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Adding <meta> tags to XML documents

"The ability to create fine-grained links to a document is known as
granular addressability, which is an important characteristic of
knowledge management systems. Unfortunately, HTML's support of this
feature is limited. In order to create granular links to subsets of an
document, the author of that document must explicitly create named
anchors within that document. If the author does not do this, then you
will be
unable to link to anything more granular than the entire document."     (01)

  From Eugene's paper at
  http://www.eekim.com/cgi-bin/dkr?fn=/ohs/purplecasestudy.html    (02)

Now, doesn't the ability to add <meta> tags to an XML document produce
the same kinds of problem? The only <meta> data you can access is data
the original author to provide.    (03)

But if you have semi-solid granular addresses (which allow a document
to be modified and yet retain a high probability of link-accuracy),
then meta-data can be specified outside the document, with links into
it.    (04)

That allows someone other than the original author to add ontological
information at a later date, without disturbing the author's 
interaction with the document.    (05)

Now, file systems introduce a problem. The system breaks down when
material is moved from one document to another. The addresses in the
old document are now gone, and the material gets new addresses in 
the document it is added to.    (06)

Here again, the idea of a "node soup" solves the problem. If the nodes
exist in a primordial soup, and they are strung together to make views
known as "documents", then they continue to exist at their original
address, however they are combined.     (07)

So we can see that considering a "document" as a "view" of nodes taken
from a node soup has important advantages for maintaining link 
integrity.    (08)

Of course, problems still exist. Suppose I point to section "A" of
a document, which looks like this:
     4...    (09)

Now "A" contains items 1-4 underneath it, and the aspect that unifies
items 1-4 may well be the thing I point to with an ontological link.    (010)

The author, though, may decide to create two documents:
     4...    (011)

     3...     (012)

And then create a third segment that unifies the previous two:
     B...    (013)

In this case, the ontological link will be hopelessly broken,
since it will still be pointing to "A" when it should be 
pointing to "C".    (014)

But if the XML documents contains <meta> tags, the same problem
is highly likely to exist! The author could easily make the 
same changes, leaving behind the original (and now inaccurate)
<meta> tags.    (015)

However, if the meta data is stored *outside* the documents,
then a librarian/ontologist is free to correct the problem
without modifying the documents. With <meta> tags embedded
in the documents:
  a) The documents themselves must be modified.
  b) The permissions structure is likely to require
     the original author(s) make the modifications.
  c) Two sets of changes have to be made. The <meta> tag(s)
     must be removed from one document, and then inserted
     into the other. (With external meta data, on the other
     hand, only a single link needs to be changed. Such is
     the value of indirect addressing.)    (016)

In summary, now that the thoughts have gelled in my mind, I
have to say that I am not in favor of embedding <meta> tags
in XML documents. I suspect that using granular addressing
and maintaining meta data externally makes a lot more sense.    (017)