Re: Long desk descriptions

Hello Michelle,

On Mon, 17 Jun 2013 16:25:38 +0200, Michelle McManus  
<michelleandremy@gmail.com> wrote:

Thank you for taking the time to write. I have some comments, and some  
questions that I hope will help me understand your perspective better.

> To begin with I am a screen reader user. I enjoy having pictures  
> described in simple yet concise terms that appropriately fit the context
> of the page.

I think this is what the alt attribute, or the alt attribute and title,  
are typically meant to do.

In particular, they should be content that you don't mind hearing when you  
are reading through the page. Longdesc is meant to fill a different case,  
where you want a more thorough description available, but you probably  
don't want to have to read through it every time you read the page, or  
encounter the same image in multiple pages.

> If a long description is necessary having a description open in a new  
> window works well, however, I have found that in a lot of cases this link
> is not coded correctly and the description page does not open.

Yes, it is known that many authors (and in the past even many tools) have  
done a terrible job of the coding. One of my assumptions is that the cases  
where it is done right are useful, and the useless cases are a relatively  
minor annoyance (you learn not to bother for the bad cases, but you can  
benefit from the cases where it is done right).

> So I prefer either having the descriptions contained within the content
> because if the description needs to be long the material probably needs
> to be shared with everyone.

The specification requires that the description is available to everyone.  
It just doesn't require that it is physically copied into the same page as  
the image.

> If it is not appropriate to include the description within the
> content then it is most likely not needed.

Longdesc is primarily intended for descriptions that are not always needed  
every single time the user reads the page, but where the description is  
valuable some times. Please note the use cases in the specification, which  
describe the problems that longdesc solves.

Longdesc allows for the case where the description is included directly in  
the content. It makes it easier to point directly to the description, for  
cases where it doesn't immediately precede or follow the image.

But there are some use cases where it makes sense not to force the  
description to be included in the page:

Sometimes, an image is used in many different places. Instead of forcing  
the authors to copy and paste descriptions many times, when they will only  
be used sometimes, allowing all the usages of the image to refer to a  
description (in the same way that HTML allows all usage of the image to  
refer to a single source for the image data itself) can save a lot of time  
and make it much easier to manage a library of content.

Sometimes, the default visual presentation of the page is extremely  
important to the people who are paying for or creating it. To the extent  
that they will simply refuse to include extensive text describing an image  
if it interferes with their visual design. Allowing for a reliable way to  
get that text is important. Despite 20 years of trying, techniques for  
hiding content except from people who need it don't work, since they also  
exclude people who do need the content that is hidden.

(The "iframe" technique is the most recent example - it works fine for  
screenreaders, but is completely inaccessible for high-contrast usage,  
screen magnifiers, people who zoom the content a lot in the browser, and  
many other adaptations indiciative of people who would benefit a lot from  
having a long description available).

>  Thank you.

Again, thank you very much for taking the time to discuss this.

cheers

Chaals

-- 
Charles McCathie Nevile - Consultant (web standards) CTO Office, Yandex
       chaals@yandex-team.ru         Find more at http://yandex.com

Received on Thursday, 20 June 2013 19:38:33 UTC