A recurring constraint through the majority of use cases is that forcing a visual encumbrance on sighted users by adding long description text in-page or adding a visual link indicator in-page to a long description adds visual clutter for sighted users.
Jonas Sicking publicly acknowledged and accepted that this constraint is valid in his change proposal saying that,
page designers often have quite strict requirements on the visual appearance of the page and it would likely negatively impact the level of accessibility support if contents specifically for for example screen readers had to be provided within those requirements.
A forced visual encumbrance is a critical and significant constraint for designers, visual artists, and marketers because of usability and aesthetics.
Clutter is an important phenomenon in our lives, and an important consideration in the design of user interfaces and information visualizations. Many existing visualization systems are designed to reduce clutter by filtering what objects or information the user sees... Tips for designing web pages, maps, and other visualizations often focus on techniques for displaying a large amount of information while keeping clutter to a minimum through careful choices... [Rosenholtz et al., Feature Congestion: A Measure of Display Clutter (PDF)]
For sighted users, the consequences of adding a redundant visual
text description is information overload which wastes time and
taxes attention at the content's peril. It would be akin to having
the value of the
alt attribute visible by default or
providing visible indicators of it. Making such features visible by
default would cause needless work for designers to hide them or
frustration to the majority of sighted users if designers didn't
Removing such visual clutter increases understanding and actual time-on-task for the majority of sighted users. This is where visual design plays an increasingly important role. It is well known that reducing clutter improves usability.
The statement from cartoonist Kyle Weems provides first-hand author testimony that a default visual indicator on-screen is unacceptable due to this constraint. As Kyle explained, designers object to being told to use visible links. In this use case it is illogical and redundant to recreate the dialog of a series of cartoon speech bubbles directly after the cartoon from a visual design perspective. In these types of cases the aesthetic principle of the artist will always trump 'data' requirements when those requirements become onerous. Aesthetic principles restrict the way a solution can be provided. Ignoring such author constraints is ignoring reality.
longdesc's is natively free from a visual
encumbrance. It solves a problem as it allows accommodation,
personalization of content in accordance with a target
audience's needs and capabilities.
As Suzanne Taylor and Ed McCoyd, Esq., of the Association of American Publishers (AAP) testified to the HTML working group,
longdescattribute does not impact the visual design. So, authors do not have to worry about how the text might impact the visual user experience. Authors can, therefore, focus on the experience of students and instructors with visual impairment while they write text alternatives. This focus on the primary audience helps authors create text that is well-suited for its purpose.
AbilityNet discuses how hiding content from view optimizes browsing experiences for two user groups,
Hiding content from view but enabling it to be read out by screen readers enables the web developer to provide additional information that is helpful for the screen reader user. This would enable the screen reader user to understand the content of the web page or the way the web page is constructed without compromising on design. This is particularly useful for elements and areas where there is not enough text describing the area or element ...Hiding content from view can enhance the usability of the website for screen reader users without compromising on design. Visual users will have no indication that these design elements are present resulting in visual and non-visual users having the optimum browsing experience.
This constraint has been amply evidenced with the documentation
eighteen hundred real world images that do not
force a visual encumbrance for a long description by
longdesc. As this compelling pattern evidences,
circumstances do indeed exist where page authors need, desire, and
longdesc due to this constraint.
Scott Berkun has explained the myth of discoverability,
The myth of discoverability, in concise form: The belief that all good user interfaces make all things in the website or product utterly and extremely discoverable, and any design that makes an element (button, link, etc.) less than extremely discoverable, can't possibly be very good, and should be thrown away, to the embarrassment of the designer...All things can not be easily discoverable because everything is limited.
The fact is that, some people may want or need to consume or access long description content that doesn't force a visual encumbrance but do not use assistive technology (AT). The following sighted people may be aided by access to a longdesc:
- Users who have a cognitive or visual impairment.
- Users with either a keyboard or pointing device without screen reader or assistive technology.
- Users with a custom input accommodation, such as a mouth-stick or sticky keys.
- Users who have small screens (e.g. mobile phone or screen magnifiers).
- Users who turn off images to decrease bandwidth use in order to lower their Internet usage fees.
- Authors, for ease of authoring, testing, and maintenance purposes.
longdescDiscoverability Tools Fulfill These Use Cases
No discoverability tools exist for proposed solutions such as
tools exist for
longdesc. These tools are used by
sighted authors and others. On March 11, 2011, professional content
producers at the Digital Image and Graphic Resources for Accessible
Materials Center (DIAGRAM) addressed
for other users.
Their testimony states:
features developed to help people with specific disabilities also assist other users, and this is true for long image descriptions. Today, for example, Firefox and Opera allow the user to open a context menu over an image and choose to see the long description on the screen, if @longdesc is included with the image. This is an excellent tool for assisting sighted students with learning disabilities who need textual reinforcement when deciphering the contents of a complicated image.
longdesc in HTML5 change proposal provides a
solution to the forced visual encumbrance constraint while specifying
discoverability functionality for all who want access to the
description. The claim that
longdesc isn't exposed to
some users is outweighed by the concrete examples of it being
exposed in accessible ways and is as ludicrous as suggesting that
<img> element should be removed from HTML5
because its graphic contents cannot be disclosed to users who elect
to use Lynx or similar.
On May 5, 2012, HTML Co-Chair, Maciej Stachowiak stated,
if a UA can give a better experience i think they should be encouraged to try
To help browser vendors in this effort in the future, new
text has been specified for the 10.6.1 rendering section. which
longdesc can be made discoverable. It
will encouraged to them to improve support. As Anne van Kesteren
has said, examples
in the specification serve as an incentive to vendors:
It's an incentive to get the software fixed.