Comments on ODM Revised Submission dated 10 January 2005

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Comments on ODM Revised Submission dated 10
January 2005

• He Keqing, OKABE, Masao
• Project editor
• MMF Ontology Registration
• ISO/IEC JTC1 SC32/WG2
• 2005.02.03

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About this document

• All the comments in this document are prepared by
  all the active members of ISO/IEC JTC1 SC32/WG2
  MMF Ontology Registration Project.
  
• Japan
• Hajime Horiuchi (UMTP, Tokyo International
  Univ.)
  
• Masao Okabe (Project editor, UMTP, TEPCO)
• Masaharu Obayashi (UMTP, K-three)
• China
• He Keqing (Project editor, SKLSE, Wuhan Univ.)
• He Yangfan (SKLSE, Wuhan Univ.)
• Wang Chong (SKLSE, Wuhan Univ.)
• Korea
• Doo-Kwon Baik (Korea Univ.)
• Sam Oh (Sungkyunkwan Univ.)
• Unfortunately, we did not have enough time to
  review it thoroughly and briefly reviewed only
  the metamodels of SCL, DL and RDFS/OWL.
  
• So, the comments are only on them and not
  comprehensive.

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Our basic understanding of ODM

• Each ODM metamodel can store the ontology
  described in the corresponding ontology
  description language,
  
• without any loss of information,
• For example, a famous owl ontology owl.xml at
  can be stored in OWL ODM metamodel without any
  loss of information.
  
• in proper granularitylevel so that the mapping
  between them can be defined in terms of the
  meteclasses of the metamodels as much as
  possible.

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Common basic structure of ontology

• Very roughly speaking, ontology has the following
  structure.

• Example
• An ontology Example consists of the following
  two sentences.
  
• MotherParent?Female
• Mother(Susan)
• These two sentences consists of the 4 following
  non-logical symbols (and logical symbols)
  
• Non-logical symbol
• Mother, Parent, Female, Susan
• Logical symbol
• , ? , (, )

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Three different policies on metamodeling in ODM
SCL
1.
Explicitly have metaclasses for logical symbol
s?
No
DL
Yes
Metaclasses for sentences and symbols are expl
icitly
distinguished?
Yes
2.
No
3.
OWL

• General Comment
• There should be only one policy in ODM
  metamodels, preferably 1.

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About SCL Metamodel

• Metaclass for an ontology
• SCLModule
• SCL Module has a composition association with SCL
  Text.
  
• SCL Text has a composition association with
  Sentence.
  
• Metaclass for a sentence
• Sentence
• Sentence has a composition association with
  Term.
  
• Sentence has several subclasses corresponding to
  the one that some logical symbol is applied
  for.
  
• e.g. Conjunction, Implication, Negation etc.
• Metaclass for a non-logical symbol
• Logical Name
• Logical Name is a subclass of Term.
• Metaclass for a logical symbol
• --- none ---

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About DL Metamodel (1)

• Metaclass for an ontology
• Tbox (and Abox?)
• TBox has an association named containment with
  Term.
  
• i.e. TBox contains Term.
• B.2.1 says Term is the terminology contained in
  this TBox.
  
• So, it is different from B.6.1 Term, which is a
  component used to build expressions.
  
• Comment1
• This association is not a composition
  association.
  
• It is better to be a composition.
• Comment2
• DL handbook says, in DL, terminology and Tbox has
  the exactly same meaning, that is, a set of
  definitions (of atomic concepts).
  
• So, the description of Term at B.2.1 is strange.
• Term should be Expression ( or Sentence
  )defined at B.6.2
  
• Comment3
• It seems strange that Abox is a subclass of Tbox
  and that Instance is a subclass of Term.
  

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About DL Metamodel (2)

• Metaclass for a sentence
• Expression
• Expression has a composition association with
  Term.
  
• Expression also has a composition association
  with Constructor(i.e. logical symbol)
  
• Expression does not have subclasses corresponding
  to the one that some logical symbol is applied
  for.
  
• Comment4
• Expression should have subclasses corresponding
  to the one that some logical symbol is applied
  for so that it can be accommodated to the same
  metamodeling policy as SCL.
• also see comment 7 and SCL Metamodel and DL
  Metamodel at slide 10
  
• Comment5
• It is better to have subclass sentence
  explicitly because an expression is not always a
  sentence.
  
• red one is related to the general comment.

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About DL Metamodel (3)

• Metaclass for a non-logical symbol
• Element
• Element has two subclasses Concept and Role.
• Comment6
• The naming of Element is confusing because it
  sounds like an element of TBox and ABox.
  Predicate is better.
  
• Metaclass for a logical symbol
• Constructor
• Constructor has several subclasses such as
  Intersection, Implication, Negation etc.
  
• Comment7
• Constructor is not necessary if Expression have
  subclasses corresponding to the one that some
  logical symbol is applied for explicitly.
  
• also see comment 3 and SCL Metamodel and DL
  Metamodel at slide 10
  

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SCL Metamodel and DL Metamodel

• SCL Metamodel Figure25 Sentences
• DL Metamodel Figure 59 Specializations of
  Constructor (extract)

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About RDFS/OWL Metamodel(1)

• Metaclass for an ontology
• RDFDescription
• 11.7.1 says A description consists of the
  various classes and properties that can be used
  to describe and represent a domain of
  knowledge.
• Comment8
• Usually describes annotative
  description of an ontology. What represent a
  whole ontology is
  

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About RDFS/OWL Metamodel(2)

• Metaclass for a sentence (and a non-logical
  symbol)
  
• EnumeratedClass etc.
• For example, EnumeretedClass can be understood a
  class defined by an exhaustive enumeration of
  individuals that together form the instances of a
  class .
• However, if its associations and attributes are
  ignored, it can be understood a non-logical
  symbol because it has only name and URI.
  
• Metaclass for both a non-logical symbol (and a
  sentence)
  
• RDFSClass etc.
• For example, the metaclass RDFSClass without
  associations can be understood a non-logical
  symbol because it has only name and URI.
  
• However, RDFSClass with association subClassof
  can be understood as a sentence because it is a
  partial definition.
  

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About RDFS/OWL Metamodel(3)

• sentence if its associations are cared.
• symbol if its associations are ignored.

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About RDFS/OWL Metamodel(4)

• Comment9
• To be accommodated to the same metamodeling
  policy as SCL,
  
• metaclasses for non-logical symbols (mostly a
  metaclass only with name and URI) and metaclasses
  for sentences (mostly a metaclass with its
  associations for the definition of its concept)
  should be explicitly distinguished.
• The necessary metamodel may not be this kind of
  ODM OWL metamodel, but a metamodel corresponding
  to OWL Web Ontology Language Semantics and
  Abstract Syntax Section2. Abstract Syntax at
  http//www.w3.org/TR/owl-semantics/syntax.html,
  (hereinafter called W3C OWL Abstract Syntax).
• Note
• 19.5 ODM OWL Abstract Syntax also defines an
  abstract syntax based on ODM OWL metamodel.
  
• Superficially, it looks similar to W3C OWL
  Abstract Syntax, but actually it is substantially
  different.
  

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About RDFS/OWL Metamodel(5)

• W3C OWL Abstract Syntax (extract)
• ontology 'Ontology(' ontologyID
  directive ')'
  
• directive 'Annotation('
  ontologyPropertyID ontologyID ')'
  
• 'Annotation('
  annotationPropertyID URIreference ')'
  
• 'Annotation('
  annotationPropertyID dataLiteral ')'
  
• 'Annotation('
  annotationPropertyID individual ')'
  
• axiom
• fact
• axiom 'EnumeratedClass(' classID
  'Deprecated' annotation individualID
  ')
  
• etc.
• Note
• Here, axiom and fact are sentences.
• The class definition by enumeration is an axiom
  and it is distinguished from the class itself
  (i.e. classID, the symbol for the class)
  

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About RDFS/OWL Metamodel(6)

• ODM OWL Abstract Syntax
• ontology 'OWLOntology(' ontologyID
• 'OWLbackwardCompatibleWith(
• ontologyID ')'
• 'OWLincompatableWith(' ontologyID ')'
• 'OWLpriorVersion(' ontologyID ')'
• 'OWLimports(' ontologyID ')'
• 'contains('
• classID resrictionID
• datavaluedPropertyID
• individualvaluedPropertyID
• ontologyPropertyID
• annotationPropertyID
• dataTypeID individualID ')'
• rdfsResourceContent ')
• Note
• ontology does not contain sentences(i.e. owlClass
  etc.) but only symbols (i.e. class ID etc.)
  

• owlClass 'OWLClass(' classID
• 'complete(' Boolean(false) ')'
• 'deprecated(' Boolean(false) ')'
• 'OWLdisjointWith(' classID ')'
• 'OWLequivalentClass(' classID ')'
• 'RDFSsubClassOf(' classID
• restrictionID ')'
• rdfsResourceContent
• 'OWLClass(' anonClassID
• 'OWLoneOf(' individualID ')'
• 'OWLcomplementOf(' classID ')'
• 'OWLintersectionOf(' classID ')'
• 'OWLunionOf(' classID ')' ')'

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• Thank you for your attention.