Dear Richard,
On 28/7/2014 11:41 ??, Richard Light wrote:
Martin,
I thought that a major merit of the CRM was that it was an abstract
model, which could be instantiated using whatever technology was felt
to be appropriate. That being the case, I would be concerned if
RDF-specific techniques were presented to the world as the only way in
which a particular challenge ("implementing argumentation systems
...") could be tackled using the CRM. Or are you talking specifically
about RDF implementations of the CRM?
I share your concerns :-) !
Why can't "premises and conclusions" be modelled using reification, so
they can then be given a unique URI? This is the sort of approach
which the BM has successfully deployed, as I understand it. I would
be grateful if someone could provide a really simple concrete example
which shows the need for the named graph approach.
Your are right!
Actually I see the "Named Graph" not as a particular RDF feature, but at
the level of abstraction that Simon pointed
out: A set of propositions with a "historical" identity which is not
reduced to the identity of the set itself.
The CRM uses an abstract data model of classes, superclasses,
properties, superproperties etc., which is more or
less the stable core of all data structures and KR models used so far in
industrial systems. We have however adopted
the term "property" from RDF, just to reduce the semantic gap for people
now. Originally, we used TELOS terms, but KIF, OIL was equally compatible.
The requirement to introduce argumentation structures into consistent
graphs of propositions is relatively new.
Reification is an atomic mechanism, which does not allow for describing
that a set of propositions is believed
together. Therefore it looses an important part of the semantics of
argumentation. A Named Graph is in my mind
an abstarction which subsumes reification. Reification is a workaround
using a syntax which has not foreseen the problem before. Named Graph is
a NEW logical construct not found in any other industrial KR model, and
born out of a necessity that first showed up when integrating different
sources. (Before, one could say AI just slept in a one-truth cyberworld
with a god-like user or math on top of reality).
I believe we need the Named Graph construct as a logical form, not as an
RDF syntax, if we want to integrate
provenance of knowledge with the CRM. So far, we have evidence of two
real-life data structures, one is
archaeological excavation records, and another description of medieval
book-bindings, which systematically
register source of evidence and concluded facts. E.g., geometric
topology of stratigarphic units and microsopic
stratigraphic interface properties are used to justify chronological
sequence. In a simple model, this is atomic,
in a more general, it is probabilistic Bayesian. So, we would need a
"Typed Named Graph", which restricts the
propositions in the Graph to a certain schema (topology, chronology),
and then a relationship "is evidence for"
between the typed named graphs. The assertion itself forms part of the
belief implicit in the archaeological
record.
If there is any logician on this mailing list, a proper formulation of
such a construct and an abstract syntax for the CRM would be great to
have!!!
We will try to suggest a graphic primitive, which is a bubble around the
propositions with a "hot spot" on the
perimeter.
Suggestions most welcome!
To pick up on the suggestion of using the AAT as an example: in what
way is the AAT a named graph? Surely it's a SKOS Concept Scheme
(plus)? I think it would be impossible to give an example of a
"well-known" named graph, for the reasons Simon has been explaining.
Named Graphs are new, so none is really "well known", but I would regard
a skosified AAT as a Named Graph,
as well as all the RDF junks for LoD, once RDF regards any RDF file as a
Named Graph. The only condition is, that
two RDF Files with the same content and different URI are not regarded
as being identical (owl:same_as).
Best,
Martin
Richard
On 25/07/2014 20:25, martin wrote:
Dear Richard,
At least in the implementations we use one triple can be in any
number of graphs, even nested ones
(SESAME, Virtuoso, OWLIM).
The point Steve is making here that Named Graphs are the only way in
which facts in a database can be
described as explicit content of multiple(!) information objects
which are described (creation etc.) in the
same system. There is no other choice for implementing argumentation
systems which explicitly describe
premises and conclusions as propositions in the database.
On 24/7/2014 11:03 ??, Richard Light wrote:
I must say that I'm not so sure that named graphs are going to be
particularly useful for implementations of the CRM. As I understand
it (and I don't claim to be an RDF expert), the idea of quads was
invented so that "naked" RDF assertions could be given a "context".
The problem I have always had with that idea is that you only get
one shot at it (i.e. you can only assign one context to any given
triple).
Surely (a) we need to be able to express multiple contexts for
statements made within the CRM, (b) we have already developed a rich
enough use of RDF to allow us to do so.
Richard
On 24/07/2014 05:57, Simon Spero wrote:
The AAT might work.
I'm not entirely sure that named graphs are propositional objects
as defined in the CRM, but I think the definition is loose enough.
Named graphs are not graphs that are named; they are a tuple of an
IRI (which is a name), and graph (which is the set of
propositions). If the name is a proposition, it is not one in the
graph it is associated with.
If Propositional objects can include parts which are not
propositions then there is no problem- though it would seem more
natural to have information objects only part of which are
propositional.
That would be a bit too big a change this far down the road ; if
named graphs can't fit directly, graphs themselves would; these
could be part of named graphs.
I am not sure if "The encoding structure known as a "named graph"
also falls
under this class, so that each "named graph" is an instance of an E73
Information Object." is the right way to say it.
May be better "information encoded as named
graphs may represent instances of E73 Information object including an
explicit representation of contents".
Since it is an encoding construct, it may represent other things as
well. In a sense,
it is trivial that any RDF File is an information object, but it is
not trivial if a part of the content
of an RDF File represents (,not "is",) an information object in its
own right.
I would rather put that at the end of the scope note as an
implementation note.
On Jul 24, 2014 12:15 AM, "Stephen Stead" <ste...@paveprime.com
<mailto:ste...@paveprime.com>> wrote:
Can you think of a named graph that would be sufficiently
iconic to make a
good example?
Rgds
SdS
Stephen Stead
Tel +44 20 8668 3075 <tel:%2B44%2020%208668%203075>
Mob +44 7802 755 013 <tel:%2B44%207802%20755%20013>
E-mail ste...@paveprime.com <mailto:ste...@paveprime.com>
LinkedIn Profile http://uk.linkedin.com/in/steads
-----Original Message-----
From: Crm-sig [mailto:crm-sig-boun...@ics.forth.gr
<mailto:crm-sig-boun...@ics.forth.gr>] On Behalf Of Øyvind Eide
Sent: 23 July 2014 15:12
To: crm-sig
Subject: Re: [Crm-sig] *** ISSUE *** Revision of scope note for E73
Information Object to specifically include named graphs
Dear Steve,
This sounds good to me. Do you think an example of a named
graph should be
added as well?
Best,
Øyvind
On 18. juli 2014, at 08:44, Stephen Stead wrote:
> Dear CRM-SIG
> I would like to suggest the following revision to the scope
note for E73
Information Object. Its intention is to specifically mention
"named graphs"
as being instances of E73 Information Object. As we look at
implementation
of the CRM it is becoming increasingly obvious that "named
graphs" are going
to be a particularly useful tool, it would therefore seem handy
if we
explicitly mentioned that they live in E73!
> Best regards
> SdS
>
>
> Current Scope Note
> E73 Information Object
> Subclass of: E89 Propositional Object
> E90 Symbolic Object
> Superclass of: E29 Design or Procedure
> E31 Document
> E33 Linguistic Object
> E36 Visual Item
>
> Scope note: This class comprises identifiable
immaterial items,
such as a poems, jokes, data sets, images, texts, multimedia
objects,
procedural prescriptions, computer program code, algorithm or
mathematical
formulae, that have an objectively recognizable structure and
are documented
as single units.
>
> An E73 Information Object does not depend on a specific
physical carrier,
which can include human memory, and it can exist on one or more
carriers
simultaneously.
> Instances of E73 Information Object of a linguistic nature
should be
declared as instances of the E33 Linguistic Object subclass.
Instances of
E73 Information Object of a documentary nature should be
declared as
instances of the E31 Document subclass. Conceptual items such
as types and
classes are not instances of E73 Information Object, nor are
ideas without a
reproducible expression.
> Examples:
> § image BM000038850.JPG from the Clayton Herbarium in London
§ E. A.
> Poe's "The Raven"
> § the movie "The Seven Samurai" by Akira Kurosawa § the Maxwell
> Equations
> Properties:
>
> Revised Scope Note
>
> E73 Information Object
> Subclass of: E89 Propositional Object
> E90 Symbolic Object
> Superclass of: E29 Design or Procedure
> E31 Document
> E33 Linguistic Object
> E36 Visual Item
>
> Scope note: This class comprises identifiable
immaterial items,
such as a poems, jokes, data sets, images, texts, multimedia
objects,
procedural prescriptions, computer program code, algorithm or
mathematical
formulae, that have an objectively recognizable structure and
are documented
as single units. The encoding structure known as a "named
graph" also falls
under this class, so that each "named graph" is an instance of
an E73
Information Object.
>
> An E73 Information Object does not depend on a specific
physical carrier,
which can include human memory, and it can exist on one or more
carriers
simultaneously.
> Instances of E73 Information Object of a linguistic nature
should be
declared as instances of the E33 Linguistic Object subclass.
Instances of
E73 Information Object of a documentary nature should be
declared as
instances of the E31 Document subclass. Conceptual items such
as types and
classes are not instances of E73 Information Object, nor are
ideas without a
reproducible expression.
> Examples:
> § image BM000038850.JPG from the Clayton Herbarium in London
§ E. A.
> Poe's "The Raven"
> § the movie "The Seven Samurai" by Akira Kurosawa § the Maxwell
> Equations
> Properties:
>
>
> Stephen Stead
> Director
> Paveprime Ltd
> 35 Downs Court Rd
> Purley, Surrey
> UK, CR8 1BF
> Tel +44 20 8668 3075
> Fax +44 20 8763 1739
> Mob +44 7802 755 013
> E-mail ste...@paveprime.com <mailto:ste...@paveprime.com>
> LinkedIn Profile http://uk.linkedin.com/in/steads
>
> _______________________________________________
> Crm-sig mailing list
> Crm-sig@ics.forth.gr <mailto:Crm-sig@ics.forth.gr>
> http://lists.ics.forth.gr/mailman/listinfo/crm-sig
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*Richard Light*
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--------------------------------------------------------------
Dr. Martin Doerr | Vox:+30(2810)391625 |
Research Director | Fax:+30(2810)391638 |
| Email:mar...@ics.forth.gr |
|
Center for Cultural Informatics |
Information Systems Laboratory |
Institute of Computer Science |
Foundation for Research and Technology - Hellas (FORTH) |
|
N.Plastira 100, Vassilika Vouton, |
GR70013 Heraklion,Crete,Greece |
|
Web-site:http://www.ics.forth.gr/isl |
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_______________________________________________
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--
*Richard Light*
_______________________________________________
Crm-sig mailing list
Crm-sig@ics.forth.gr
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--
--------------------------------------------------------------
Dr. Martin Doerr | Vox:+30(2810)391625 |
Research Director | Fax:+30(2810)391638 |
| Email: mar...@ics.forth.gr |
|
Center for Cultural Informatics |
Information Systems Laboratory |
Institute of Computer Science |
Foundation for Research and Technology - Hellas (FORTH) |
|
N.Plastira 100, Vassilika Vouton, |
GR70013 Heraklion,Crete,Greece |
|
Web-site: http://www.ics.forth.gr/isl |
--------------------------------------------------------------
