Manchester Presentations

1. Terminologies

• Constrained vocabularies
   
• Limited domain
   
• Dublin core
   
• Hierarchical coding scheme
   
  • Okay for humans
     
  • Single relationship
     

Description Logics

• Explicit semantics
   
• Allow partitive relationships
  get references from Sean
  
   
• Process
   
  • If things related
     
  • Shows inconsistencies
    eg define car as having 4 wheels then try to model Reliant Robin
    
     
• Multiple inheritance
   
• Finds
   
  • Missing subsumption relationships
    Galen, GONG
    
     

Reasoning

• Axioms
  definitions to establish inter-ontology relationships
  
   

Mad-cows

• Classes
   
  • Animal
    has-class eats thing (some)
    
     

Axioms

• Subclass
  old lady: has pet cat and has pet some animal

  therefore, old lady is subclass of cat owner

  
   
• Disjoint
  dog|cat
  
   

3. OilEd

• SubclassOf
  one-way is-a
  
   
• SameClassAs
  is-a in both directions; necessary and sufficient

  
  

  
   
• Properties
  property can have super properties, eg has_pet suibsumed under likes
  
   
• Domain/Range
  domain on left of relationship, range on right
  
   
• Restrictions
   
  • To-class
    only

    universal - but (true if empty)

    
     
  • Has-class
    some, at least 1

    existential

    
     
• Reasoner
   
  • Rearrange structure
     
  • Find problems
     
• Doesn't check namespaces
   
  • No other tools yet
     

2. OIL

underpinned with semantics

• XOL
   
  • Frame base
    not clear what the semantics are
    
     
    • Superclass
       
    • Properties
       
    • Assertive
       
• OntoKnowledge
   
• DAML
   
• Semantic Web
   
  • Metadata
    speak the same language
    
     
  • Terminologies
    means the same thing
    
     
  • Ontologies
    domain understanding
    
     
• Frames vs Logic
   
  • Frames
     
  • Logic
     
    • DLs
       
      • Predicates
         
      • Binary relatinships
         
• Extends Frame Languages
   
  • Classes
     
    • Primitive
       
    • Defined
      two-way implication
      
       
    • Slot constraint
      eats has-value meat (eats some meat)

      eats value-type meat (eats only meat)

      
       
      • Properties
        can be declared as transitive
        
         

Inference engine

Reasoner: theorem prover

• Ask questions
   
  • OilEd
    asks questions to check correctness
    
     
• Tools on top
  need to encode questions
  
   

Please send your comments to Tony Linde. This document was updated 15-Aug-2002.