters wrote: For instance it would be reasonable to use two images -- a filled star and an unfilled star -- to represent a rating of something: p Rating: img src=1 img src=1 img src=1 img src=0 img src=0 /p You'd want the text version to be: Rating: 3/5 There would probably be the argument for more literal interpretations such as Rating: (3 black stars in unicode) (2 white stars in unicode) You could do that, and you could also use meter to denote 3/5. But that's irrelevant -- Simon's example of alt=3/5 clearly is a genuine alternative way of representing the same information as the images do, and authors should be free to decide that's the text representation they wish to use. My point was only that what an author would want the text version to be is open to interpretation, not that the suggested text and how the alt attributes would be defined to produce that result was not a valid alternative. To think about it slightly differently, obviously it would be possible to represent a rating with a single image containing 5 stars of the appropriate colours; the author would just need to pre-compose the relevant images for each possible rating, in which case 3/5 could be implemented as: img src=3_5 alt=3/5 And in that case the alt text of 3/5 is acceptable, and clearly in the right place. Deciding instead to achieve this as Simon suggested above (have just 2 images and to display each rating by combining 5 instances of those images) is an implementation detail. There are benefits to each. HTML 5 shouldn't bless either of them as being 'preferred'. I don't recall suggesting that anyhow. And since with images enabled both implementations render identically it follows that alt text appropriate in one implementation is just as appropriate in the other. So what Simon suggested does make sense: when several images are combined to convey something as a whole, it should be a valid alternative to put text conveying the whole on any one of them, marking the rest with empty alt text. And I actually lean toward agreeing with that suggestion. -- Bill Mason Accessible Internet [EMAIL PROTECTED] http://accessibleinter.net/
Re: [whatwg] ALT and equivalent representation
What about this as a possible solution? img src=part1.png altgroup=rating img src=part2.png altgroup=rating img src=part3.png altgroup=rating altgroup id=rating value=3/5 I don't think this would raise any serious implementation issues as the logic is quite simple; If all elements in an altgroup are unavailable then display the value of the altgroup tag. The alt attribute would then be optional where altgroup is defined but required in all other cases. Shannon
Re: [whatwg] ALT and equivalent representation
Shannon wrote: What about this as a possible solution? img src=part1.png altgroup=rating img src=part2.png altgroup=rating img src=part3.png altgroup=rating altgroup id=rating value=3/5 I don't think this would raise any serious implementation issues as the logic is quite simple; If all elements in an altgroup are unavailable then display the value of the altgroup tag. The alt attribute would then be optional where altgroup is defined but required in all other cases. I think it would be more logical for the specification to support the common, existing, reasonable authoring practices than go through the expense of introducing both a new attribute and a new element. -- Bill Mason Accessible Internet [EMAIL PROTECTED] http://accessibleinter.net/
Re: [whatwg] ALT and equivalent representation
Shannon writes: What about this as a possible solution? img src=part1.png altgroup=rating img src=part2.png altgroup=rating img src=part3.png altgroup=rating altgroup id=rating value=3/5 I don't think this would raise any serious implementation issues as the logic is quite simple; What advantage does it have over Simon's proposal? Simon's suggestion has the obvious advantage that it already works with current browsers. Smylers
Re: [whatwg] ALT and equivalent representation
Shannon wrote: What about this as a possible solution? img src=part1.png altgroup=rating img src=part2.png altgroup=rating img src=part3.png altgroup=rating altgroup id=rating value=3/5 I don't think this would raise any serious implementation issues as the logic is quite simple; Bill Mason wrote: I think it would be more logical for the specification to support the common, existing, reasonable authoring practices than go through the expense of introducing both a new attribute and a new element. Yes this proposal requires a new tag and attribute but that is a lot less disruptive than giving designers an easy way to opt out of accessibility (while still claiming compliance). I'd like to believe that designers would do the right thing without being told but I know for a fact most of them don't. The alt requirement for w3c validation is what got me using them in the first place so I know it's having some effect. Smylers wrote: What advantage does it have over Simon's proposal? Simon's suggestion has the obvious advantage that it already works with current browsers. Smylers Simon's suggestion is no different from the original proposal, the idea that alt can be optional on some images. I've already explained why I consider that a dangerous step backwards from an accessible web. Fallback for current browsers is something I overlooked but it is easy to do: altgroup id=hippo value=Hippopotamus img src=hippo_head.png altgroup=hippo alt=Hippopotamusimg src=hippo_tail.png altgroup=hippo With the alt simply being overridden by altgroup in a HTML5 browser. Shannon
Re: [whatwg] ALT and equivalent representation
Shannon wrote: To make matters worse some browsers display the alt tag while waiting for images to come from the server and this creates visual artifacts that designers and clients generally consider undesirable. That's a feature not a bug. Many users are on slow connections. The end result of this is that alt tags tend to be seen as a burden by the majority of web designers I've met. Yes, web designers generally have very little attachment to quality. Also these are not government sites or contractors with mandated accessibility, and as far as I know there is no law requiring corporate sites to provide alternative text for blind users. IANAL, but laws aimed at businesses tend to talk in terms of prohibiting discrimination rather than drilling down to the techniques used to provide equivalent access (which is a good thing, since it allows techniques to improve). Whether there's any sort of legal obligation to provide text equivalents depends both on your jurisdiction and how crucial the alternative text is to the general accessibility of the service provided by the site. See for example: http://www.jimthatcher.com/law-target.htm http://www.jimthatcher.com/law-target2.htm http://juicystudio.com/article/web-accessibility-dda.php The ONLY business justification I have for using alt tags is that a w3c valid site REQUIRES them and this may increase the sites Google rank (which is just speculation really). I'd have thought an art gallery would benefit from getting their images into image search engines. http://googlewebmastercentral.blogspot.com/2007/12/using-alt-attributes-smartly.html I think this is a case where logic must give way to corporate consideration, as public and charitable sites would probably use alt tags without being told, but 95% of the mainstream internet will not - given half a chance. The rationale for making alt optional in certain cases is to increase accessibility in those cases. Now I don't really buy the reasoning for those cases, but I do not think the spec should sacrifice the accessibility of those cases (however it's best provided) on the altar of evangelising providing text equivalents through a validator. -- Benjamin Hawkes-Lewis
Re: [whatwg] ALT and equivalent representation
On Fri, 18 Apr 2008 20:30:12 +0200, Philip Taylor [EMAIL PROTECTED] wrote: What should happen for 'tracker' images? (i.e. img src=http://evil.google.com/user-track.php?site=97519340; width=1 height=1 alt=???) As some examples, Geocities has alt=setstats, someone has alt=statystyka, someone has alt=CrawlTrack: free crawlers and spiders tracking script for webmaster- SEO script -script gratuit de détection des robots pour webmaster, etc, and those examples do not help users who are seeing the alt text. Such images are pretty common, and they're not going to go away, so we should minimise their harm by saying alt= is appropriate. None of the cases in the spec seem to cover this case yet. Moreover, such images often use width=0 height=0, but that's invalid per HTML5, which seems a bit unhelpful. google.com is splitting the image up to fit it in a layout table, which is non-conforming HTML5; but there are other more legitimate reasons for having several img elements representing a single piece of text, and in those cases it seems sensible to put alt=all the text on one image and alt= on the others. Should HTML5 be changed to accept this? For instance it would be reasonable to use two images -- a filled star and an unfilled star -- to represent a rating of something: pRating: img src=1img src=1img src=1img src=0img src=0/p You'd want the text version to be: Rating: 3/5 Hence: pRating: img src=1 alt=3/5img src=1 altimg src=1 altimg src=0 altimg src=0 alt/p -- Simon Pieters Opera Software
Re: [whatwg] ALT and equivalent representation
On Apr 19, 2008, at 07:19, Shannon wrote: The end result of this is that alt tags tend to be seen as a burden by the majority of web designers I've met. Of course. Once you're thinking in terms of wanting to publish and image, producing text *in addition* to the image is a burden. The ONLY business justification I have for using alt tags is that a w3c valid site REQUIRES them and this may increase the sites Google rank (which is just speculation really). If you take the requirement out to use them on every image in a valid site then you take away much of my argument for using them at all. Instead of having a layer of validitity speculation in between, couldn't you make the point that alt helps with SEO? To me linking alt and SEO directly is more to the point and more honest, too. -- Henri Sivonen [EMAIL PROTECTED] http://hsivonen.iki.fi/
Re: [whatwg] ALT and equivalent representation
Henri Sivonen wrote: Instead of having a layer of validitity speculation in between, couldn't you make the point that alt helps with SEO? To me linking alt and SEO directly is more to the point and more honest, too. Whoa, don't do that! They'll just insist on you stuffing 100 characters worth of keywords in there. You can add insanity to the problems facing blind users on the web! Shannon
Re: [whatwg] ALT and equivalent representation
Shannon wrote: The ONLY business justification I have for using alt tags is that a w3c valid site REQUIRES them and this may increase the sites Google rank (which is just speculation really). If you take the requirement out to use them on every image in a valid site then you take away much of my argument for using them at all. In many juristictions, a company can face legal action if its website is not accessible per some standard or set of standards. This is the business justifaction I usually use; here in the UK, the Disability Discrimination Act[1] is the relevant reference. [1]http://www.webcredible.co.uk/user-friendly-resources/web-accessibility/uk-website-legal-requirements.shtml
Re: [whatwg] ALT and equivalent representation
Philip Taylor wrote: I believe the company logo case is also unclear in the spec. See e.g. http://www.google.com/ (when it's not a special day) - the image is simply the word Google (as a page heading, so it should probably be in h1), so common sense says it should have alt=Google. The spec phrase Icons: a short phrase or label with an alternative graphical representation sounds like it might apply here, but none of the cases in that section seems to work: in particular, I don't think the logo is being used to represent the entity would apply, because the purpose of the image is not to represent the entity (as it would be in e.g. a list of search engines that shows small images of all their logos so you can choose your favourite), and instead its purpose is to tell users what site they are on (and to make it look prettier). I would disagree with this assessment. A definition of logo that I submit as both typical and accurate is a graphic representation or symbol of a company name, trademark, abbreviation, etc., often uniquely designed for ready recognition [1]. Whether or not the logo is standing alone or has a surrounding context of other logos is not relevant to whether or not it is performing a representation function. Even if your assessment is correct, I believe my suggestion for clarifying 'equivalent representation' would apply to your situation in any event. [1] http://dictionary.reference.com/browse/logo -- Bill Mason Accessible Internet [EMAIL PROTECTED] http://accessibleinter.net/
Re: [whatwg] ALT and equivalent representation
Simon Pieters wrote: For instance it would be reasonable to use two images -- a filled star and an unfilled star -- to represent a rating of something: pRating: img src=1img src=1img src=1img src=0img src=0/p You'd want the text version to be: Rating: 3/5 There would probably be the argument for more literal interpretations (not that I would automatically subscribe to any of them as correct), such as Rating: (3 black stars in unicode) (2 white stars in unicode) Rating: *** (or 3 stars of some sort in unicode) (if the context of the page already established that ratings were on a scale of 5) Hence: pRating: img src=1 alt=3/5img src=1 altimg src=1 altimg src=0 altimg src=0 alt/p Or pRating: img src=1 alt=#9733;img src=1 alt=#9733;img src=1 alt=#9733;img src=0 alt=#9734;img src=0 alt=#9734;/p pRating: img src=1 alt=*img src=1 alt=*img src=1 alt=*img src=0 altimg src=0 alt/p -- Bill Mason Accessible Internet [EMAIL PROTECTED] http://accessibleinter.net/
Re: [whatwg] ALT and equivalent representation
Bill Mason writes: Simon Pieters wrote: For instance it would be reasonable to use two images -- a filled star and an unfilled star -- to represent a rating of something: p Rating: img src=1 img src=1 img src=1 img src=0 img src=0 /p You'd want the text version to be: Rating: 3/5 There would probably be the argument for more literal interpretations such as Rating: (3 black stars in unicode) (2 white stars in unicode) You could do that, and you could also use meter to denote 3/5. But that's irrelevant -- Simon's example of alt=3/5 clearly is a genuine alternative way of representing the same information as the images do, and authors should be free to decide that's the text representation they wish to use. To think about it slightly differently, obviously it would be possible to represent a rating with a single image containing 5 stars of the appropriate colours; the author would just need to pre-compose the relevant images for each possible rating, in which case 3/5 could be implemented as: img src=3_5 alt=3/5 And in that case the alt text of 3/5 is acceptable, and clearly in the right place. Deciding instead to achieve this as Simon suggested above (have just 2 images and to display each rating by combining 5 instances of those images) is an implementation detail. There are benefits to each. HTML 5 shouldn't bless either of them as being 'preferred'. And since with images enabled both implementations render identically it follows that alt text appropriate in one implementation is just as appropriate in the other. So what Simon suggested does make sense: when several images are combined to convey something as a whole, it should be a valid alternative to put text conveying the whole on any one of them, marking the rest with empty alt text. Smylers
[whatwg] ALT and equivalent representation
Today in IRC a discussion lead to a hypothetical example that didn't fit easily into the spec's current requirements for the alt attribute. The example was a case of a hacker who replaces the Google logo on google.com with an image only containing the text WE HACKED YOUR SERVERS. We assume the hacker cares enough about accessibility to set the alt attribute to the same text. Since the image is no longer the company logo, it falls outside the logo discussion in the Icons requirement for alt. The new image would appear to fall into the phrase or paragraph with an alternative graphical representation requirement. The spec's current language that the image is something [that] can be more clearly stated in graphical form something doesn't fit well because this hypothetical image is not 'more clear' -- it's equivalent. I would like to suggest that the language here somehow encompass that an image that is an equivalent statement to the phrase or paragraph also falls under this requirement. Perhaps something like: Sometimes something can be more clearly stated in graphical form, for example as a flowchart, a diagram, a graph, or a simple map showing directions. Or something is equivalently stated in graphical form, for example an image that is a graphical representation of text that does not appear in the surrounding text. In such cases, an image can be given using the img element, but the [note: omitting the word 'lesser' that appears in the current spec language] textual version must still be given, [etc, rest of current spec paragraph follows] -- Bill Mason Accessible Internet [EMAIL PROTECTED] http://accessibleinter.net/
Re: [whatwg] ALT and equivalent representation
On 18/04/2008, Bill Mason [EMAIL PROTECTED] wrote: The example was a case of a hacker who replaces the Google logo on google.com with an image only containing the text WE HACKED YOUR SERVERS. We assume the hacker cares enough about accessibility to set the alt attribute to the same text. More generally (and less hypothetically), this is any case where an image is being used just to display text (in a nicer font, or nicer colours, or animated and on fire, or some other reason it's worth using an image instead of plain HTML). Since the image is no longer the company logo, it falls outside the logo discussion in the Icons requirement for alt. I believe the company logo case is also unclear in the spec. See e.g. http://www.google.com/ (when it's not a special day) - the image is simply the word Google (as a page heading, so it should probably be in h1), so common sense says it should have alt=Google. The spec phrase Icons: a short phrase or label with an alternative graphical representation sounds like it might apply here, but none of the cases in that section seems to work: in particular, I don't think the logo is being used to represent the entity would apply, because the purpose of the image is not to represent the entity (as it would be in e.g. a list of search engines that shows small images of all their logos so you can choose your favourite), and instead its purpose is to tell users what site they are on (and to make it look prettier). It should be made clearer whether the existing case does or does not apply. If it does not apply, it should be made clear what alt text to use instead. Since we're on this topic... What should happen for 'tracker' images? (i.e. img src=http://evil.google.com/user-track.php?site=97519340; width=1 height=1 alt=???) As some examples, Geocities has alt=setstats, someone has alt=statystyka, someone has alt=CrawlTrack: free crawlers and spiders tracking script for webmaster- SEO script -script gratuit de détection des robots pour webmaster, etc, and those examples do not help users who are seeing the alt text. Such images are pretty common, and they're not going to go away, so we should minimise their harm by saying alt= is appropriate. None of the cases in the spec seem to cover this case yet. http://validator.nu/?doc=http%3A%2F%2Fwww.google.com%2Fshowimagereport=yesshowsource=yes shows that some versions of Google (depending on cookies, IP address, etc) implement the Google logo as four separate images, approximately like: .--.-.. | G o o|g|l e | '--+-+' '-' Suomi where the Suomi (text, not image) is adjacent to the g's descender. The Goo image has alt=Google, and the other three images have alt=. When the page is viewed without images, that means it will say Google instead of the logo, which is a good thing. But HTML5 says that the alt text is equivalent to the image, which is not true (and could only be satisfied by alt=Goo, alt=le, alt=Most of a g, alt=A little bit of a g, which would be silly) - in this case, it is the combination of alt texts on the whole page that is equivalent to the combination of images on the page. google.com is splitting the image up to fit it in a layout table, which is non-conforming HTML5; but there are other more legitimate reasons for having several img elements representing a single piece of text, and in those cases it seems sensible to put alt=all the text on one image and alt= on the others. Should HTML5 be changed to accept this? And as a more general point, the spec provides a list of cases for using img (and how to use alt for those cases), but this list will never be complete (especially since the case matches are all subjective and open to interpretation in multiple ways), so there needs to be a default case statement for images where the author doesn't think any of the specific requirements applies. -- Philip Taylor [EMAIL PROTECTED]
Re: [whatwg] ALT and equivalent representation
RE: Comments by Phillip Taylor and Bill Mason regarding alt= You both raise some excellent points. Logically alt should be optional since as you clearly demonstrate some things have no alternate textual meaning (at least not one of any value to the user). The trouble with alt= (or no alt) is the unfortunate but extremely common tendency for designers to simply ignore the small percentage of people that need alt tags to access the internet. Clients will generally shop around for a web company that offers the lowest prices to provide the flashiest designs. There's a tendency for the lowest bidder to take shortcuts that the client will never see, alt tags being one of these. To make matters worse some browsers display the alt tag while waiting for images to come from the server and this creates visual artifacts that designers and clients generally consider undesirable. The end result of this is that alt tags tend to be seen as a burden by the majority of web designers I've met. The ONLY reason they get used at all is because validators complain about them not being included and because SEO companies are trying to stuff more keywords into the page. I often spend a considerable amount of time inserting alt tags that other designers consider optional. It is a debatable point whether these tags are a personal whim or an essential part of the contract. Essentially without some guidance from the specification it is my client who pays for my charity to disadvantaged users. I know that in most cases blind users do not form a significant enough percentage of their clientele to affect profits (it may be a art gallery for example). Also these are not government sites or contractors with mandated accessibility, and as far as I know there is no law requiring corporate sites to provide alternative text for blind users. The ONLY business justification I have for using alt tags is that a w3c valid site REQUIRES them and this may increase the sites Google rank (which is just speculation really). If you take the requirement out to use them on every image in a valid site then you take away much of my argument for using them at all. I think this is a case where logic must give way to corporate consideration, as public and charitable sites would probably use alt tags without being told, but 95% of the mainstream internet will not - given half a chance. Shannon
