The “Break this
page!” experiment
Aaron Doust and I have been working on an experiment in access
to photographs contained in Web pages.
Background
There are three issues at stake:
- Not all browsers can display graphics. Lynx and WannaBe are text-only browsers, for
example.
- Some nondisabled netters surf the Web with graphics loading
turned off because it’s faster.
- Blind and visually-impaired people can’t see the graphics
or can’t see them well, and/or may also be using a text-only
browser or have graphics loading turned off.
Experimental pages
Four Web pages at Aaron’s
site have been developed to show how, in the real world, this
problem can be solved. We are bringing accessibility out of the
realm of the theoretical here.
First of all, every image on Aaron’s site (not just the
test pages in question) now has an alt text, which is required in HTML 4.0 and
has always been recommended in previous versions of HTML. A great
many Web authors fail to include the dead-simple feature of alt
texts, which by themselves make a site easier to use for people in
the three categories above.
There is, however, a new technique for making visually-complex
pages accessible to anyone who can’t see the graphics:
Writing descriptions of the images where alt texts are
insufficient. Typically the descriptions
are linked via a small but noticeable D. tag alongside
the image or in a navigation bar. The downside of this technique is
the visibility of the D. links – and, of course, the
difficulty of persuading Web-jockeys that the 30 seconds it takes
to write the description is even worth it in the first place.
The photos contained in these four subpages now have written
descriptions. (They’re Aaron’s photos and he wrote the
HTML; I wrote the descriptions.) The photos depict various biketrials
riders in Perth, Australia. Bicycle trials is
a discipline of cycling in which the aim is to ride over, across,
and through obstacles without putting your foot down. If the topic
isn’t of much interest to you, well, make allowances. The
point here is that even a hobbyist page can be accessible, and if
hobbyist pages can be, corporate Web sites easily can be
accessible, too.
There are four pages with four different approaches.
- Case 1 (Margaret River): These photos use a
novel approach of linking a text description to the actual caption
of the photo. You thus have three ways to interpret the photo
without graphics: From the alt text, from the written caption, and
from the long description that caption links to. This approach
works in, say, journalism sites where photos are given captions, as
was the convention in the print newspapers they often emulate. It
solves the problem of cluttering up pages with D.
links to descriptions. It introduces its own problem of cluttering
pages with two visible descriptions and one invisible description
all of the same thing.
- Case 2 (East Perth): Here, we adhere to the
HTML 4.0 standard for the
longdesc
tag for long descriptions.
- Case 3 (King’s Park): In this page, all
photos have descriptions, links to which are given by
(D). But all the descriptions are in one single file
with different <#anchor> links.
- Case 4 (Subiaco): All photos have descriptions,
links to which are given by (D). All descriptions
occupy their own separate files.
Further options
Other techniques we could have used, but did not, include
setting up a neighbouring single-pixel GIF the same height as the
image that is itself a link to the long description. This is an
unsatisfactory solution for various reasons. If you’re using
a graphical browser with graphics turned off, your font size is
quite unlikely to be small enough to display the (D)
or D. so that you can actually click the thing. If you
have graphics loading turned on, you never see the link, and might
notice it only if you catch the status line changing as you happen
to move the mouse over it. This technique tends to render you more
blind than you already are. Solely in text-only browsers does this
approach provide accessibility and elegance.
Further, we could have written nifty little lines of Javascript
that tell you to click the image for a full description when your
cursor hovers over the image. That wouldn’t work here (a)
because there’s no Javascript and (b) because selecting the
image brings up a full-size version of the photo. Still, it works
in two other sites, vallartabooks.com and tropicasa.com, which actually do a number
of good things for accessibility and are themselves models.
We did not write descriptions of the entire pages as a visual
whole, and all the images are presented within tables, which are
certainly not universally accessible.
The crunch
We sent out word of our experiment to relevant mailing lists.
The instructions:
What we want you to do is to break our pages.
Load the four subpages in every conceivable combination of
platform, browser, graphics mode, and assistive technology. The
more unlikely, the better. We especially want to hear from PDA
users (like Newtons or PalmPilots) and people using speech output.
Tell us how the pages look and how easy or difficult they are for
you to navigate and interpret. Every aspect is up for discussion,
from coding to appearance to writing. All suggestions articulated
in a reasonably good-natured tone will be considered, and we may
update the pages over time to try new things.
Selected responses:
-
From Petr Fuchs: If
you look at that picture page on high-res screen, (D)
tags interfere with the right border of table where picture is
placed. If you insert a <br> tag in front of the
(D) definition string it will always fall on the
bottom of the picture and be centered.
I viewed with graphics activated on another occasion, and the
wallpaper on the right side is distracting [and reduces]
readability of the text; get rid of it or make it light-coloured,
or use frames to move the text to the right of that wallpaper
column (as on my page). If
you intend to have your page more readable by people with low
vision, blast description text with big bold fonts without any
background (descriptions are shorter and could fit on-screen in a
bigger font since descriptions are a standalone page).
-
From Serge
Munhoven: First impression: I like Case 1 best so far.
Case 1: Suggestion – leave the picture inlined
on the caption page as well. After all, it is not that useful to be
told that the related file’s name is
derekbbqlog.jpg. But seeing the picture while reading
the caption.... Supposing that images are turned off anyway, or
that the picture is already in the browser’s cache, this
should not be a big bandwidth issue.
I was going to make a comment about Lynx’s options for
handling images with or without alt strings, but having had a
closer look at your source, I was wrong. Currently I get
either:
Derek Price hopping from the BBQ ring to a fallen
log.
= link to large image
or
Derek Price hopping from the BBQ ring to a fallen
log.-[IMAGE]
= link to large image
= link to small image
What I’d like:
Derek Price hopping from the BBQ ring to a fallen
log.-[INLINE]
= link to large image
= link to small image
but this is rather a limitation/design choice of Lynx. Must give
some more thought to what really does not please me. Just the
chosen word, perhaps?
Case 2: Ooops, true: no longdesc
available, but knowing people, Lynx may become the first browser to
support it :-) The regular repetition of "Big Picture" is a bit
disturbing.
Case 3: Here again you might miss the picture
when reading the description. Now, there would be definitely no
sense in putting them all on the description page this time.
Thumbnails, perhaps? That would leave you with three sizes of
pictures. Not ideal either. Though thumbnails with ALT="Back
to photos" could replace that link?
Case 4: Same comment as Case 1: include the picture? Are you displaying
the description in a separate browser window, though? In that case
it’s another issue. Anyway, one thing I don’t like
either is having my workspace filled up with browser windows.
Back to your pages: a comment concerning all of them is that the
small inlined captions on the main pages are closer to the
following image than to the related images (when rendered by Lynx,
at least). This is a bit confusing. Oh, yes: and avoid if at all
possible the phrase "Click on the image"/"Click here to...." On a
hardcopy, this becomes a bit surrealistic :-), but my main point is
that I don’t click. Perhaps "select" is more neutral (though
just as surrealistic, I agree).
-
From Philip
Webb:
Case 1: You need to mark the captions
"Caption:" since alt text and captions come out as links with
nothing to differentiate them.
Case 2: This is a mess. Each title is repeated
(underlined the second time), with a link called "Big Picture"
in-between each pair.
Case 3: This works quite well. Only one page to
download if you just want words; however, there’s still the
nuisance that each caption is repeated.
Case 4: This is less satisfactory. Each caption
appears twice (as in Case 2).
Brad and René sound like a right pair of nerds ...
(grin).
Browser issues
Browser support for longdesc
is poor but
improving.
- iCab, a perfectly usable,
compact, highly-standards-compliant Macintosh browser in seemingly
perpetual beta, supports
longdesc
, “but
it’s some[what] hidden,” says Alexander Clauss.
“Control-Click on the image and choose in the
contextual menu ’Image/description’ and iCab will open
a new window and display the description in it.”
- Mozilla,
the open-source browser, does indeed give you access to
longdesc
. Right-click or Control-click on
the image, and select Properties. A link to the description, if
any, is presented there.
- Netscape 6, based on Mozilla, should theoretically provide the
same kind of function, but I have not verified that yet.
- No variant of Netscape 4 or Internet Explorer supports
longdesc
. Neither does Opera or Lynx.
So just at the level of browser readiness, we have a problem.
longdesc
may not be ready for prime time.
Conclusions
We don’t think the four approaches can be vastly improved.
They all have pluses and minuses. In the future, we may use this
information to lobby the World Wide Web Consortium for
updated HTML specifications.