Hyponymy

In linguistics, a hyponym is a word or phrase whose semantic field is included within that of another word, its hypernym (sometimes spelled hyperonym outside of the natural language processing community^{[citation needed]}). In simpler terms, a hyponym shares a type-of relationship with its hypernym. For example, scarlet, vermilion, carmine, and crimson are all hyponyms of red (their hypernym), which is, in turn, a hyponym of colour.

Computer science often terms this relationship an "is-a" relationship. For example, the phrase Red is-a colour can be used to describe the hyponymic relationship between red and colour.

Hypernymy is the semantic relation in which one word is the hypernym of another. Hypernymy, the relation in which words stand when their extensions stand in the relation of class to subclass, should not be confused with holonymy, which is the relation in which words stand when the things that they denote stand in the relation of whole to part. A similar warning applies to hyponymy and meronymy.

As a hypernym can be understood as a more general word than its hyponym, the relation is used in semantic compression by generalization to reduce a level of specialization.

Automatically finding hypernyms

Hypernym/hyponym pairs can be found in text corpora by looking for certain syntactic patterns. One of the first suggestions on how to find hypernym/hyponym pairs in a text came from Marti Hearst, who suggested looking at the output of a parser and taking all of the terms linked by constructions such as X and other Y; X could be considered a possible hyponym of Y. This method was extended by Snow et al., who developed an automated method of finding possible constructions that could signal such a pair.

Their process works by taking hypernym/hyponym pairs from WordNet and finding many noun-noun pairs from a parsed corpus. They train a classifier to select those pairs of words that have a high probability of being hypernym pairs given the constructions which link the terms in the corpus.

Wikipedia has been used as a corpus for hyponymy relation acquisition.

References

• Snow, Rion; Daniel Jurafsky; Andrew Y. Ng (2004). "Learning syntactic patterns for automatic hypernym discovery" (PDF). Advances in Neural Information Processing Systems 17. http://www.stanford.edu/~jurafsky/paper887.pdf. 
• M. Hearst (1992). "Automatic acquisition of hyponyms from large text corpora". Proceedings of 14th International Conference on Computational Linguistics 2: 539. doi:10.3115/992133.992154. 

See also

• Contrast set
• Is-a
• Meronymy
• -onym
• Subcategory
• Synonym
• Taxonomy
• WordNet (a semantic lexicon for the English language, which puts words in semantic relations to each other, mainly by using the concepts hypernym and hyponym.)
• Umbrella term

External links

• hypernym @ Everything2