Re: advice on alt text for image maps

Hi Jukka, comments inline

--

Regards

SteveF
HTML 5.1 <http://www.w3.org/html/wg/drafts/html/master/>


On 26 December 2013 21:34, Jukka K. Korpela <jukka.k.korpela@kolumbus.fi>wrote:

> 2013-12-24 19:26, Steve Faulkner wrote:
>
>> I have made some modifications to the example:
>>
>> http://www.w3.org/html/wg/drafts/html/master/embedded-
>> content-0.html#image-maps-0
>>
>
> It's much better now, with a realistic example of a situation where one
> would meaningfully use a client side image map (a real map, though with two
> active areas only, for simplicity).
>
> There's no general guideline for writing the alt attribute, though. Just
> saying "always provide a text alternative for the image" does not give
> guidance on what the alternative should be. And I'm not convinced of the
> adequacy of the example text either.
>

sure , will review your suggestions and make some edits.

>
> The content in the example would read as something like the following in a
> presentation that does use images (I'm denoting spacing or pauses between
> paragraphs with isolated hyphens "-" here):
>
> "View houses for sale in North Katoomba or South Katoomba - Map of
> Katoomba (link) Houses in North Katoomba (link) Houses in South Katoomba"
>
> How does the text "Map of Katoomba" help here? I would say that it is just
> disturbing. It does not help to know that there is a map that you do not
> see. In this case, alt="" would seem to be the appropriate attribute.
>

For SR users the presence of the image is announced, so they would get 'Map
of Katoomba (Graphic)'...  Likewise for users with images disabled, in most
user agents an indication that an image is present, is displayed.

(from checking Chrome, IE , firefox a major, but unrelated issue is that
when the image is not visible, there is no indication of the links. (alt
not displayed))

In the case of SR users it is not always the case that they cannot see the
image, for those users providing the alt provides contextual info which can
help them make sense of the image content.


>
> Looking now at an earlier suggestion of mine, I realize it was partly in
> error:
>
>
>  If an img element has a usemap attribute and is thus associated with an
>> image map, the alt attribute value describes the image as a whole in the
>> context. This means that it acts as a caption for the collection of the alt
>> attributes of the area elements, so that all these attributes together can
>> be used as a captioned menu of choices, in a situation where the image is
>> not seen.
>>
>
> The word "description" is bad here. There is normally no point in
> describing a map to someone who does not see and who has an alternative
> presentation to use, namely something that is effectively a list of links
> (corresponding to areas in the map, but you don't usually need to know
> that).
>
> So let me rephrase it:
>
> If an img element has a usemap attribute and is thus associated with an
> image map, the alt attribute value should normally be empty. The reason is
> that the alt attributes of the area elements, together with adequate
> content before the img element, work as a suitable user interface when the
> image is not displayed.
>
> [the example could go here]
>
> However, sometimes the img element might not be preceded by content that
> fully indicates what kind of a choice is expected from the user. This could
> happen if the image is expected to be at least self-explanatory in that
> respect. In that case, the alt attribute of the img element should contain
> text that tells what the sequence of links to follow means and how it is to
> be used.
>
> For example, if the image represents a map of Europe, with countries as
> active areas, and the image is preceded just by generic text like "Please
> select a country:", then the alt text should say e.g. alt="(The menu
> consists of the countries of Europe)". The reason is that although this
> European context is usually obvious when the image is seen, it need not be
> obvious at all to someone who only sees or hears a longish list of country
> names.
>
>
Ok get your drift will work on it.

> --
> Yucca, http://www.cs.tut.fi/~jkorpela/
>
>