Predefined thesaurus relations
The Net Search Extender contains predefined relations which include associative relations, synonym relations, and hierarchical relations.
- Associative relations
An associative relation is a bidirectional relation between two terms that do not express the same concept but relate to each other.
Predefined associative relation:
RELATED_TO
Examples:tennis RELATED_TO racket football RELATED_TO goal (sports)
- Synonym relations
A synonym relation is a bidirectional relation between two terms that have the same or similar meaning and can be used as alternatives for each other. This relation can, for example, be used between a term and its abbreviation.
Predefined synonym relation:
SYNONYM_OF
Examples:spot SYNONYM_OF stain US SYNONYM_OF United States
The figure in Figure 1 shows two
goal
terms in the same thesaurus. One is specified with the comment(sports)
, the other with the comment(abstract)
. Even if terms have the same spelling, synonym relations can connect different word groups. You can model this by using different relations when defining the thesaurus. - Hierarchical relations
A hierarchical relation is a unidirectional relation between two terms, one of which has a broader (more global) meaning than the other. Depending on its direction, the relation can be used to look up either more specialized or more global terms.
Predefined hierarchical relations:LOWER_THAN
to model narrowing relationsLOWER_THAN
relations are for modelling a sequence of more specialized terms. The deeper you follow a narrowing relation, the more specific the terms become. For example, if you look up the termball game
along aLOWER_THAN
relation, the result could besquash tennis
and so on, in a list of increasingly specialized terms.HIGHER_THAN
to model broadening relationsHIGHER_THAN
relations are for modelling a sequence of more and more global terms. The deeper you follow such a relation, the less specific the terms become. For example, if you look up the termball game
along aHIGHER_THAN
relation, the result could begame
and so on, in a list of increasingly global terms.