SGML: Topic Navigation Maps

Subject: Re: Topic Navigation Maps (WG8) Any solutions for Index-words?

Date: Fri, 07 Mar 1997 08:50:17 -0800

From: Christophe ESPERT <C.Espert@der.edfgdf.fr>

Newsgroup: comp.text.sgml


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Michael Leventhal wrote:
> 
> In article <331EA4A8.10D6@scup.no>, Linda Christoffersen  <lch@scup.no> wrote:
> >I read that WG8 work on an application (Topic Navigation Maps) that will
> >handle Index lists and contents and more....
> >
> >Does anyone have more information?
At Electricité de France we have used Topic Navigation Maps in
the Electronic Library Project.  Document Type Definitions have
been designed using HyTime and the CApH architecture.
We have about 70,000 SGML/HyTime documents stored in an O2
object database.  This is only a prototype now but the database
is about 5 Gbytes.

The most difficult part was to prepare the documents and particularly
to markup the occurrences of the topics in which wa wished to
navigate.  Our documents deal with project management and activities.
So it made sense for instance to say that project "XYZ" was an
interesting topic for the users of our system.  Now we had to
find all the occurrences of the string XYZ in all the documents
and mark them up.  Of course there are ambiguities because XYZ
could be a usual word, not only the name of the project...
So the main problem is the quality of information and how you
mark it up.  It does not seem reasonable today to ask the information
producers to indicate potential anchors of hyperlinks while authoring
their documents.  At this point it should be interesting to use
something like SDQL so that a simple query could give us back
all the occurrences.  But the SDQL engine would have to use some
kind of full-text indexing mechanism to be efficient here.

Today the prototype shows a good degree of navigation but by improving
the quality of the information, it will reveal more power.
The documents in the O2 SGML/HyTime database have been full-text
indexed but the documents' structures have been preserved.  It gives
us an interesting query interface.  All this is accessible through
a Web interface.  The SGML documents are converted on the fly to
HTML using a DSSSL-like STTP process.

In my opinion Topic Navigation Maps are really a great means to
offer some kind of structured navigation.  Today it is by far the
best solution for hyperlinking documents.

Best regards,

	Christophe ESPERT