WordNet Database Contents Limitations Related Projects

It groups English words into sets of synonyms called synsets, provides short definitions, and records the various semantic relations between these synonym sets. The purpose is twofold: to produce a combination of dictionary and thesaurus that is more intuitively usable, and to support automatic text analysis and artificial intelligence applications. The database and software tools have been released under a BSD style licence and can be downloaded and used freely. The database can also be browsed online.

WordNet was created and is being maintained at the Cognitive Science Laboratory of Princeton University under the direction of psychology professor George A. Miller. Development began in 1985. Over the years, the project received about $3 million of funding, mainly from government agencies interested in machine translation.

1 Database contents

As of 2003, the database contains about 140,000 words organized in over 110,000 synsets for a total of 195,000 word-sense pairs; in compressed form, it is about 12 megabytes large.

WordNet distinguishes between nouns, verbs, adjectives and adverbs on the assumption that these are stored differently in the human brain. Every synset contains a group of synonymous words or collocations (a collocation is a sequence of words that go together to form a specific meaning, such as "car pool"); words typically participate in several synsets. The meaning of the synsets is further clarified with short definining glosses. A typical example synset with gloss is

Every synset is connected to other synsets via a number of relations. These relation vary based on the type of word:

WordNet also provides the polysemy count of a word: the number of synsets that contain the word. If a word participates in several synsets (i.e. has several senses), then typically some senses are much more common than others. WordNet quantifies this by the frequency score: in several sample texts all words were semantically tagged with the corresponding synset, and then it was counted how often a word appeared in a specific sense.

The database's interface is able to deduce the root form of a word from the user's input; only the root form is stored in the database.

2 Limitations

Unlike other dictionaries, WordNet does not include information about etymologyEtymology is the study of the origins of words. Some words have been derived from other languages, possibly in a changed form (the source words are called etymons . Through old texts and comparisons with other languages, etymologists try to reconstruct th, pronunciation and the forms of irregular verbs and contains only limited information about usage.

The actual lexicographical and semantical information is maintained in lexicographer files, which are then processed by a tool called grind to produce the distributed database. Both grind and the lexicographer files are freely available, but modifying and maintaining the database is nonetheless difficult.

3 Related projects

The project EuroWordNetEuroWordNet is a system of semantic networks for European languages. Each language develops its own wordnet; these are interconnected with interlingual links (ILI). See also WordNet External links http://www. nl/EuroWordNet/ Computational linguistics. has produced WordNets for several European languages and linked them together; these are not freely available however. The Global Wordnet project attempts to coordinate the production and linking of wordnets for all languages. The publishers of the Oxford English DictionaryThe Oxford English Dictionary (OED is a comprehensive multi-volume dictionary published by the Oxford University Press. Generally regarded as the definitive dictionary of Modern English, it defines around 500,000 headwords and includes some 2. 5 million i have voiced plans to produce their own online WordNet.

The eXtended WordNet is a project at the University of Texas at Dallas which aims to improve WordNet by semantically parsing the glosses, thus making the information contained in these definitions available for automatic knowledge processing systems. It is also freely available under a license similar to WordNet's.

The GCIDEGCIDE is the GNU version of the Collaborative International Dictionary of English. The dictionary was derived from the Webster's Revised Unabridged Dictionary Version published 1913 and WordNet. The GNU version is licensed under the GNU General Public Lic project produces a dictionary by combining a public domainThe public domain comprises the body of all creative works and other knowledge—writing, artwork, music, science, inventions, and others—in which no person or organization has any proprietary interest. Proprietary interest is typically represented by a cop Webster's Dictionary1888 advertisment for Webster's Dictionary Webster's Dictionary is an American English language dictionary initially published by Noah Webster in 1806. The phrase Webster's has become a genericized trademark for dictionaries. The modern Merriam-Webster di from 1913 with some WordNet definitions and material provided by volunteers. It is released under the copyleftit has no recognized legal meaning. Copyleft describes a group of licenses applied to works such as software, documents, and art. Where copyright law is seen by the original proponents of copyleft as a way to restrict the right to make and redistribute co license GPL.

The hypernym/hyponym relationships among the noun synsets can be used as an ontology in the computer science sense. The SUMO upper ontology has produced a mapping from the WordNet synsets for nouns and verbs to SUMO classes. The OpenCyc upper ontology is also linked to WordNet. WordNet was the primary source for constructing the lower classes of the SENSUS ontology.

4 See also:

5 External links:

The WordNet Home Page
Global Wordnet
eXtended WordNet
Article about Miller and WordNet in the Star Ledger, January 22, 2002
A nice implementation of WordNet and Wikipedia
A RDF representation of WordNet
Hindi WordNet(हिंदी शब्दतंत्र)
Marathi WordNet(मराठी शाब्दबंध)
WordNet Chat Developer's Forum -- Discussion forum for application developers that use WordNet.

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