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Re: Can I make my family tree chart accessible

for

From: Terence de Giere
Date: Jul 22, 2003 6:57AM

Jukka wrote:

Sorry, but that sounds really absurd,
even if you don't accept my
criticism of <DL> abuse in general

Definition lists, while typically using a term/definition pair, are not
entirely restricted to this use. The HTML 4.01 specification states


"Definition lists, created using the DL
<http://www.w3.org/TR/html4/struct/lists.html#edef-DL>; element,
generally consist of a series of term/definition pairs (although
definition lists may have other applications). Thus, when advertising a
product, one might use a definition list:

Lower cost
The new version of this product costs significantly less than the
previous one!
Easier to use
We've changed the product so that it's much easier to use!..."

Also

"Lists may also be nested and different list types may be used together,
as in the following example [a recipe], which is a definition list that
contains an unordered list (the ingredients) and an ordered list (the
procedure)..."

These quotations are from the page
http://www.w3.org/TR/html4/struct/lists.html

Thus, by specification a definition list is not exclusively restricted
to a term/definition pair, but can be generalized to a term or statement
that is extended or amplified by the second half of the pair. If there
is an abuse in the use of a definition list, it begins with this
official specification for HTML 4. What is necessary to avoid is to just
use a definition list for the indented format that typically is the
default presentation in a graphical browser.

A family tree actually presents some interesting problems when trying to
present the tree in a linear text based form. First are the branching
nodes. Nested lists (OL, UL, and DL) can provide the branching nodes.
Tables can provide columns that categorize the generations, but the
internal structure does not provide a good means for the branching nodes
that linearize well. When attempting to provide information found in a
data table in a one column linear form, lists usually work the best. In
this case it seems essential to add some textual description of the
relationships within the "definition" for user agents that do not tell
the user what kind of list is being used. A solution using ordered, or
unordered lists could be better, especially if the semantic implications
of term "definition" are a concern, as they are to Jukka. I also said
Brent Ashworth could *try* a definition list. This was the first thing
that came to mind, but I do not think this is the only possible
solution. For one thing, I do not recall completely how a definition
list is rendered on all the various assistive user agents I have. It may
be that the presentation is not that clearly perceived using this structure.

The main problem is describing the complexity of the relationships. With
each generation the amount of information doubles, it increases
exponentially by powers of two. A visual chart can encompass this
complexity until it gets too large to draw, but as a text/aural
description, I am not entirely convinced there is any good way present
this data in a way that anyone can remember well if the tree is large.
We might even tell it as a story, "My name is Brent Ashworth. Now, my
father, Warren Ashworth, and my mother, Carolyn La Tourette..." which
might be easier to remember, especially if some details about the people
or their lives are included.

Whatever the final solution, a way to describe the relationships rather
than the appearance of the chart is what is required. For an aural
presentation, it might be useful to provide an additional simplified
version of the relationships, describing each generation with the names
in each generation, which provides the general relationship to the
principal, but not the intricacies of the relationships within the
generations. That could be done with a table or lists as well. Unless
one is a family member, or an historian, the full level of detail may
also not be of interest, and a simpler presentation would suffice. A
family tree would make a good experiment for a usability test, to find
the best way to present this information in a non visual manner.

Terence de Giere
<EMAIL REMOVED>




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