Plan
Introduction
Readable, Expressive and Normalising Notations
Readable, expressive and normalising textual notations are necessary for
visualising, browsing and editing realistic amount of knowledge.
Graphic interfaces are a good complement but visualising a small amount of knowledge.
Most formal notations (KIF, RDF, ...) are not readable, expressive and normalising.
Proposed general notations: Frame-CG and Formalised-English are improvements on CGs.
Proposed restricted notation: FL (the only notation that most users will need to see)
En: Any human_body is a body and has at most 2 arms, 2 legs and 1 head.
Any arm, leg and head belongs to at most 1 human body.
Male_body and female_body are exclusive subtypes of human_body
and so are juvenile_body and adult_body.
FL: human_body < body,
part: arm [0..1,0..2] head [1,1],
> {male_body female_body} {juvenile_body adult_body};
KIF: (forall ((?b human_body)) (body ?b))
(forall ((?b human_body)) (atMostN 2 '?a arm (part ?b '?a)))
(forall ((?a arm)) (atMostN 1 '?b human_body (part '?b ?a)))
(forall ((?b male_body)) (and (human_body) (not (female_body ?b))))
...
The full translation in KIF of the 3 lines in FL:
(forall ((?b human_body)) (body ?b))
(forall ((?b human_body)) (atMostN 2 '?a arm (part ?b '?a)))
(forall ((?a arm)) (atMostN 1 '?b human_body (part '?b ?a)))
(forall ((?b human_body)) (atMostN 2 '?a leg (part ?b '?a)))
(forall ((?a head)) (atMostN 1 '?b human_body (part '?b ?a)))
(forall ((?b male_body)) (and (human_body) (not (female_body ?b))))
(forall ((?b female_body)) (and (human_body) (not (male_body ?b))))
(forall ((?b male_body)) (and (human_body) (not (female_body ?b))))
(forall ((?b juvenile_body)) (and (human_body) (not (adult_body ?b))))
(forall ((?b adult_body)) (and (human_body) (not (juvenile_body ?b))))
(defrelation atMostN (?num ?var ?type ?predicate) :=
(exists ((?s set)(?n)) (and (size ?s ?n) (=< ?n ?num)
(truth ^(forall (,?var) (=> (member ,?var ,?s)
(and (,?type ,?var) ,?predicate)))))))
The full translation in RDF+OWL of the 3 lines in FL:
Readable, Expressive and Normalising Notations
FL can also be used for structured discussions.
"XML is useless for knowledge representation, exchange or storage"
argument: ("using XML tools for KBSs is a useless additional task"
argument: "KBSs do not use XML internally" (pm,
objection: "XML can be used for knowledge exchange or storage" (fg,
objection: "it is as easy to use other formats for
knowledge exchange or storage" (pm),
objection: "a KBS (also) has to use other formats for
knowledge exchange or storage" (pm)))
)(pm);
Querying
Category querying
WebKB permits to find categories (type or instance) according to
their names, creators, relations connected to them, and permits to display all
the objects (categories and statements) directly or indirectly connected to them
on a single screen.
Most other tools impose much more browsing to access information and hence make it
difficult to retrieve and compare information in any realistic amount of knowledge.
Category comparison
WebKB permits to find what relations exist between two given categories
(this feature is sometimes useful but not so common).
Statement querying FCG (instead of FL) can be used to express and retrieve statements that are more complex than relations between categories. Various search operators are provided: "spec", "gen", "?" (a combinaison of "spec" and "gen"), etc.
? [a person, agent of: a sell] [Ned, agent of: (a sell, object: a car)](pm, 21/2/2001); [3 cars, object of: (2 sells, agent: Ned, time: 21/1/2001)](pm,12/7/2005); [John, believer of: not [Ned, agent of: a sell]](jj,3/12/2004);
Comparing
An original feature: a "scalable" way to compare a set of objects. (See the article).
compare pm#WebKB-2 km#Ontolingua on
(support of: a is#IR_task, output_language: a km#KR_notation,
part: a is#user_interface), maxdepth 5
WebKB-2 Ontolingua
support of:
is#IR_task + +
is#lexical_search + +
is#regular_expression_based_search + .
km#knowledge_retrieval_task + .
km#generalization_structural_retrieval + .
...
output_language:
km#KR_notation + +
(expressivity: km#FOL) + +
km#FCG + .
km#KIF . +
km#XML-based notation + .
km#RDF + -
...
Supporting Cooperation Between Knowledge Providers
Each category, relation and statement has a creator ->
- any identifier is prefixed by its creator identifier to avoid lexical conflict;
- knowledge filtering can be done on the creator.
Furthermore:
- relations such as corrective_restriction, correction
more_concise_reformulation must be used when redundancies or
inconsistencies are detected; this solves semantic conflicts, encourage knowledge
sharing and permit later automatic knowledge filtering;
- argumentations relations between statements and votes on statements permit to valuate
the originality and usefulness of each statement and each statement creator, thus
easing the filtering of uninteresting statements and encouraging authors to be precise
and original.
Ontologies
Merge/alignment of various
top-level ontologies, e.g. from
Sowa,
Dolce, the
SUMO, the
Lifecycle Integration Schema, the
Natural Semantic Metalanguage,
OWL,
DAML+OIL,
KIF and the
Dublin Core.
The result (the Multi-Source Ontology,
which anyone can extend via WebKB-2) was
voted by the
Standard Upper Ontology Working Group as a material to work on.
Transformation of WordNet 1.7 into a genuine lexical ontology (connecting 120,000 English nouns to 90,000 categories related by the words of a language to the categories representing the main meaning of these words, and connects these categories via conceptual links: unlike in foundational ontologies, no more complex definitions are generally provided; however, for important categories such as the top-level ones and the often used ones, "schemas" representing the relations that are commonly used from instances of these)
Beginning of the representation of Knowledge Management Resources (data structures, techniques, tools, ...), first focusing on CG-related resources (e.g., classification of 7 CG tools according to 160 features). After extensions, this is intended to be the core of a state of the art in ontology engineering that will be cooperatively updatable by researchers in this domain and according to the above cited protocols.
Conclusion