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Discussion of "Evidence" from HCLSIG

From: Kashyap, Vipul <VKASHYAP1@PARTNERS.ORG>
Date: Mon, 18 Jun 2007 11:43:40 -0400
Message-ID: <DBA3C02EAD0DC14BBB667C345EE2D124428949@PHSXMB20.partners.org>
To: <public-xg-urw3@w3.org>
Cc: <public-semweb-lifesci@w3.org>
I think there is a very relevant discussion under way in HCLSIG which has
ramifications for our attempts to build an Uncertainty

Ontology. The wiki URL is included below, just in case someone may find it









Vipul Kashyap, Ph.D.

Senior Medical Informatician

Clinical Informatics R&D, Partners HealthCare System

Phone: (781)416-9254

Cell: (617)943-7120



To keep up you need the right answers; to get ahead you need the right questions

---John Browning and Spencer Reiss, Wired 6.04.95


From: public-xg-urw3-request@w3.org [mailto:public-xg-urw3-request@w3.org] On
Behalf Of Mitch Kokar
Sent: Monday, June 18, 2007 11:39 AM
To: public-xg-urw3@w3.org
Subject: RE: Model and sources of uncertainty




So first of all I'd like to say that all I tried to do is read a couple of
papers (two of them are listed on the web site) that discuss various types of
uncertainty and then make an attempt at reconciling multiple views of the terms
used in the various approaches into a single ontology. In other words, the
notions I put in the ontology are not my inventions - they are defined in
various papers.


During this weekend I tried to understand the feedback I received from the group
and then tried to see whether the current ontology is sufficient or it needs to
be extended. I came to the conlcusion that we might need to extend it a bit. I
have not made the changes in the graphics, as yet, since I didn't want to put
too much effort into the changes before first coming to some agreements. 


However, in order to make the discussion more focused, I added some textual
descriptions of the terms used in the ontology (on the Wiki).


So here are my replies to the issues raised by the group, mainly by Paulo and
Vipul. I believe gstoil is in agreement with me.


1. Unreliability of the source: In the current Uncertainty Reasoning Ontology,
let's call it URO for now, this would be modeled by representing the source as
an instance of World. Thus there would be a sentence about the source A  "Source
A is 33% reliable." Then the notion of "33% reliable" would have to be specified
using one of the Uncertainty Types.


2. Dissonance: I added one more type to UncertaintyTypes - Inconsistency. I
believe this would capture dissonance, but if not, we could then think a bit
more about this issue. I mean here logical inconsistency, i.e., when there is no
model for a sentence. I don't mean existence of evidence for and against a
specific hypotheses (which is just fine within the probability theory).


3. Incompleteness: I would also say that incompleteness is not a type of
vagueness. But it might be interpreted as a kind of ambiguity due to the lack of
sufficient information for resolving the question of whether a specific world is
a model of the sentence or not. But then we could also add another class
(Incompleteness) to the types of uncertainty.


4. Inconclusiveness: I believe I understand what it is, but I don't quite see
how this is a type of uncertainty. Perhaps I am missing something here? But it
looks to me more like redundancy, i.e., a sentence does not add to the existing
knowledge since it's already in what can be inferred from the knowledge we
already have. Please correct me if I am wrong on this.


5. Interpretation: I believe this is about sensors through which we perceive the
world. Similary as in point 1 above, this is a sentence about an instance of
World (sensor) whose accuracy would have to be specified in terms of this
ontology using one of the probability types.


Vipul's issues:


Statement vs. belief: Perhaps we could incorporate beliefs in the ontology, but
this would seem to say that someone makes statements that he/does not believe
in. It seems to me that in that case the distinction would be between the agent
who believes in the statment and someone else who just refers to that agent's
beliefs. We could possibly subclassify Statement for this purpose. Vipul - could
you say in OWL what changes you are proposing?


I agree that UncertaintyModel could be termed somehow differently. We could
possibly add some synonims to the ontology.


It seems that the rest Vipul's statements are comments or clarifications. 








	From: public-xg-urw3-request@w3.org
[mailto:public-xg-urw3-request@w3.org] On Behalf Of Paulo CG Costa
	Sent: Thursday, June 14, 2007 5:59 AM
	To: public-xg-urw3@w3.org
	Subject: Model and sources of uncertainty

	Dear Mitch, 



	The model on types of uncertainty lists only three of them:

	1 - Vagueness

	2 - Randomness

	3 - Ambiguity


	How about:

	- unreability: knowledge from a source that is not 100% trustfull,

	- dissonance: we see the same piece of information, but each have a
distinct interpretation,

	- incompleteness: which is not vagueness, since you can have a clear
view of just part of the information,

	- inconclusiveness: we have clear, deterministic, non ambiguous
information, which is also complete, we both agree upon it, and the source is
reliable, but it is not enough to come up with any conclusive assertion.


	Also, regarding the sources of uncertainty, how about interpretation? Is
it within the epistemic label?

	I know that our lack of complete knowledge of the things that happen in
the world (even if they are deterministic) is the cause of (epistemic)
uncertainty. However, it is not so clear to me that two people with complete
knowledge about a deterministic phenomena, but with distinct interpretations of
what they see are an epistemic source of uncertainty.

	The uncertainty doesn't come from an aleatory source and is not caused
by incomplete knowledge, but it is an artifact of how those human sensors
perceive the phenomena.









	Dr. Paulo Cesar G. da Costa

	Assistant Professor - C4I Center

	George Mason University

	Fairfax, VA - USA

	http://mason.gmu.edu/~pcosta <http://mason.gmu.edu/~pcosta> 

	pcosta@gmu.edu <mailto:pcosta@gmu.edu> 




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Received on Monday, 18 June 2007 15:43:58 UTC

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