On Mon, 1 Oct 2001, Jeremy Rogers wrote:
...
> It used to be possible to download a demonstration version of ORCA
> from Erasmus University in Rotterdam, but they are redesigning their
> site and it does not seem to be available at the moment.

ORCA descriptions here:

Self-contained patient data in ORCA to cope with evolving vocabulary
http://www.amia.org/pubs/symposia/D004683.PDF

Can data representation and interface demands be reconciled? Approach in
ORCA
http://www.amia.org/pubs/symposia/D004235.PDF

...
> The principle problem we encountered with ORCA was that although
> individual nodes in the user interface navigational tree structure
> have unique names, the meaning of each node (and often also the links
> either side of it) is not constant but changes depending on which
> path it finds itself in. The best example of this would be the
> terminal qualitative adjectival nodes, like 'soft', whose conceptual
> representation is different when preceeded by the prior node 'faeces'
> as opposed to the node 'heart murmur'.

I raised this very issue in the context of the Odyssee system back in May
2001 on this list:
http://www.mail-archive.com/[email protected]/msg04815.html

The three critical issues that I posed were:
1) collisions (e.g. 'soft faeces' vs. 'soft heart murmur')
2) contradictions
3) addition / maintainence of concept space over time

...
> The reader will bring the missing models with them when they read the
> text, just as they do when they read the structure.

> Effectively for machine processing, however, where these rich domain
> and context models are missing, the true total conceptual meaning of
> an individual path may not be *reliably* computed by reference to
> concepts assigned to the nodes or links of which a path is
> constructed.
...

You raised another issue - "4) incomplete description" and identified the
need to provide the "missing model". This is exactly why I have been
hoping to interest some of you to study Cyc (www.opencyc.org) and discuss
your work within that context. Cyc's major aim is precisely to address #4.

Personally, I do not believe #4 can be solved without something like Cyc.
And therefore, I did not include it in my original critique of Odyssee.

I look forward to hearing your thoughts.

> meaning of *some* paths might be computed from their substructural
> nodal mappings to an ontology,

Right. I would further argue that's the best we can ever do - even with
elaborate context model and world knowledge (e.g. Cyc). *Some*
understanding is all I can expect from posting this message, for example.
A richer "context"  model can provide greater "confidence" in the semantic
interchange - but can never guarantee reliable computation from *all*
possible paths.

> we don't know whether it is possible
> to automatically identify in advance which paths are the dangerous
> ones.

Odyssee provides FIL Guides which tell you which paths are safe. A
more useful approach IMHO. :-)

Details about Fil Guides here:
http://www.mail-archive.com/[email protected]/msg03936.html

> The alternative situation is that, in order to migrate a recorded
> path into an environment in which ontological processing occurs, it
> is necessary to enumerate every possible path that the interface
> could ever generate and then manually declare the correct mapping for
> each individual path to a concept within the external ontology.

What do you mean by "external ontology"? Do you mean a "foreign ontology"?

> If this is the case, then the recorded structure of a path remains
> important in its role as part of the unique identifier of that path,
> but it is not useful in deciding how that path as a whole relates to
> concepts in some remote ontological system.

It seems that ontology-to-ontology mediation will be necessary! This is
precisly my rationale for proposing "Flexible Semantic Scope" and "Late
Binding to Related Concepts"
(http://www.txoutcome.org/scripts/zope/readings/OIO_talk/medinfo2001/overview2).

Best regards,

Andrew
---
Andrew P. Ho, M.D.
OIO: Open Infrastructure for Outcomes
TxOutcome.Org (hosting OIO Library #1)
Assistant Clinical Professor
Department of Psychiatry, Harbor-UCLA Medical Center
University of California, Los Angeles

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