Hi All,
This was recently posted to the UMLS list.
Given some of the issues we've been discussing, I thought others
might appreciate some of the ideas recounted here by Gary Merrill
from GlaxoSmithKline
I have my own take on this very very important issue, but I'd rather
not editorialize on Gary's points - and give you a chance to process
them as he so clearly expressed them. Some familiarity with UMLS
structure is helpful (http://umlsinfo.nlm.nih.gov).
By the way, a site relevant to our efforts is the Open Clinical site
(KM for Medical Care - http://www.openclinical.org/medTermUmls.html).
Cheers,
Bill
Begin forwarded message:
From: [EMAIL PROTECTED]
Date: January 19, 2007 10:52:11 AM EST
To: [EMAIL PROTECTED]
Subject: Re: MRHIER and AUIs
Reply-To: [EMAIL PROTECTED]
William:
I think that was a very good non-techincal summary of some issues
in the
Metathesaurus that can be difficult and confusing. The nature and
role of
AUIs (and their relationships to one another and to the CUIs that they
"realize") can require substantial thought.
I am always a little concerned when I see statements such as "In
an ideal
harmonious world, NLM and all sources would agree, and Meta would
become
a single unified principled
ontology." I do not in fact think that this is necessarily true
(under
some reasonable constraints it is in fact provably false), and
definitely
do not think it should be taken as a disideratum. Perhaps you do not
either, but I wanted to take this opportunity to say that,
particularly in
the context of evolving empirical scientific theories, we should not
expect (and not necessarily even strive for) such a unified ontology.
(There are, of course, those who would disagree.) The history of
science
and the history of philosphy has shown the folly of this, and I would
argue that while striving for a certain "convergence" is desireable,
striving for the one true theory/ontology is not. That's something
of a
digression, but I take the strength of UMLS to lie in providing a
way of
"communicating between" and using mulitple disparate (at times
mutually
inconsistent) world views without imposing a strict ueber-ontology.
Again,
there are those who tend to find the lack of the ueber-ontology to
leave
them feeling insecure and adrift in metaphysical ream of uncertainty.
As I expressed to Chris in separate communication, from my
perspective (as
a very application-oriented user), UMLS provides a usually adequate
representation of "concepts" (via CUIs), and terms/words/linguistic
items
(via SUIs, LUIs, etc.). What it does not provide a particularly crisp
representation of at the moment is "things" -- e.g., diseases
rather than
disease names or disease concepts (that is, the extensional
correlate of
the (intensional) concept/CUI). AUIs are enlisted to support this
to some
degree, but they are somewhat too closely allied to linguistic items
(terms) to carry the genuine semantic weight of
"things" (extensions). At
best, one ends up using sets of AUIs as equivalence classes to
represent
the thing to which each of the AUIs "refers" (though "refer" here
is, I
think, a bit misleading). So in terms of a classic thing/word/concept
semantic hierarchy, my feeling is that UMLS does a good job of the
word/concept part, but the thing part is left a bit "mushy". However,
there is room for substantial debate here, and many of the issues are
unclear.
Largely this is a consequence of construing UMLS as a -- surprise --
meta*thesaurus* rather than a meta*ontology*, and focusing on meaning
relations (e.g., synonomy) rather than more fundamental semantic
relations
(e.g., denotation and extension). I do have some ideas of how
this might
be addressed, but won't even mention them here -- partly because
working
them out requires substantial thought and care, and partly because
I'm not
altogether sure of what the benefit would be (to most UMLS users) to
retrofitting such an approach to UMLS.
------------------------------
Gary H. Merrill, Director
Semantic Technologies Group
Statistical and Quantitative Sciences
GlaxoSmithKline Research and Development
Research Triangle Park, NC
919.483.8456
Bill Bug
Senior Research Analyst/Ontological Engineer
Laboratory for Bioimaging & Anatomical Informatics
www.neuroterrain.org
Department of Neurobiology & Anatomy
Drexel University College of Medicine
2900 Queen Lane
Philadelphia, PA 19129
215 991 8430 (ph)
610 457 0443 (mobile)
215 843 9367 (fax)
Please Note: I now have a new email - [EMAIL PROTECTED]
