Ontology a Practical Guide
- author: @adam-pease
Chapter 2
- concerned with knowledge representation languages that allow for deduction.
- schema are low-expressivity and low-formality, e.g. relational database, XML
- taxonomy are in the middle, e.g. RDF/S, UML, OWL
- Logical Theory are high, e.g. Knowledge Interchange Format and Tptp are the most expressive and most formal
- "every software system has an ontology", it maybe just isn't made explicit
- "semantic networks" is one of the earliest Knowledge Representation
- Object Orientation combine procedural specification with a small amount of declarative (e.g., classes, instances, class-subclass relations), i.e., the barest minimum
- Frame languages lack a facility for expressing rules
- Description Logic
First Order Logic in SUO-KIF
- no embedded formulas/propositions (only in higher-order logics)
Ontology Development Pitfalls
- Confusing Instance and Subclass
- Part-of vs. Subclass
Modeling Events as Relations
- don't do (eats Bill HamSandwich);
- presumably, model events as things unto themselves
- "Davisonian event representation" looks a lot like what I was planning to do with hypergraphs
- most languages that have some use in inference, like OWL, don't allow statements as arguments to relations, because it's extremely difficult to reason with.
Example
{
"@id": "ex:Brutus-stabbed-Caesar",
"@type": "ont.occurence.
}
- another reason to do kebab or snake case... preservation of capitalization (if you wanna go that route)
Ontological Promiscuity / Confusing Language and Concepts
- terms need to be well-defined
Modelling Roles as Classes
- yay, typedb
Modal vs Normative
- can, may, should != obliged to, allowed to
Chapter 2 Exercises
An elephant is a mammal
(forall (?X) (=> (instance ?X Elephant) (instance ?X Mammal)))
Bob Likes Sue
(likes Bob Sue)
Koko is a gorilla
(instance Koko Gorilla)
Every farmer like a horse
(forall (?X) (=> (instance ?X Farmer) (exists (?Y) (and (likes ?X ?Y) (instance ?Y Horse)))))
Chapter 3: Ontologies (in the broadest sense)
- DOLCE universals are only employed in the service of describing particulars
- SUMO is an ontology of both particulars and universals
- SUMO has a hierarchy of properties as well as classes
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