Accessibility of star maps

[Safalra]

I'm planning to put some star maps on my website. Each constellation
(above about 40 degrees south) will have a page, starting with a star
map and followed by details of the mjor objects. I'm thinking of making
the star map an image map so visitors can jump down the page to the
appropriate star/nebula.

WAI recommends having extra text links for each link in an image map,
but is there much point in doing that here? Users without images would
be able to skip through a number of <h2>s as quickly as a list of
links, and the purpose of the image map here is that you click on what
you can see in the sky.

Also, should the alt-text of the star map be blank (''), or should I
make some effort to describe the general shape of the constellation
('Lyra is shaped like a kite, with Vega as its tail...')?

--
Safalra (Stephen Morley)
http://www.safalra.com/science/astronomy/

[Andy Dingley]

On 11 May 2005 03:10:35 -0700, "Safalra" <us****@safalra.com> wrote:

WAI recommends having extra text links for each link in an image map,

If that is sensible. Providing a non-graphic based alternative to the
whole thing is often better.

Assume a "star map" which links to information about particular stars,
where this "information" is itself a whole page and fairly detailed,
Duplicate this list somewhere (on another page) as a simple
text-navigable menu, and link clearly from the graphic page to the menu
page.

--
Cats have nine lives, which is why they rarely post to Usenet.

[Safalra]

Andy Dingley wrote:

On 11 May 2005 03:10:35 -0700, "Safalra" <us****@safalra.com> wrote:

WAI recommends having extra text links for each link in an image

map,
If that is sensible. Providing a non-graphic based alternative to the whole thing is often better.
Assume a "star map" which links to information about particular stars, where this "information" is itself a whole page and fairly detailed,
Duplicate this list somewhere (on another page) as a simple
text-navigable menu, and link clearly from the graphic page to the menu page.

Will this do?

http://www.safalra.com/astronomy/starmaps/lyra/

(I have uploaded all the index pages yet, so I know about those dead
links...)

--
Safalra (Stephen Morley)
http://www.safalra.com/hypertext/

[Mark Tranchant]

Safalra wrote:

I'm planning to put some star maps on my website. [...] WAI recommends having extra text links for each link in an image map,
but is there much point in doing that here? [...]

Also, should the alt-text of the star map be blank (''), or should I
make some effort to describe the general shape of the constellation
('Lyra is shaped like a kite, with Vega as its tail...')?

Are there any blind astronomers? I'm as keen as the next person to
provide accessible information, but it seems to me that you would be
adding work for zero benefit to anyone.

--
Mark.
http://tranchant.plus.com/

[Chris Morris]

Mark Tranchant <ma**@tranchant.plus.com> writes:

Safalra wrote:

I'm planning to put some star maps on my website. [...]

WAI recommends having extra text links for each link in an image map,
but is there much point in doing that here? [...]
Also, should the alt-text of the star map be blank (''), or should I
make some effort to describe the general shape of the constellation
('Lyra is shaped like a kite, with Vega as its tail...')?

Are there any blind astronomers? I'm as keen as the next person to
provide accessible information, but it seems to me that you would be
adding work for zero benefit to anyone.

Well, alt-text also has benefits for people using Lynx, etc.

If I didn't want to lose night vision while observing, then listening
to the page rather than looking at it would be a good idea.

--
Chris

[Andy Dingley]

On Tue, 17 May 2005 08:43:35 +0100, Mark Tranchant
<ma**@tranchant.plus.com> wrote:

Are there any blind astronomers?

As a general web-usability issue, this doesn't matter. Even if "blind
drivers" are an obviously self-limiting group, we must also think about
those with an _interest_ in <subject>, even though they've later
developed a disability that limits their web use. Do it for the blind
ex-astronomers, if you need a reason.

As a general software design issue, then never assume the non-existence
of unicorns. As Karl Popper pointed out so clearly, seeing one unicorn
proves that they exist, but no matter how many turn out to be horses
wearing party hats, that will never disprove the existence of anopther
real unicorn that you haven't seen. Users (and their bots) are creative
- they'll come up with ideas for things you never imagined at the
beginning. When you build a system you should permit anything that's not
actively forbidden - there's no way to tell how it might come in useful
in the future. Practical experience also tells us that a usefully large
fraction of this support does turn out to be unexpectedly later on.
re. the original site, then yes that's the sort of alternative nav that
I think works well. There don't seem to be too many links per map to
make this unwieldy (if there were, then I'd split that nav list onto a
separate page and link to it). If you look at the print stylesheet, you
can even make this "nav" feature into a useful index list if the page is
printed.

Once you've naved though, it seems to be hard to move back to the
constellation map - the breadcrumbs don't work, because we've jumped
onto a parallel branch.

--
Cats have nine lives, which is why they rarely post to Usenet.

[Safalra]

Andy Dingley wrote:

re. the original site,
For those that missed that post:

http://www.safalra.com/astrono*my/starmaps/lyra/
then yes that's the sort of alternative nav that
I think works well. There don't seem to be too many links per map to
make this unwieldy (if there were, then I'd split that nav list onto a separate page and link to it). If you look at the print stylesheet, you can even make this "nav" feature into a useful index list if the page is printed.
I hadn't thought of that. Aren't stylesheets just great? :)
Once you've naved though, it seems to be hard to move back to the
constellation map - the breadcrumbs don't work, because we've jumped
onto a parallel branch.

Hmm... I guess I could make the constellation name in the star name
into a link to the star map.

--
Safalra (Stephen Morley)
http://www.safalra.com/hypertext/

[Safalra]

Mark Tranchant wrote:

Safalra wrote:

I'm planning to put some star maps on my website. [...]

WAI recommends having extra text links for each link in an image map, but is there much point in doing that here? [...]

Also, should the alt-text of the star map be blank (''), or should I make some effort to describe the general shape of the constellation
('Lyra is shaped like a kite, with Vega as its tail...')?

Are there any blind astronomers?

See:

http://www.nfb.org/fr/fr9/fr03co23.htm

--
Safalra (Stephen Morley)
http://www.safalra.com/hypertext/

[Gérard Talbot]

Mark Tranchant a écrit :

Safalra wrote:

I'm planning to put some star maps on my website. [...]

WAI recommends having extra text links for each link in an image map,
but is there much point in doing that here? [...]

Also, should the alt-text of the star map be blank (''), or should I
make some effort to describe the general shape of the constellation
('Lyra is shaped like a kite, with Vega as its tail...')?

Are there any blind astronomers? I'm as keen as the next person to
provide accessible information, but it seems to me that you would be
adding work for zero benefit to anyone.

A few years ago, Oprah Winfrey congratulated on her show the winner of
the teacher of the year contest in US because he was able to teach
astronomy to blind students. Through touch and feel, students were able
to "picture" the global constellation of stars under very finely +
specially designed umbrellas for those teaching purpose. It's difficult
for me to explain how the whole thing was made but I assure you
astronomy can be taught to students.

Anyway, accessible image maps should degrade gracefully in text browsers
or in any browser not rendering images.

Gérard
--
remove blah to email me