test prep-LEC.L21 Flashcards
(17 cards)
What is the difference between the Web of Documents and the Web of Data?
The Web of Documents is for human reading (search by words), while the Web of Data is for machine understanding (search based on entities and relationships).
What is a Knowledge Graph?
A Knowledge Graph represents knowledge as a set of relationships between things, where resources are nodes and relationships are links.
What are the characteristics of a Knowledge Graph?
Scaling, Agreement, Structure, Plurality, and Asymmetry.
What is RDF?
RDF (Resource Description Framework) is a standard language to represent knowledge graphs using triples: subject, predicate, object.
What are RDF triples?
Triples consist of a subject, predicate, and object, where the subject and predicate are resources defined by IRI, and the object is either a resource or a literal.
What are some RDF serialization formats?
RDF/XML, N-triples, Turtle, JSON-LD, RDF-a.
What are blank nodes in RDF?
Blank nodes are unnamed nodes used when an entity does not need to be globally identified with an IRI.
What are the limitations of RDF?
RDF lacks restrictions on term usage, making interpretation and automation difficult.
What is RDFS?
RDFS (RDF Schema) extends RDF by defining vocabularies, relationships, and hierarchies.
What are key RDFS classes?
rdfs:Class, rdfs:Resource, rdfs:Literal, rdfs:Property, rdfs:Datatype.
What are key RDFS properties?
rdfs:subClassOf, rdfs:subPropertyOf, rdfs:domain, rdfs:range.
What is SKOS?
SKOS (Simple Knowledge Organization System) is an RDF vocabulary used for structuring knowledge systems like thesauri and taxonomies.
What are the key SKOS relationships?
skos:broader, skos:narrower, skos:broaderTransitive, skos:narrowerTransitive, skos:related.
What is the difference between skos:broader and skos:broaderTransitive?
skos:broader defines direct hierarchical relationships, while skos:broaderTransitive allows for inferred hierarchical relationships.
What are SKOS reasoning capabilities?
Check consistency, Trivial entailments, and Transitivity.
What are disjoint properties in SKOS?
skos:related is disjoint with both skos:broader and skos:narrower, meaning they cannot exist together in a valid SKOS structure.
What are some limitations of RDFS?
Cannot enforce localized constraints, existence/cardinality constraints, or transitivity/inverse/symmetry relationships.
