E-mail List Archives
Number of posts in this thread: 18 (In chronological order)
From: Leo Smith
Date: Jun 4, 2004 6:05AM
Subject: An Accessible method of hiding HTML content
No previous message | Next message →
Hi Folks,
I just wanted to draw your attention to a really interesting article that
Paul Bohman has written, that is on the Webaim site:
An Accessible Method of Hiding HTML Content
http://www.webaim.org/techniques/articles/hiddentext
I have already been trying some the techniques he mentions.
I am having a little trouble with the technique for using Graphics as
Headers whilst concurrently having a text heading within proper semantic
markup. I don't seem to be able to get it to work, coding as the example
does in the article. I have found an alternative way that seems to work OK:
namely placing the heading element with the header text first (would be the
same text as the graphic as header), then the header graphic with null alt
text afterwards (outside of the heading element). Looks like this:
Current Designs
The heading element has the same class applied to it that Paul provides --
it places that content visually above the page view, but it is still
accessible to AT and to search engine crawlers.
I wonder if I am missing something with the original example (in the
article), which is why I can't get it to work. Any help would be
appreciated.
Thanks!
Leo.
From: Tim Beadle
Date: Jun 4, 2004 6:16AM
Subject: Re: An Accessible method of hiding HTML content
← Previous message | Next message →
On Fri, Jun 04, 2004 at 08:08:43AM -0400, leo wrote:
> I am having a little trouble with the technique for using Graphics as
> Headers whilst concurrently having a text heading within proper semantic
> markup. I don't seem to be able to get it to work, coding as the example
> does in the article. I have found an alternative way that seems to work OK:
> namely placing the heading element with the header text first (would be the
> same text as the graphic as header), then the header graphic with null alt
> text afterwards (outside of the heading element). Looks like this:
>
> Current Designs
>
You may be interested in the work that has been done in the past year or so
wrt CSS image-replacement techniques.
All you would need then would be:
Current Designs
Then in your style sheet:
#current {
/* The requisite CSS, depending on the replacement method used */
}
For more info, see here:
http://www.mezzoblue.com/archives/2003/12/12/accessible_i/
Tim
--
"Email is a wonderful thing for people whose role in life is to be on top
of things. But not for me; my role is to be on the bottom of things."
-- Donald Knuth
From: Victoria Hamill
Date: Jun 4, 2004 6:51AM
Subject: Re: An Accessible method of hiding HTML content
← Previous message | Next message →
This article is very interesting, and offers some great ideas - I've passed
it on to each of our developers to learn from it.
However, the reason I fight our designers whenever they want to use images
for titles or other textual elements is that if a short-sighted user is
enlarging the text on the screen, these obviously can't be enlarged.
I thought that this was at least as significant a problem as the semantic
accuracy of the page, as accessibility is not just about screen readers,
and so I generally rule them out completely - unless they are pretty big
text to begin with, which form labels etc. don't tend to be. As no-one else
has made a comment along these lines, I'm wondering if I'm missing
something??
Victoria
From: Tim Beadle
Date: Jun 4, 2004 7:04AM
Subject: Re: An Accessible method of hiding HTML content
← Previous message | Next message →
On Fri, Jun 04, 2004 at 01:54:35PM +0100, victoria.hamill wrote:
> This article is very interesting, and offers some great ideas - I've passed
> it on to each of our developers to learn from it.
>
> However, the reason I fight our designers whenever they want to use images
> for titles or other textual elements is that if a short-sighted user is
> enlarging the text on the screen, these obviously can't be enlarged.
>
> I thought that this was at least as significant a problem as the semantic
> accuracy of the page, as accessibility is not just about screen readers,
> and so I generally rule them out completely - unless they are pretty big
> text to begin with, which form labels etc. don't tend to be. As no-one else
> has made a comment along these lines, I'm wondering if I'm missing
> something??
I don't know for sure, but I think I heard that the ability to resize text
using browser controls, and the avoidance of text-as-images, is a bit of a
red herring because people who are hard of sight would be more likely to use
screen magnification software, which zooms in on the page like a magnifying
glass. Thus text set in pixels (in IE) and text-as-images would be enlarged as
well.
Feel free to correct me, however!
Tim
--
"Internet Explorer is like a box of chocolates. You never know what you're
gonna get." -- Sjors
From: Sandy Clark
Date: Jun 4, 2004 7:10AM
Subject: Re: An Accessible method of hiding HTML content
← Previous message | Next message →
The problem is that most graphics shown on HTML pages are bitmapped which
means they don't magnify very well. Vector Graphics scale well (such as
those used with Flash).
From: Chris Heilmann
Date: Jun 4, 2004 7:11AM
Subject: Re: An Accessible method of hiding HTML content
← Previous message | Next message →
>
> On Fri, Jun 04, 2004 at 01:54:35PM +0100, victoria.hamill wrote:
>> This article is very interesting, and offers some great ideas - I've
>> passed
>> it on to each of our developers to learn from it.
>>
>> However, the reason I fight our designers whenever they want to use
>> images
>> for titles or other textual elements is that if a short-sighted user is
>> enlarging the text on the screen, these obviously can't be enlarged.
>>
>> I thought that this was at least as significant a problem as the
>> semantic
>> accuracy of the page, as accessibility is not just about screen readers,
>> and so I generally rule them out completely - unless they are pretty big
>> text to begin with, which form labels etc. don't tend to be. As no-one
>> else
>> has made a comment along these lines, I'm wondering if I'm missing
>> something??
>
> I don't know for sure, but I think I heard that the ability to resize text
> using browser controls, and the avoidance of text-as-images, is a bit of a
> red herring because people who are hard of sight would be more likely to
> use
> screen magnification software, which zooms in on the page like a
> magnifying
> glass. Thus text set in pixels (in IE) and text-as-images would be
> enlarged as
> well.
>
> Feel free to correct me, however!
Yes, and Opera also Zooms the whole lot.
However, there are people which have bad eyesight but don't use all of
them, too. So, to be on the safe side, it is better not to use images as
headlines, or give the option to turn that off via a server control.
--
Chris Heilmann
The mighty pen: http://icant.co.uk/
Learn to let go! http://ltlg.icant.co.uk
Binaries: http://www.onlinetools.org/
From: Tim Beadle
Date: Jun 4, 2004 7:17AM
Subject: Re: An Accessible method of hiding HTML content
← Previous message | Next message →
On Fri, Jun 04, 2004 at 09:12:25AM -0400, sllists wrote:
> The problem is that most graphics shown on HTML pages are bitmapped which
> means they don't magnify very well. Vector Graphics scale well (such as
> those used with Flash).
Very true - I should have pointed this out. My main point still holds, though.
For users of magification software, otherwise unresizable text will resize,
albeit with 'jaggies' in the case of bitmapped graphics.
Tim
--
"Those confused souls who write *virii are tacitly positing the existence of
the non-word *virius, and declining it as though it were like filius...Virii
is still completely silly, so don't do that; otherwise, everyone will know
you're just a blathering script kiddie." -- Tom Christiansen
From: julian.rickards
Date: Jun 4, 2004 7:43AM
Subject: Re: An Accessible method of hiding HTML content
← Previous message | Next message →
I must admit that although I am pleased to learn of a technique that enables
a designer to hide items without making them inaccessible, I question the
example Paul gave in his article in which he uses a form to allow data entry
for two teams at the same time. Perhaps, this is why this hiding technique
is required, to accomodate a format that would be difficult for screen
reader users to use. Personally, I would have broken the form into two, one
for each team, and then much (if not all) of the need to hide certain
content would be eliminated.
What does this say about the use of this technique? Well, it works -- that
much is clear from one of the references at the bottom where testing was
performed -- and that is a good thing. However, it is my feeling that there
are few situations in which it may be of benefit (given that I have
eliminated the above table example). One example was to hide the skipnav
link because it detracts from the design. I appreciate the design issue but,
as a contributor to a gov't web site, it is my opinion that not only should
we make our web site accessible, we should make it clear to everyone that we
have attempted to do so, and not just by inserting a link to an
accessibility statement. Therefore, I would not hide the skipnav link.
Additionally, what about those persons who can see but use keyboards instead
of mouses (mice?): I was told once that they benefit from visible skipnav
links so hiding it from them prevents them from using it or if they tab and
hit this link, how do they know what it is for if they can't see it?
Finally, I have a question about tab order that I can't answer but Jim
Thatcher has done some significant research in this area. If a link is
hidden, can we be certain that tabbing in all browsers will find it?
Personally, I don't like the thought of using CSS to "destroy" (not meant as
a reference to Moose's CSS Destroy articles) content except in specific
situations such as a print stylesheet where web-only items (such as
navigation bars) make no sense on paper.
Jules
---------------------------------------------------------
Julian Rickards
Digital Publications Distribution Coordinator
Publications Services Section
Ontario Ministry of Northern Development and Mines
Phone: (705) 670-5608
Fax: (705) 670-5690
From: Tim Beadle
Date: Jun 4, 2004 7:57AM
Subject: Re: An Accessible method of hiding HTML content
← Previous message | Next message →
On Fri, Jun 04, 2004 at 09:45:41AM -0400, julian.rickards wrote:
> Personally, I don't like the thought of using CSS to "destroy" (not meant as
> a reference to Moose's CSS Destroy articles) content except in specific
> situations such as a print stylesheet where web-only items (such as
> navigation bars) make no sense on paper.
Joe Clark wrote about the problems with the now-deprecated Farhner Image
Replacement technique [1], which wasn't accessible because it used
display: none to hide content. This hid it from screen readers as well,
unfortunately.
Paul's technique doesn't use display: none, but rather moves the content off
the page, so remains accessible.
Tim
[1] http://www.alistapart.com/articles/fir/
--
"That's a whole lotta transparent GIFs going to be waiting in line at the job
centre." -- Nathan Pitman
From: Mark Magennis
Date: Jun 4, 2004 9:45AM
Subject: Re: An Accessible method of hiding HTML content
← Previous message | Next message →
> people who are hard of sight would be
> more likely to use
> screen magnification software,
My experience is that most people with low vision do not use magnification
software but instead use one or more of the following three methods:
1. Squint.
2. Press your nose against the screen.
3. Give up.
Using methods 1 and 2 is not ideal and, in practice, many people with low
vision simply do not manage to read a lot of stuff successfully or they take
a very long time over it. They may put up with getting the gist but missing
some of the details. The reasons many people don't use magnification
software are:
1. It is not provided on the machine they use (by school, employer, library
staff, etc.).
2. They would have to buy it to use on their home machine.
3. You have to learn to use it.
4. It doesn't exactly make reading a document or web page very easy since
you are, essentially, reading through a cut-out that you have to move
around. In fact, it's usually a pretty awful experience.
My personal opinion is that unresizable content is a much more serious web
accessibility problem than it is generally taken to be. I think it affects a
lot more people than is often recognised. There is a huge emphasis on
blindness but very little on low vision which is statistically far more
prevalent, despite being often undiagnosed or even not admitted. I myself
have 20:20 vision but in June and July my hay fever gets so bad that I have
to wear sunglasses while working at my computer. That makes it difficult to
see the screen, so I bump up the text size using my wheelie mouse.
Occasionally when it is really bad I have to switch to light blue text on
black or yellow on dark blue (it varies which one is easier). Today is not
so bad so I'm not wearing my glasses and I've only bumped up the text one
notch. But I rely on being able to do this, otherwise it is very difficult
to read things. And my vision is classed as 100 percent. Low vision is one
of those things like poor literacy where the extent of the problem is just
not recognised because it is difficult to notice. Did you know that 20 -25%
of adults in Ireland, UK, USA, France, etc. are functionally illiterate
(OECD figures). Most people are seriously shocked by this statistic. After
all, you never seem to see them do you. Same with low vision I think.
Mark
Dr. Mark Magennis
Centre for Inclusive Technology
National Council for the Blind of Ireland
Whitworth Road, Dublin 9, Republic of Ireland
= EMAIL ADDRESS REMOVED = tel: +353 (0)71 914 7464
From: Paul Bohman
Date: Jun 4, 2004 10:11AM
Subject: Re: An Accessible method of hiding HTML content
← Previous message | Next message →
I'm glad to see that there are some comments on this list about my
article about hiding content
(http://www.webaim.org/techniques/articles/hiddentext). When I wrote
that article, I did so knowing that the very concept of hiding content
is a controversial one.
The technique works. The questions now are these:
- should it be used?
- if so, where, and under what circumstances?
1. Should it be used?
I'm not going to pretend that this technique should be used everywhere.
I won't even claim that all of the examples in my article represent
ideal situations in which to use the technique. They are merely ideas
and possibilities.
The technique itself was born out of necessity. There are Web designers
out there who are true designers. They are artists, and, being an artist
myself, I understand their perspective. Attractive visual designs are
not superfluous. They have the potential to increase user enjoyment,
site usability, and content comprehension. These are not trivial
matters. Visual design is important, just as accessibility is important.
They are not mutually exclusive. In fact, they are complimentary.
On the other hand, there are some rare circumstances in which visual
design seems to be at odds with accessibility. Rather than deny artists
their creative freedom, why not try to solve the problem in a way that
is productive from both an accessibility standpoint and an artistic
standpoint?
So my answer to the question of whether or not it should be used, is
"yes, when necessary." That, of course, brings us to the next question:
2. Where and under what circumstances should this technique be used?
After writing the article, a reader pointed out that using background
images for necessary text (such as headings) using the technique I
describe in the article is accessible to screen reader users, but not
necessarily to all users with low vision. Some users with low vision
change the background colors without overriding the entire style sheet.
If they override the entire style sheet, then there is no problem,
because the text will display properly, in the correct location.
However, if they turn off only the background styles, then the text
remains hidden and the background image also disappears. This creates an
instance of a missing heading.
This is an example of a situation in which my technique is less than
ideal. I could try to defend the technique by saying that it's an issue
that browsers can solve, which is partly true, but I have to admit that
it is still a problem here in the real world. I'll probably put some
comments in the article that discuss this potential problem.
On the other hand, there are some situations in which I think the
technique can be used beneficially. I personally use the technique to
"Provide Contextual Cues Just for Screen Reader Users" as discussed in
the article. There are situations in which the visual design
communicates a sense of organization and structure which simply cannot
be conveyed in the simplistic structural tags of HTML, no matter how
hard we try. Heading tags, bulleted lists, and so on do not have the
same organizational power as cleverly designed visual interfaces with
visual groupings and other visual elements. There is just no comparison.
To make up for this deficiency, it can be beneficial to add little bits
of text that explain some of these organizational elements to screen
reader users. You can say such things as "begin sub-menu", "end
sub-menu", "begin main content", or whatever. Sighted users don't need
this information, because they already have this information.
In a sense, you are providing a "text alternative" to the visual
organization of the page. Think about that concept for just a moment.
Think about how much information and orientation cues are lost on
complex sites when you can't see them. Why not provide a text
alternative for this information? The concept of text alternatives is
not limited to images alone. The concept applies to *anything* that is
not represented in text. Not all of these elements are important or
useful, but if they are, wouldn't you want to convey this information to
all users?
Not every site design needs these bits of text, but complex sites can
definitely be made more usable by helping screen reader users orient
themselves a little better.
Can this technique be over-used and abused? Of course. Any technique
can. Just make sure that *you* are not the one abusing it!
--
Paul Bohman
Project Coordinator
WebAIM (Web Accessibility in Mind)
www.webaim.org
Utah State University
www.usu.edu
Web Accessibility Coordination & Leadership Online Training
Starts June 1, 2004
Sign up now at http://www.webaim.org/events/symposium/
From: Tomas Caspers
Date: Jun 5, 2004 5:55AM
Subject: Re: An Accessible method of hiding HTML content
← Previous message | Next message →
Also sprach tsb:
> Paul's technique doesn't use display: none, but rather moves the
> content off the page, so remains accessible.
Sorry, but no, it's not. It may be accessible to some screenreaders, but
since it still uses a CSS background image it remains inaccessible to
folks who need a different color scheme. IE does not display background
images as soon as you invert your colours or select one of the
pre-defined schemes (contrast#1 and the likes). If the information
conveyed in the image is critical for the understanding or even just for
spatial orientation, this page remains inaccessible for certain users.
/Tomas
--
This space intentionally left blank
From: Paul Bohman
Date: Jun 5, 2004 7:58AM
Subject: Re: An Accessible method of hiding HTML content
← Previous message | Next message →
tomas wrote:
>
>> Paul's technique doesn't use display: none, but rather moves the
>> content off the page, so remains accessible.
>
>
> Sorry, but no, it's not. It may be accessible to some screenreaders,
> but since it still uses a CSS background image it remains
> inaccessible to folks who need a different color scheme.
Right. That's essentially what I said in my last post. The technique of
hiding text content from sighted users is best applied to situations in
which the visual context is not represented in a text form. Under these
circumstances, then, you can provide a "text alternative" to visual
contextual information, such as the beginning and ending of sub-sections
of a Web page. The technique then adds a text-based method of discerning
information that was already present for visual users, but which is
invisible to blind users.
In the case of background images, I have already stated (in agreement
with you) that my technique works for screen reader users, but not for
users with low vision who reset their background colors.
I think the real value of the technique is in helping screen reader
users orient themselves. Screen reader users navigate the Web more
slowly. Part of this slowness is due to the fact that they have to
listen to Web content in a mostly linear fashion. Another part of this
slowness is due to the mental concentration required to create a mental
map of the page. It can be difficult to distinguish one section of the
page from another, especially in complex pages.
Sighted users usually do not have much difficulty distinguishing
sub-sections of pages. These sub-sections are usually distinguished by
visual cues of some form or another. For example, the background color
may be different, or the content may be off to the right or off to the
left of the main content. The sub-section may have a different font. It
may have bold text. It may be enclosed in a layout table.
Any of these visual elements can provide a visual "map" of the page for
sighted users. Blind users cannot access this visual information.
By providing hidden text of some sort (whether using this technique or
another), blind users can be given the same sort of contextual
orientation that sighted users already have.
All it takes is for a small bit of text to say "begin main content" or
"end of the 'contact us' sub-menu."
And yes, this technique must be used carefully and judiciously. Not
every site needs to use it. The technique can be a burden to screen
reader users if over-used. It can be confusing if used poorly.
However, it can be useful when used well.
I'll be updating my article to reflect the comments on this list as soon
as this thread exhausts itself.
--
Paul Bohman
Project Coordinator
WebAIM (Web Accessibility in Mind)
www.webaim.org
Utah State University
www.usu.edu
Web Accessibility Coordination & Leadership Online Training
Starts June 1, 2004
Sign up now at http://www.webaim.org/events/symposium/
From: Derek Featherstone
Date: Jun 5, 2004 12:52PM
Subject: Re: An Accessible method of hiding HTML content
← Previous message | Next message →
paulb wrote:
> Some users with low vision change the background colors without
> overriding the entire style sheet. If they override the entire
> style sheet, then there is no problem, because the text will
> display properly, in the correct location. However, if they
> turn off only the background styles, then the text remains hidden
> and the background image also disappears. This creates
> an instance of a missing heading.
This point is really at the crux of the issue. We regularly teach developers
that when they are building their CSS rules that they ensure they declare
backgrounds (either images, or colours) with an appropriate foreground so
that if images are off, or stylesheets are off, or in some other situation,
there is appropriate contrast between foreground and background. The W3C's
CSS Validator even flags this issue as a warning.
My questions then are:
1. What mechanisms are these low vision users using to override the styles?
Browser settings? User Style Sheets? Other?
2. Where are they learning how to do so? On their own? From tutors? From
online resources?
3. Can we realistically expect the users or those teaching them to override
styles to do so in a way to ensure that both foreground and background are
overridden so there is no conflict as you suggest?
I'd like to think that if someone has figured out on their own to override a
background colour, then it is reasonable that they would also have the
ability to override the foreground colour. I'd also like to think that
anyone producing training materials would be able to express the importance
of overriding both foreground and background settings.
Your thoughts?
Best regards,
Derek.
--
Derek Featherstone = EMAIL ADDRESS REMOVED =
phone: 613.599.9784; toll-free: 1.866.932.4878 (North America)
Web Accessibility Specialist / Co-founder of WATS.ca
Web Accessibility Testing and Services http://www.wats.ca
From: Paul Bohman
Date: Jun 5, 2004 1:54PM
Subject: Re: An Accessible method of hiding HTML content
← Previous message | Next message →
Derek wrote:
>
> This point is really at the crux of the issue. We regularly teach developers
> that when they are building their CSS rules that they ensure they declare
> backgrounds (either images, or colours) with an appropriate foreground so
> that if images are off, or stylesheets are off, or in some other situation,
> there is appropriate contrast between foreground and background. The W3C's
> CSS Validator even flags this issue as a warning.
My response:
What you have described is good advice in a general sense. However, when
users are granted the ability to change the color of both text and
background, the end result is that you, the designer, have no control
over what your Web page is going to look like. Users with low vision
frequently set dark background colors and light text colors, which,
despite all of your careful planning, make graphics and other parts of
the page difficult to discern, especially if your Web page did not have
a dark background to begin with. Users can even set orange text against
a yellow background if they want to, though I doubt anyone would do this
for accessibility reasons.
Rather than lament this lack of control, it must simply be accepted, and
in many ways embraced. User freedom and personalization is an important
concept in the accessibility world that people with disabilities have
been crying out for. They now have this freedom (or at least large parts
of this freedom--there is still room for growth here), and it should be
respected.
Users can turn off images, they can change the font style, they can
linearize text, they can apply their own style sheets, they can convert
it into other formats... In short, they can "ruin" your design in every
way imaginable.
Derek asked:
> 1. What mechanisms are these low vision users using to override the styles?
> Browser settings? User Style Sheets? Other?
My response:
The most common and easiest method is to go into the settings of the
browser and override the color settings for text and background. You can
do this in IE, Netscape, Opera, and others. Every browser does this
somewhat differently, but most turn off background images in addition to
the background colors.
There are more sophisticated methods. You can design your own
stylesheet, or download them, but I doubt many users actually do
this--even among those with disabilities.
The implication is that nothing of importance should go in background
images.
Derek also asked:
> 2. Where are they learning how to do so? On their own? From tutors? From
> online resources?
My response:
I don't know the full answer to this question, but I do know that some
assistive technologies, including some screen readers and screen
enlargers allow users to change the background settings quite easily.
Another question by Derek:
> 3. Can we realistically expect the users or those teaching them to override
> styles to do so in a way to ensure that both foreground and background are
> overridden so there is no conflict as you suggest?
My response:
Sort of. You can tell people to create both a custom background color
and text color that are accessible in contrast to one another. Most
people do this already, and don't really need to be told to do it.
That's not really the problem. The problem is that the browsers allow
users to easily override *parts* of the author's style sheet, but the
browser doesn't tell you that that's what's happening. It just asks you,
for example, if you want to specify a certain background color and text
color.
That's a good option to have, but it's an incomplete set of options. In
many cases, just overriding the font and background color produces
results that are not optimally accessible, partly due to the fact that
these settings also get rid of background images.
What can authors do about this? Not much. The user is making the
decision to change the page styles, and the browser is allowing this
change.
In many cases, the best option for people who need custom styles is to
turn off the *entire* style sheet and replace it with their own (e.g.
black background, yellow enlarged text). Because this gives them *all*
of the text and images, and there is no question that they are getting
all of the content.
Unfortunately, it's not quite that simple for all circumstances. If the
style sheets provide visual contextual, orientation or organization
cues, then these cues will be lost (as I've explained before), so on
some Web pages, users are better off retaining parts of the style sheet,
such as positioning, even when colors are changed.
Those of us who train people with disabilities in using the Web ought to
inform them that there is a good chance that they will miss out on some
visual aspects of the page if they change the font and/or background
settings. That's an unfortunate fact of life, because too much of the
Web content out there depends at least partly on visual communication.
However, from the point of view of developers, we can try to ensure that
all aspects of "visual communication" in our Web content are conveyed to
users who don't have access to this visual information. When users turn
off only parts of our style sheets, that can be tricky, especially in
the context of low vision users. I admit that I don't have all of the
answers in this area in terms of low vision. Blind users are a bit
easier to accommodate in this context. By providing text-based cues (as
explained in previous posts), we can help blind users orient themselves
within the page and we can compensate for their inability to see visual
cues.
I know this is a bit of a convoluted explanation, but I hope it makes
some sense.
MY CONCLUSION (at least for now):
We, as developers, can provide cues to blind users that compensate for a
lack of visual ability. In the case of low vision users, however, their
ability to change background colors and foreground colors (and other
settings) can make content either more or less accessible to them,
depending on the settings chosen and on the nature of the content being
altered. I don't think there is a formula that works for all users or
for all Web content.
BUT, if developers create semantically correct Web sites that are truly
accessible to the blind, then people with low vision can turn off ALL of
the styles and the content will likewise be accessible to them, in the
same way that it is accessible to blind users.
--
Paul Bohman
Project Coordinator
WebAIM (Web Accessibility in Mind)
www.webaim.org
Utah State University
www.usu.edu
Web Accessibility Coordination & Leadership Online Training
Starts June 1, 2004
Sign up now at http://www.webaim.org/events/symposium/
From: Derek Featherstone
Date: Jun 5, 2004 8:35PM
Subject: Re: An Accessible method of hiding HTML content
← Previous message | Next message →
Paul,
I think I might need to reframe my last questions to you, as I think my
questions weren't clear enough. You answered questions I didn't really ask!!
Let me try again. You wrote in your message that a reader of your article
pointed out that "that using background images for necessary text (such as
headings) using the technique I describe in the article is accessible to
screen reader users, but not necessarily to all users with low vision." You
continued to write that this was because:
"Some users with low vision change the background colors without overriding
the entire style sheet.
If they override the entire style sheet, then there is no problem, because
the text will display properly, in the correct location. However, if they
turn off only the background styles, then the text remains hidden and the
background image also disappears. This creates an instance of a missing
heading."
If a user is turning off only the background styles, but not changing the
foreground styles, or completely overriding the stylesheet, isn't it the
user that is causing the problem? Why are they turning off only the
background styles??
This is where I drew the parallel to what I teach developers to do -- ALWAYS
ensure whenever they change a style, they change both the foreground and the
background. Why can't we expect users that are overriding background styles
(as you described in your paragraph) to also override the foreground as
well?
If they are changing backgrounds and not foregrounds, are they doing so
because the technology they are using doesn't let them? Or are they doing so
because they don't know how?
I don't understand the point that the reader was trying to make. If a user
overrides only part of a stylesheet to change just background but not
foreground, they need to make some adjustments in their techniques. And
anyone that is teaching people how to override styles like this owes it to
the person they are teaching to teach them to override both foreground and
backgrounds together rather than just backgrounds.
Does that make more sense, Paul? I really want to know why they are only
overriding background styles. Looking forward to your response...
Best regards,
Derek.
--
Derek Featherstone = EMAIL ADDRESS REMOVED =
phone: 613.599.9784; toll-free: 1.866.932.4878 (North America)
Web Accessibility Specialist / Co-founder of WATS.ca
Web Accessibility Testing and Services http://www.wats.ca
From: Larry G. Hull
Date: Jun 7, 2004 6:57AM
Subject: Re: An Accessible method of hiding HTML content
← Previous message | Next message →
At 9:58 AM -0400 6/5/04, paulb wrote:
>The technique of hiding text content from sighted users is best
>applied to situations in which the visual context is not represented
>in a text form. Under these circumstances, then, you can provide a
>"text alternative" to visual contextual information, such as the
>beginning and ending of sub-sections of a Web page. The technique
>then adds a text-based method of discerning information that was
>already present for visual users, but which is invisible to blind
>users.
>
>
>
>Sighted users usually do not have much difficulty distinguishing
>sub-sections of pages. These sub-sections are usually distinguished
>by visual cues of some form or another. For example, the background
>color may be different, or the content may be off to the right or
>off to the left of the main content. The sub-section may have a
>different font. It may have bold text. It may be enclosed in a
>layout table.
>
>Any of these visual elements can provide a visual "map" of the page
>for sighted users. Blind users cannot access this visual information.
Reading these comments, I was reminded of the increasingly popular
portals which are essentially a very large number of links arranged
into sub-sections that are distinguished by visual cues, often
lacking any text alternatives.
While the technique adds a text-based method of discerning
information that is already present for visual users but is invisible
to blind users, it doesn't seem to directly address the related
problem of finding a sub-section of interest. Perhaps I missed
something?
Sighted users can quickly scan the visual cues to find a sub-section
of interest. Blind users listening to the content in liner fashion,
even with equivalent text for the visual clues, may well give up on a
portal before finding a sub-section of interest due to a number of
sub-sections and a large number of links within each section. For
example, one portal I looked at recently had a sub-section that
provided weather information. To get there in linear fashion, one has
to listen to more than 150 links and any associated text identifying
sub-section visual clues (and this specific portal had no equivalent
text only images for each sub-section.)
I'm open to suggestions on how best to provide screen reader users
with a way to navigate the page similar to scanning the visual clues.
A visually invisible index comes to mind but perhaps there is a
better way?
Larry
From: Derek Featherstone
Date: Jun 7, 2004 7:43AM
Subject: Re: An Accessible method of hiding HTML content
← Previous message | No next message
larry.g.hull wrote:
> I'm open to suggestions on how best to provide screen reader users
> with a way to navigate the page similar to scanning the visual clues.
> A visually invisible index comes to mind but perhaps there is a
> better way?
I'd suggest the most obvious, and practical would be to ensure at a bare
minimum that a page such as you describe with multiple "sections" have
appropriate heading level markup. They could be visually styled to "fit"
with the rest of the design, and provide valuable information to screen
reader users, that can navigate from heading to heading (as an example, JAWS
users can navigate from heading to heading by pressing the "H" key).
That would provide a very basic level of allowing a screen reader user to
scan the page as long as the links were grouped with appropriate headings...
Best regards,
Derek.
--
Derek Featherstone = EMAIL ADDRESS REMOVED =
phone: 613.599.9784; toll-free: 1.866.932.4878 (North America)
Web Accessibility Specialist / Co-founder of WATS.ca
Web Accessibility Testing and Services http://www.wats.ca