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Re: accessible tree menus


From: John Foliot
Date: Feb 27, 2009 4:40PM

Seth Kane wrote:
> Please understand that there is a MAJOR difference between Accessibility
> and Usability. Annoying maybe but still accessible.

With all due respect Seth, I have been working in the web accessibility
space for close to a decade (and have been on the WebAIM list since Feb.
2002); I do not need to be told by you that there is a difference between
usability and accessibility.

> Web accessibility means that people with disabilities can perceive,
> understand, navigate, and interact with the Web.

No it means *people* can perceive, understand, navigate and interact.
Adding the term "disabled" misses the point completely - what does
'disabled' mean, exactly? That my 75 year old father's vision isn't what
it used to be - is that a disability? He doesn't think so - he's just
getting old. (FWIW, he struggles with this type of menu as well, and has
asked his son, the web accessibility guy, why sites continue to use them.
My answer? They don't fully understand the issue Dad...)

"In order to truly serve users with disabilities, accessibility must
mean more than simply providing "direct" access through assistive
technologies bundled with software, and more than providing the capability
to add such assistive technologies. It also must mean designing user
interfaces that are easier to use for users with disabilities as well as
users "without" disabilities by taking their needs into account when web
pages are designed."

> The thread started by someone asking if there was a way to create an
> accessible drop down or DHTML menu and the fact is YES there is. Now I
> will agree that most people using these overuse the amount of
> information present but your statements are closed minded by stating
> things like suckerfish or dropdowns in general are not accessible.

To be precise and clear, the 'techniques' being used can be made
accessible to adaptive technology. Whether or not content authors should
continue to use them remains very much open to discussion and debate. In
the example you posted (Harvard), the use of the dropdown menu causes
usability issues for many types of users, and is, in effect not very
accessible to more than just screen reader users.

This does not mean that authors should *never* use these types of menus,
but what it *DOES* mean is that there is a risk that their usage will
frustrate a certain percentage of your target audience. Further, there is
a very real risk that using these types of menus can quickly escalate
beyond annoying to out-right difficult without some clear guidance and
understanding of *ALL* the issues, not just the technical ones.
Overloading of links is one such issue... heck, if you can hide 10, might
as well hide 20, or 30, or 80... (and yes, I've seen that kind of menu too
- http://bullion.nwtmint.com/) It is cognitive overload gone wild.

> NO WHERE in any published guidelines does it say how much accessibility
> is too much.

Or too little. Your point?

> If there were only 9 Links on the page (3 Navigation Items, 3 Items Per
> Drop Down) would you still say it is not accessible?

The latest guidance, WCAG2, uses the term 'perceivable' (to attain
awareness or understanding of - Merriam-Webster), and I posit that having
in excess of 30 links collapsed inside a fly out menu affects many users
ability to perceive the totality of the navigation menu - they cannot see
the forest due to all of the trees. Would 9 be acceptable? Perhaps, but
when was the last time you saw a dropdown/fly out menu such as this with
only 9 links? [an example would be great]

> Now specifically with the Audio annoyance. Ask any Speech Reader user
> if they prefer using quick functions to bounce around to Headers, Link
> List, Form Controls, etc.. over just sitting there like a dead fish and
> listening. Even on the WEBAim Screen Reader Study is says: 76% of users
> always or often navigating by headings.
> http://webaim.org/blog/screen-reader-survey-results/

While WebAIM's survey results are a fantastic resource that our community
has needed for some time, you cannot simply paint all users as having one
particular way of interacting with the web. Classifying this as a
screen-reader issue simply illustrates a lack of deeper understanding of
the real issue - a major one being what I referred to previously as the
cognitive overload issue.

"Working memory is generally considered to have limited capacity. The
earliest quantification of the capacity limit associated with short-term
memory was the magical number seven introduced by Miller (1956). He
noticed that the memory span of young adults was around seven elements,
called 'chunks,' regardless of whether the elements were digits, letters,
words, or other units."

Whether or not you are prepared to admit it, first time or infrequent
visitors to the Harvard site will be assaulted by 62 link options off the
home page. Blind or not, this amount of choice ultimately results in few
concrete choices - there are simply too many to process - and this may in
fact impact on users with cognitive impairments, users whose primary
language is not English, lower-literacy users, etc.

"Unlike higher-literacy users, lower-literacy users don't scan text. As
a result, for example, they can't quickly glance at a list of navigation
options to select the one they want. They must read each word in each
option carefully. Their only other choice is to completely skip over large
amounts of information, which they often do when things become too
"According to the U.S. Department of Education's National Assessment of
Adult Literacy, 43% of the U.S. population has low literacy. (Literacy
levels are roughly the same in other advanced countries, though slightly
higher in Scandinavia.)"

Some studies are now suggesting that too many choices is actually
detrimental to end users [http://tinyurl.com/6kbtff], and that too many
choices has a physical cost associated to it as well:

"There is a lot of physical overhead to thinking. The brain needs a lot
of energy to think, and hard thinking can actually lead to measurable
decreases in the body's energy supply. In addition, there are a number of
crucial brain chemicals that are limited resources that must be conserved
for important thinking tasks. So, we often try to think as little as
possible, unless there are great benefits to be obtained from that
thinking or very serious costs to be incurred by not thinking."

Further, fly out and dropdown menus have usability issues associated to
those users with mobility impairments - often those who have
fine-motor-control issues struggle with getting the mouse in the right
location to activate the dropdown or fly out.

"I recommend against using "fly-out" menus in general... As a general
usability issue, they're often described as "slippery" by able-bodied
users, and can certainly create frustration among those with motor
[NOTE: PDF File]

Finally, people who use screen magnifiers often find these menus hard to
use. When the screen is magnified extensively, dropdown items can
sometimes disappear off screen. In some cases, it is impossible to
navigate to the dropdown items, as moving the visible screen area
deactivates the dropdown.

> There are great comments and input on this topic, however I think some
> people become biased by the products they sell, ways THEY ALONE use the
> web and stop really focusing on the goal. To make it as accessible to
> as many possibilities.

Nope, I've not lost that focus - instead, I think I've actually stood back
further than you and spent some real time investigating the pros and cons
of this type of navigation, and have concluded that overall, they still
remain access barriers to a significant portion of the population.

Instead, I think *you* are trying to justify the usage of a tool that
still has some serious issues attached to it, simply because some clever
developers have come up with a 'technical' solution to exposing this type
of menu tool to adaptive technology, and that they look "cool" and make
sites "prettier" to a Presentation Layer Developer.

> I have listed below the definitions of
> accessible...
> 5: capable of being understood or appreciated

I think the above has addressed this definition directly.