- From: Marti <marti47@MEDIAONE.NET>
- Date: Sat, 20 Nov 1999 09:26:22 -0500
- To: <bbailey@clark.net>, <w3c-wai-ig@w3.org>
- Cc: "GARETH P PARKINSON" <298gpp@tay.ac.uk>
Bruce, Thank you for the clear statements on this issue. From a personal standpoint I have frequently be annoyed by the use of alt="", I am always left wondering what the intent was and what I might be missing, on the other hand I don't really need to be told about every little 'spacer.gif', that too can be annoying. A system of punctuation marks to indicate the function of various graphics seems like a great solution but since we seem to have trouble getting people to use any alt= in many cases, it seems like a bit of a dream. > The difference between null and missing ALT text is the real life behaviors of > browsers. In somecases, MISSING alt text is PREFERABLE to null alt text! > > >From the User Agent Accessibility Guidelines (now in "last call" status) at > URL: > http://www.w3.org/TR/1999/WD-WAI-USERAGENT-19991105/#gl-content-access > <Q>2.8 When alternative text has been specified explicitly as empty (i.e., an > empty string), render nothing.</Q> > > This is how Lynx currently behaves, but not pwWebSpeak. The guidelines say > nothing about what to do about missing alt (and invalid html, of which would > be one example. Lynx (and the big two with image loading off) generate > something like [IMAGE]. This is different behavior than ALT=" " or > ALT="nbsp;". The bigger problem is when an image is a link. With Lynx, each > link normally gets a number, so the following snippets of code are shown next > to the default rendering with Lynx: > <A HREF="foobar.html"><IMG SRC="foobar.gif"></A> [1][LINK] > <A HREF="foobar.html"><IMG SRC="foobar.gif" ALT="Foobar"></A> [2]Foobar > <A HREF="foobar.html"><IMG SRC="foobar.gif" ALT=" "></A> [3] > <A HREF="foobar.html"><IMG SRC="foobar.gif" ALT=""></A> > > Notice that the last example generates nothing! If "hidden" links are the ONLY > links on a page, Lynx generates a warning, but otherwise these hidden links are > effectively invisible. (One can list all links on a page, or look at the > source code, but these are extreme time consuming measures.) > > We have been over this before, and many have made the arguement that ALT="" is > frequently appropriate. I agree that it should be valid html, but I think this > is a point where the WCAG could make a clear unabigious distinction. > > The problem with ALT="" is that it is ambiguous. You don't know WHY the author > put that in there. Is he just trying to get his code validated? Is this > REALLY just a decorative, content-free graphic? Does he have something against > text-based browsers? Is this some kind of spacer image? Did he just forget? > > IMHO, ALT="" is NEVER prefereable to other choices. > > For decorative graphics, use a single non-alphanumeric character. There is > ALWAYS a punctuation mark that is closer in meaning (closer than nothing > anyway) to a "content free" image. > > The burden of repeated links (one big arguement for using ALT="" within <A HREF > ... /A>) is much less of a problem than the chance of missing content and > links! > > Bruce Bailey > > > GARETH P PARKINSON wrote: > > > Hi Len, > > I was wondering what effect placing a null value in the alt tag. Doesn't > > this result in the same problem as having no alt tags at all, in that the > > user will be prevented from finding out the reason for the image? I would > > assume that in most cases the image has some meaning, and therefore would > > benefit the user if they could have a description of it. > > > > I don't doubt that on a very busy interface there might be call to reduce > > the amount of text (although perhaps the page is overloaded anyway?) , but > > such decisions should be made with a lot of caution, and only when there's > > no other way to simplify the page. Otherwise,it might wrongly encourage > > designers to use null values on images that would enhance the page. > > > > Gareth Parkinson > > > > -----Original Message----- > > From: Leonard R. Kasday <kasday@acm.org> > > To: Scott Luebking <phoenixl@netcom.com>; <w3c-wai-ig@w3.org> > > Date: 15 November 1999 16:09 > > Subject: Re: A few thoughts on using dynamic web pages to improve > > > > >Hi Scott, > > > > > >Thank for the extra example. I just want to check one thing to preempt any > > >misunderstanding. Even though you offer a page with alternate layout and > > >other changes to make browsing more efficient with screenreaders, you still > > >make the default page "accessible" in the conventional sense, right? > > > > > >For example, the default page would still satisfy the web accessibility > > >guidelines... alt text, table reading order, etc. It's just that the > > >alternate page would be more efficient to use. > > > > > >As for the details... > > > > > >1. It does seem useful to have an alternate layout where the section of > > >links and references come at the end instead of the beginning. It might > > >also be useful to have a link at the start of the page to jump to that > > section > > > > > >2. You speak of leaving out decorative images, but why not accomplish that > > >by simply having null alt text? A ha. >
Received on Saturday, 20 November 1999 09:49:42 UTC