Relations in a concept hierarchy

 

Terms in a domain do not only share the area of use but are also related to each other in one way or another. In fact, Lehmann (1996) argues that though some people find about 50 classes of relations between terms, less than 50 relations are needed to define the semantic net of a terminology.

Two basic classes of relations can be distinguished:

• Coordinating relations: (partial-) synonyms and antonyms (see 2.3.3.5);
• Subordinating relations: ISA-relation, PARTOF-relation, HASPROP-relation, TYPEOF-relation, CLASSOF-relation, etc. Most frequently used are the ISA- and PARTOF-relations as the most basic and generic relations. For convenience these are not subdivided, which would be possible otherwise.

ISA-relation   in terminology are called generic relations.  According to Van Eynde (1999, forthcoming), they cover a wide range of categories which are used in other frameworks, such as inheritance,  implication and inclusion. It is the most frequent relation resulting from subdividing concepts, called taxonomies  in lexcical semantics (Cruse, 1986, see). If every x is a y, or if every x is a type of y, the relation of x and y is an ISA-relation. Example: A compound is a word (EAGLET, 1997-99, see). HASPROP-relations   are closely related to ISA-relations, stating that x has the properties of y. This relation rarely appears in terminologies. PARTOF-relations   are often called mereonomies,  a parts-pieces relation. There are also superordinates and subordinates: The part is superordinate to the piece. Mereonymic relations can be classified as x is part of y. Example: Compounding is part of word formation (EAGLET, 1997-99, see).

Thorsten Trippel
Fri May 21 13:04:11 MET DST 1999