Week3-1Semantic similarity:Synonymy and other Semantic Relations

Synonyms and paraphrases

Synonym

• Different words(also word compounds) can have similar meanings.
• True synonyms are actually relatively rare.

Polysemy

Polysemy is the property of words to have multiple senses.

• Book

  • literary work
  • stack of pages
  • record of business transactions
  • ……

• The same word can also have multiple POS, each with its own set of senses

• The different senses don’t have to be equally different
• Some of the senses may overlap
• Some words can be highly polysemous(“get”)

Other semantic relations

• Antonymy(near opposite, raise-lower)
• Hypernymy(more general concept, deer is the hypernymy of elk)
• Hyponymy(more specific concept, elk is the hyponymy of deer)
• Membership meronymy(a flock includes sheep(or birds))
• Part meronymy(a table has legs)

Semantic relations hold between word senses, not words themselves.

Hot synonymy warm(temperature), spicy

Synset

Used to group together all synonyms of the same word. If a word is polysemous, it may be associated with multiple synsets

Word Net

Remark: word net is more forest like, rather than tree like, because it has many roots(entity, abstraction, ……).