Re: SUO: Fw: Multi-Source Ontology (MSO)
>SUO WG,
>
> Philippe Martin has joined this list and proposed the
>Multi-Source Ontology (MSO) as a started document. Is there a second?
>(Only one needed.) If so, this is open for discussion.
I'll second that.
I'm acquainted with Philippe's work since the time he included the
DOLCE ontology in the database. I think it offers an interesting
starting point for the SUO project and, hopefully, it will help in
focusing the work of this group.
Stefano
>Jim Schoening
>
>
>--------- Forwarded message ----------
>From: Philippe Martin <phmartin@meganesia.sci.griffith.edu.au>
>To: standard-upper-ontology@ieee.org
>Cc: philippe.martin@gu.edu.au, jim.s3@juno.com
>Date: Tue, 02 Dec 2003 06:18:11 +1000
>Subject: Multi-Source Ontology (MSO)
>
>Jim,
>
>Thank you for the invitation to introduce the Multi-Source Ontology (MSO)
>of the WebKB-2 knowledge server (www.webkb.org) as a proposed starter
>document. I also thank John Sowa for having made this proposal last week.
>I first introduce WebKB-2 and its underlying approach, then its MSO
>and finally gives URLs for testing and further details.
>
>
>WebKB-2 is a shared knowledge server: it permits Web users to search and
>update a large shared knowledge base (KB) on the WebKB-2 server machine.
>
>WebKB-2 is also a private knowledge annotation server: it can access
>Web-accessible files on users' machines, and execute knowledge commands
>(i.e. statements (assertions and definitions) and queries) in these
>files,
>and optionally add their statements into the shared KB.
>To ease knowledge documenting, the commands may be mixed with other
>document elements (e.g. text in HTML) as long as these command are
>properly
>isolated from the rest (e.g. within special tags). Indexation commands
>also
>permit ueser to link any document element (e.g. any part of an HTML file)
>to
>a statement by a "representation link". Then, such links may be exploited
>to
>display document elements instead of statements in answer to queries.
>
>I have been developing WebKB-2 since January 2000 (financially supported
>by
>the DSTC, Australian W3C office) above an object-relational DBMS called
>FastDB (for the main-memory version) or Gigabase (for the disk-based
>version).
>WebKB-2 is a partial rewriting and extension of WebKB-1 which focused on
>private knowledge annotations and had no DBMS capabilities (persistence,
>transactions, ...). WebKB-1 (developed from January 1997 to december
>2000,
>financially supported by the DSTO, Australian defence research center)
>was a
>partial and Web-based rewriting of CGKAT, a knowledge acquisition tool I
>developed during my PhD thesis (at the INRIA Sophia Antipolis, France)
>above
>the conceptual graph workbench Cogito and the structured document editor
>Thot
>(the code of Thot is now used in Amaya, the prototype browser of the
>W3C).
>
>WebKB-2 and WebKB-1 parse the FS language, which has various
>sub-languages:
>- FT (For Taxonomies), a simple language for links between categories
> (subtypeOf, instanceOf, exclusion, identity, WordNet links, etc.),
>- FCG, my adaptation of CGLF (Conceptual Graph Linear Format) for a more
> readable and normalized representation of expressive knowledge,
>- FE (Formalized-English), a notation structurally identical to FCG but
> with syntactic sugar which makes it look like English,
>- CGLF, CGIF, KIF, ... (they are sub-languages of FS but are currently
> only very partially parsed by WebKB-2; WebKB-1 fully parses CGLF),
>- FC (For Control), some basic procedural control structures,
>- queries on links and graphs (various kinds of graph-matching are
>possible),
>- commands for the various parsing/display options.
>RDF/DAML+OIL is also partially parsed but is is not a sublanguage of FS.
>Knowledge entering/querying may also be done via HTML menus which are
>translated into commands before being sent to the WebKB-2 server via the
>CGI protocol.
>
>
>In WebKB-2, every element (i.e. category (type or individual), link
>between
>categories, or graph (i.e. logical statement that is not just a link))
>must
>have a recorded creator (user or source, represented by a short
>identifier
>and/or a URL). Hence, the expressions "Multi-Source Ontology" or
>"Multi-Source KB". Category identifiers may also include various "names"
>for
>the category, as long as theses names are separated by at least two
>underscores
>(unlike an identifier, a name may be shared by various categories).
>Some examples of category identifiers are:
>- wn#domestic_cat__cat__house_cat (identifier for a WordNet category
> having "domestic_cat" as "key name", plus "cat" and "house_cat" as
>other
> names)
>- wn#domestic_cat (shorter identifier for the same category)
>- #domestic_cat (idem; special shortcut for WordNet categories
>because
> they currently form 92% of all categories in the WebKB-2 default
>ontology)
>- philippe.martin@gu.edu.au (a possible identifier for myself)
>- http://www.webkb.org/doc/ (a possible identifier for the WebKB
>documentation)
>Within graphs, names can be used instead of identifiers when there is no
>ambiguity (e.g. when a name refers to only one category or the signatures
>of
>the used relations permit to discard all candidates categories but one).
>
>A user may add a link between categories she has not created, or use them
>in graphs, unless this leads to an inconsistency with an already entered
>statement (if the knowledge entering is done via commands in a file, the
>parsing of the file continues but no updates will be committed).
>A user may remove an element only if she has created it.
>For safety reasons, addition of links redundant with an already entered
>link are rejected. Addition of redundant or partially redundant graphs
>are
>rejected unless the redundancy comes from the user stating that she
>corrects
>another user's statement via one of the following inter-graph relations:
>pm#corrective_specialization, pm#overriding_specialization,
>pm#corrective_generalization or, if none of the previous ones apply,
>pm#correction. For example, assuming that oc#statement_on_bird_28 is the
>identifier for the statement "birds fly" (in FCG: [any bird, agent of:
>a flight]; in FE: `any bird is agent of a flight') created by the user
>oc,
>I can state via the following FCG that I believe that a corrective
>specialization of that statement is that "according to a study by
>Foo@bird.org, in 1999, 93% of birds in good health are able to fly":
> [oc#statement_on_bird_28, corrective_specialization:
> [ [ [93% of (bird, experiencer of: a good health),
> can be agent of: a flight], time: 1999],
> source: (a study, author: Foo@bird.org)] ];
>//the creator and identifier of the graph are automatically added by
>WebKB-2
>Corrective relations can only apply between assertions from different
>users. There is no need for them between definitions: a definition
>cannot be false, and whatever the concept the creator of a category has
>(implicitely) in mind, that category refers to that concept, and when
>another
>user is tempted to give another definition to that category, she actually
>thinks of another concept and hence should instead define another
>category
>(and link it to as much related categories as possible).
>If the creator of a category see that other users have misinterpreted it
>(e.g. when specializing it), she should add definitions/constraints to
>her
>category to avoid such mis-interpretations. To escape the inconsistencies
>
>that such new constraints are likely to bring to the KB, I see two
>stategies:
>- automatic resolution by "cloning": the system keeps the old version of
>the
> category (a generalization of the new version) and gives it a new
>generated
> identifier; actually, many generalizations and specializations of the
> category may have to be "cloned", so the general case is complex to
> implement, semantically sub-optimal and difficult for the users to
> understand (see www.webkb.org/doc/coopKBbuilding.html if you want to
>get
> an idea of what that approach leads to); hence, I have not adopted this
> strategy in WebKB-2;
>- the creator of the category does not (cannot) do modifications that
>lead
> to detected inconsistencies (although she can give it a more general
>name,
> more adequate to the specialization that other users have given it) but
> she specializes it (and if needed, generalizes other categories by it).
>
>This approach permits each user to enter or re-use as many categories as
>she
>wants, use the names or identifiers she wants (alternative identifiers
>may
>be introduced by connecting categories with identity links), filter out
>the
>categories or statements she does not want to see, state her beliefs
>while
>keeping the KB consistent (the FCG in the above example is not
>inconsistent
>with oc#statement_on_bird_28, but states that I believe that
>oc#statement_on_bird_28 is false) and keeps the knowledge elements as
>connected/comparable as possible and with as few redundancies as
>possible.
>Most importantly, the approach is asynchronous and the users do not have
>to
>agree, meet or even discuss with each other.
>
>For a particular application (e.g. an expert system) the categories that
>are
>not used may be filtered out, and a selection can be done on alternative
>statements (e.g. one strategy may be to select the most specialized
>statements, or to select statements according to their creator
>identifiers,
>types or even the graphs that describe those creators).
>
>To constrast with the more traditional approach, here is a quote from
>last week e-mail of John Sowa:
>> > One of the problems of a registery of ontologies (as in the
>Ontolingua
>> > server) compared to a multi-source ontology (as in WebKB) is that it
>> > is difficult for an ontology provider to relate the new categories
>(by
>> > subsumption/exclusion/identity/... links) to the categories of all
>> > other ontologies in the registry, and hence these ontologies are
>> > difficult to compare and re-use: each user must select various
>> > ontologies (and choose between competing ones) then complement and
>> > inter-relate their categories which is even more difficult than it
>> > would have been for the authors of the selected ontologies.
>>
>> I agree. We certainly need something more than just a registry as
>> in Ontolingua. What you have accomplished is what I was originally
>> proposing: a selection of modules, each of which was independent, but
>> each of which was related to the others by their mapping to a super-
>> hierarchy of categories that included all the categories from each of
>them.
>> ...
>> But the registry ideas should also be included: each module by itself
>> should be documented and annotated with all the information about its
>> history of development, contributors, testers, and especially all
>> significant applications.
>WebKB-2 supports the development and documentation of modules by
>permitting
>the storage of the knowledge of the modules into one or several Web files
>
>(possibly mixed with and/or indexing other document elements) and test
>them
>until they are considered "stable" (at which point, the instruction
>"no storage;" may be removed from the file and its knowledge
>representations
>will be committed into the KB; this is the procedure advocated by the
>documentation of WebKB-2: www.webkb.org/doc/generalDoc.html).
>
>
>
>I now introduce the initial Multi-Source Ontology (MSO) of WebKB-2 (the
>one
>currently browsable and updatable at www.webkb.org).
>I consider all categories of all existing ontologies as having some
>value,
>and being either identical or complementary. However, for time-related
>pratical
>reasons, the MSO of WebKB-2 is currently only composed of an extension
>and
>correction of the noun-related part of WordNet plus various top-level
>ontologies (mainly, extensions of those of John Sowa in his 1984/2000
>books,
>DOLCE, and various categories from other sources). Its goal/rationale is
>(like FCG) to support and ease the direct representation of English
>sentences.
>Whenever possible, I also avoided to break links from WordNet. Details
>about
>how I re-used and corrected WordNet, and merged its top-level ontology
>into
>Sowa's ontologies and DOLCE, are accessible from
>www.webkb.org/doc/papers/iccs03/ (each correction is documented and the
>ontology is avaible in FS and, for less recent versions, also in CGIF,
>RDF/DAML+OIL and WordNet formats).
>The top-level ontology is composed of about 150 primitive relation types
>(spatial/temporal/thematic/argumentative/... relations), about 30
>high-level
>concept types needed for the signatures of these relations, and about
>120 other top-level concept types (not including any WordNet type) that
>I thought interesting.
>Some general statements are associated to some high-level types
>(including WordNet ones) to describe prototypical relations from those
>types and their specializations. E.g. see www.webkb.org/kb/schemas.html
>They permit WebKB-2 to ease and normalize knowledge entering/querying by
>generating cascading content-oriented menus for any category selected by
>the user. However, many more "general statements" need to be entered to
>make this approach really helpful.
>
>Many extensions to that work would be interesting and I plan some of them
>for the short to medium term: integrating WordNet 2.0 in full, extending
>the parsing/display of other notations (RDF+OWL, KIF, CGIF),
>(beginning to) write a natural language parser for English.
>The release of WebKB-2 as open source may also be a short to medium goal.
>
>Interests from the SUO group would certainly guide or prioritize my
>goals:
>I offer to extend and develop WebKB-2 and its ontology as an ongoing
>project
>for the SUO.
>
>References:
>WebKB-2 general doc: www.webkb.org/doc/generalDoc.html
>WebKB-2 full interface: www.webkb.org/webkbShared.html
>WebKB-2 example files: www.webkb.org/kb/
>WebKB-2 languages: www.webkb.org/doc/grammars/ and
> www.webkb.org/doc/papers/iccs02/
>WebKB-2 ontology: www.webkb.org/doc/papers/iccs03/
>WebKB-2 and the Semantic Web: www.webkb.org/doc/papers/wi02/
>WebKB-1 and WebKB-2 home page: www.webkb.org
>
>
>Philippe MARTIN
>
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--
================================
Stefano Borgo
Laboratory for Applied Ontology, ISTC-CNR
via Solteri 38
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fax: +39 0461 435344
email: borgo at loa-cnr.it
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