Screen Readers and Complex Graphics

[Blount, Patricia A]

Good afternoon, all,

Has anyone had any experience writing for 508 Compliance? 

(For our international colleagues, Section 508 refers to the US
Workforce Rehabilitation Act of 1973, which mandates (partly) that all
information be developed so that it is accessible to people with
disabilities.) 

Specifically, I am struggling to write "Alt-Text" descriptions for
complex graphics that go beyond "Graphic of product architecture" so
that visually impaired people using screen readers will get more than
"Oh, here's a graphic and another one..."

I know Alt-Text should describe the graphic's function or purpose and
not merely what it looks like. But actually writing such text is proving
to be very challenging. We're limited to a field about 50 characters in
length and some of our graphics are highly detailed. 

It's difficult to ask this question without actually sending you all a
representative graphic to play with, but I'll start by describing how it
looks first. 

Consider a typical network architecture graphic. These usually resemble
organization charts, with a master server at the top, a few secondary
servers beneath it, and each secondary server may have a bunch of
clients connected to it. Suppose the secondary servers include Email,
File and Print Servers. 

One such graphic shows alerts originating at the client level and being
passed up the architecture to the master server. They could also
illustrate how you configure the product, which servers are doing what,
or even how data flows within the schema. 

The paragraph that introduces such a graphic is typically lengthy. The
graphic is provided to help readers conceptualize all of that text. What
I find myself doing is writing things like "The ankle is connected to
the shin connected to the thigh connected to the hip connected to..." 

I'm making myself dizzy... :) 

Given the character limitation, it seems my only option is to focus on
the graphic's main point. For example, "Alert policies set on all
machines forward alerts to servers, which in turn, forward the alerts to
the Alert Manager running on the master server." 

The graphic shows a lot more detail, such as cell phone notification and
the timing of these alerts, where to find error logs, etc., etc.  

I see no way to encompass everything shown in that graphic in 50
characters or less. Is it permissible to write Alt Text that focuses on
a very limited portion of the overall graphic?