Jan Pettersen Nytun, UIA
Exercises on knowledge representation – RDF, etc.
A) What is meant by an upper ontology?
Proposed answer:
Anupper ontology(top-level ontology) is an ontologywhich describes very general concepts that are the same across alldomain ontologies.
Domain ontologies implicitly or explicitly assume a higher-level ontology that it can fit into. A standard top-level ontology should help in connecting ontologies together.
(Designing a top-level ontology is difficult. It probably will not satisfy everyone who must use one. There always seem to be some problematic cases. In particular, boundary cases are often not well specified.)
B) Associationist theories define the meaning of an object in terms of a network of associations with objects – give an example and explain the example?
Proposed solution:
C) What is meant by: “Unfortunately, the Web was built for human consumption, not for machine consumption – although everything on the Web is machine-readable, it is not machine-understandable”?
Proposed solution:
While the Web was initially built predominantly for human consumption, web content is increasingly consumed by machines. An html-page (together with CSS) defines the graphical layout of data, but what the data is about is not stated. Adding metadata (data about the data) about the page content allows software to more easily search for information on the page and reason about the content.
D) What is meant by taxonomy?
Proposed solution:
Classes may be organised into a superclass-subclass hierarchy, which is also known as a taxonomy.
E) What is meant by the following statement: The Semantic Web is an extension of the current web.
Proposed solution:
F) The figure below describes an OWL ontology for representing information about courses.
Some additional information:
· Course is an owl:Class
· IKT413 and IKT507 are owl:NamedIndividual
· "Learning Systems" is a data value of type xsd:string (i.e., the way to write it in a triple is "Learning Systems"^^xsd:string).
Represent the information above as Turtle triples. Assume that the following prefixes have already been stated:
@prefix : <http://www.semanticweb.org/exam/ontologies/2014/courses#> .
@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix xml: <http://www.w3.org/XML/1998/namespace> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
Proposed solution:
G) Extend the ontology of point F with information about teachers (a teacher have a name) lecturing the courses given. Show it graphically as is demonstrated in point e.
Proposed solution: