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[ How does blind users access graphical information ascharts (flowcharts, organisation chart)


From: Robinson, Norman B - Washington, DC
Date: Sep 11, 2007 8:30AM


I am making the assumption your focus is electronic (online)
information and not printouts. One of the hardest things is to
understand the context of the graphical information. While information
organized visually can take advantage of ordering based on visual clues
and relative placement of information next to each other, as often used
in organizational charts, it is meaningless when linearized. I find it
easiest to evaluate the information sequentially as that is the simplest
use of the information when read using a screen reader.

There is more than one way to do this, but we provide an example in
our USPS AS-508-A Section 508 Technical Reference that may be of use to
you: http://www.usps.com/cpim/ftp/hand/as508a/508a_c6.html#oEx511274mudg
Note if you can view the visual flowchart for the Leadership Team it has
spatial meaning - you need to see the lines drawn from one team member
to the next to understand the organization hierarchy. Also note that as
is typical of these charts, the top of the page indicates the top of the
organizational tree. Consider what would happen if we simply turned the
chart on it's side - personnel on the far right of the information would
be at the top of the organization. Not my best example but hopefully
that is useful to you.

So providing the textual information, with the context is done in
exhibit 6-2.2.1. In our example we provide leading numbers that
indicates hierarchy. Number one for the top of the organization, number
two for the second in line, and where personnel are equivalent they are
at the same level, so you we list the seven individual as numbers "4.1"
to indicate they all report to the manager listed as number "4". Again,
there are many ways to solve this problem, but this is one approach.

As an aside, I'd mention that linearizing your information also
helps reclassify it for badly designed visuals. I find it easier to
comprehend the linear or tabular information as text then I do visually
sometimes. The butterfly voting ballot is an example of this:


Note that if you used a butterfly ballot, you might be confused as
to if you are voting for the individual on the left of the page or the
individual directly across from them on the right of the page. A long
description of the butterfly ballot: The butterfly ballot is a form
organized with a table of candidates on one side with more candidates
listed in a table on the opposing side. The two tables are joined
together with one column that provides indication of the voting choice.
The difficulty in this is that looking at the information it is
difficult to visually track from left to right and ensure you are
entering the vote for the candidate on the left instead of the candidate
on the right. As the list of potential candidates gets longer, this gets
even harder to visually track.

Basically the butterfly ballot is a table with three columns, one
central column use for voting. Even with tags navigating this sort of
information is difficult, but it is much easier to understand when the
textual information clearly identifies your selection. Added to that if
you could somehow apply a different style or linearize the information,
it becomes much easier for _everyone_ to understand.

I hope those examples are useful to you.


Norman B. Robinson
Section 508 Coordinator
IT Governance, US Postal Service
phone: 202.268.8246

-----Original Message-----
[mailto: <EMAIL REMOVED> ] On Behalf Of Lydia De
Sent: Friday, September 07, 2007 11:00 AM
Subject: [WebAIM] How does blind users access graphical information
ascharts (flowcharts, organisation chart)

Does anyone can guide me. I am new in this mailing list and have few
questions and hope to find some answers with you.
How does blind user access graphical information like flow charts,
organisation charts?
What are the most common methods and tools used?
Does it allow a blind user to have the same experience as sighted
What does a blind user think of the accessibility of this kind of
graphics on the web?
Do they have some ideas of what they would like to see happen?
When accessing a flowchart or organisation chart, what kind of
information are they interested in?
I have read a lot on accessibility but didn't find much on graphics
(charts) accessibility except providing text alternatives or long
descriptions, but Is it enough to make charts accessible, some are very
long to describe, is there anything else that exist?
What kind of information do I need to describe?
If I want to check that my complex chart is accessible to a blind
person, what kind of method do I need to use?

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