On Mar 27, 2008, at 3:58 AM, Kashyap, Vipul wrote:
It seems to me that we shouldn't throw out an important distinction
just because SNOMEDCT has terms that should be expressed in
information model.
[VK] I did not mean to throw out the distinction, but to position
the distinction differently. For instance, I would still
differentiate between SNOMED-CT the information model
and SNOMED-CT the terminology, just that I would view SNOMED-CT the
terminology as a specialized case of the SNOMED-CT the information
model.
So, would propose that the notion of an information model "subsumes"
the notion of a terminology.
OK, we disagree on this point. I'd just point out that, if you are
interested in working with HL7 RIM or BRIDG, you have a conceptual
mismatch with them.
To me, information model = structure and types of information
(statements or expressions uttered, recorded, written by somebody).
[VK] This is part of the disagreement. How about:
Information Model = Semantics and types of information ...
I am thinking of "information model" as a kind of information-content
entity in BFO.
Informational entities (e.g., observations, eligibility criteria)
make reference to things in the world through terminology codes
(e.g., 57054005 for acute MI in SNOMEDCT).
[VK] You don't need a terminology to do that. For example, Acute MI
could be a class in the Information Model. Further more it could be
a sublcass of the Observation/Problems class.
From the modeling point of view it's not necessary, This decision of
referencing external terminology codes appears to be taken due to
implementation and scalability considerations..
If your Acute MI is a subclass of Observation/Problem, then instances
of "Acute MI" class are observations of Acute MI, not instances of the
disease MI. An "observation" does not have severity, location, and so
on. You lose the ability to talk about properties of the things in the
world. An information model refers to codes not because of
implementation concern, but because component parts of informational
entity are also informational entities, IMHO.
Samson
