WordNet

	Week 3 KAN Min-Yen
	(Self-study module)

Thesauri and Lexical Relations

	Polysemy: Same word, different senses of meaning
		We say that homographs are polysemous
		Slightly different concepts expressed similarly
	Synonyms: Different words, related senses of meanings
		Different ways to express similar concepts

WordNet

	Can be downloaded for free:
		www.cogsci.princeton.edu/~wn/
		Or try the online lookup at: www.cogsci.princeton.edu/cgi-bin/webwn
		We only cover up to version 1.7 here
	Emphasizes the (hierarchical) organization rather than its coverage
	Organizes hierarchy around a synset
		i.e., synonym set -- a group of tokens that can express the same core concept
		e.g., (synset #07754049) spring, fountain, outflow, outpouring, natural spring

Hypernyms from WordNet

	spring, fountain, outflow, outpouring, natural spring
	=> geological formation, geology, formation
	=> natural object
	=> object, physical object
	=> entity, physical thing
	mountain, mount
	=> natural elevation, elevation
	=> geological formation, geology, formation
	=> natural object
	=> object, physical object
	=> entity, physical thing

Structure of WordNet

Structure of WordNet

Structure of WordNet

To think about:

	Most IR research has primarily looked at statistical approaches to find “aboutness”
	How has (or might) WordNet be used to provide more functionality in searching?