Editing WordNet

{{Short description|Computational lexicon of English}}
{{Infobox software
| title = WordNet
| name = WordNet
| screenshot = WordNet.PNG
| screenshot size = 300px
| caption = A snapshot of WordNet's definition of itself
| author = [[George Armitage Miller]]
| developer = [[Princeton University]]
| released = mid 1980s
| latest release version = 2024 Edition
| latest release date = {{Start date and age|2024|11|1|df=yes}}<ref>{{cite web |url=https://wordnet.princeton.edu/news-0 |title=WordNet News}}</ref>
| repo = https://github.com/globalwordnet/english-wordnet
| programming language = [[Prolog]]
| operating system = Unix, Linux, Solaris, Windows
| size = 37MB (including 161,705 words organized in 120,630 synsets for a total of 418,168 word-sense pairs)
| language = More than 200 languages
| genre = [[Lexical database]]
| licence = [[BSD licenses|BSD-like]]
| website = {{URL|https://wordnet.princeton.edu/}}
{{URL|https://en-word.net/}}
}}

'''WordNet''' is a [[lexical database]] of [[semantic relation]]s between [[word]]s that links [[word]]s into [[semantic relation]]s including [[synonyms]], [[hyponyms]], and [[meronym]]s. The synonyms are grouped into ''[[synsets]]'' with short definitions and usage examples. It can thus be seen as a combination and extension of a [[dictionary]] and [[thesaurus]]. Its primary use is in automatic [[natural language processing|text analysis]] and [[artificial intelligence]] applications. It was first created in the [[English language]]<ref>G. A. Miller, R. Beckwith, C. D. Fellbaum, D. Gross, K. Miller. 1990. WordNet: An online lexical database. Int. J. Lexicograph. 3, 4, pp. 235–244.</ref> and the English WordNet [[database]] and [[software]] tools have been released under a [[BSD License|BSD style license]] and are freely available for download. The latest official release from Princeton was released in 2011.{{Citation needed|date=February 2025}} Princeton currently has no plans to release any new versions due to staffing and funding issues.<ref name=":0" /> New versions are still being released annually through the Open English WordNet website. Until about 2024{{Citation needed|date=February 2025}} an online version was previously available through wordnet.princeton.edu. That version of WordNet has been deprecated, but a new online version is available at en-word.net. There are now WordNets in more than 200 languages.<ref>{{cite web |title=WordNets in the World |url=http://globalwordnet.org/resources/wordnets-in-the-world/ |website=Global WordNet Association |access-date=19 January 2020}}</ref>

== History and team members ==
WordNet was first created in 1985, in English only, in the [[Cognitive Science]] Laboratory of [[Princeton University]] under the direction of [[psychology]] [[professor]] [[George Armitage Miller]]. It was later directed by [[Christiane Fellbaum]]. The project was initially funded by the U.S. Office of Naval Research, and later also by other U.S. government agencies including the [[DARPA]], the [[National Science Foundation]], the [[Disruptive Technology Office]] (formerly the Advanced Research and Development Activity) and REFLEX. George Miller and Christiane Fellbaum received the 2006 Antonio Zampolli Prize for their work with WordNet.

The Global WordNet Association is a non-commercial organization that provides a platform for discussing, sharing and connecting WordNets for all languages in the world. [[Christiane Fellbaum]] and [[Piek Vossen|Piek Th.J.M. Vossen]] are its co-presidents.<ref>{{cite web |title=About Global WordNet Association |url=http://globalwordnet.org/about-gwa/ |website=Global WordNet |access-date=19 January 2020}}</ref>

== Database contents ==
[[File:Hamburger WordNet.png|thumb|Example entry "Hamburger" in WordNet]]

The database contains 155,327 words organized in 175,979 [[synsets]] for a total of 207,016 word-sense pairs; in [[data compression|compressed]] form, it is about 12 [[megabyte]]s in size.<ref name=":0">{{cite web|url=http://wordnet.princeton.edu/man/wnstats.7WN.html |title=WordNet Statistics |publisher=Wordnet.princeton.edu |access-date=2018-06-22}}</ref>

It includes the lexical categories [[noun]]s, [[verb]]s, [[adjective]]s and [[adverb]]s but ignores [[preposition]]s, [[determiner (linguistics)|determiner]]s and other function words.

Words from the same lexical category that are roughly synonymous are grouped into [[synsets]], which include simplex words as well as [[collocation]]s like "eat out" and "car pool." The different senses of a [[polysemous]] word form are assigned to different synsets. A synset's meaning is further clarified with a short defining ''gloss'' and one or more usage examples. An example adjective synset is:

: good, right, ripe – (most suitable or right for a particular purpose; "a good time to plant tomatoes"; "the right time to act"; "the time is ripe for great sociological changes")

All synsets are connected by means of semantic relations. These relations, which are not all shared by all lexical categories, include:
* [[Noun]]s
**''[[hypernym]]'': ''Y'' is a hypernym of ''X'' if every ''X'' is a (kind of) ''Y'' (''canine'' is a hypernym of ''[[dog]]'')
**''[[hyponym]]'': ''Y'' is a hyponym of ''X'' if every ''Y'' is a (kind of) ''X'' (''dog'' is a hyponym of ''canine'')
**''coordinate term'': ''Y'' is a coordinate term of ''X'' if ''X'' and ''Y'' share a hypernym (''wolf'' is a coordinate term of ''dog'', and ''dog'' is a coordinate term of ''wolf'')
**''[[holonymy|holonym]]'': ''Y'' is a holonym of ''X'' if ''X'' is a part of ''Y'' (''building'' is a holonym of ''window'')
**''[[meronymy|meronym]]'': ''Y'' is a meronym of ''X'' if ''Y'' is a part of ''X'' (''window'' is a meronym of ''building'')
* [[Verb]]s
**''hypernym'': the verb ''Y'' is a hypernym of the verb ''X'' if the activity ''X'' is a (kind of) ''Y'' (''to perceive'' is an hypernym of ''to listen'')
**''[[troponym]]'': the verb ''Y'' is a troponym of the verb ''X'' if the activity ''Y'' is doing ''X'' in some manner (''to lisp'' is a troponym of ''to talk'')
**''[[entailment]]'': the verb ''Y'' is entailed by the verb ''X'' if by doing ''X'' you must be doing ''Y'' (''to sleep'' is entailed by ''to snore'')
**''coordinate term'': the verb ''Y'' is a coordinate term of the verb ''X'' if ''X'' and ''Y'' share a hypernym (''to lisp'' is a coordinate term of ''to yell'', and ''to yell'' is a coordinate term of ''to lisp'')

These semantic relations hold among all members of the linked synsets. Individual synset members (words) can also be connected with lexical relations. For example, (one sense of) the noun "director" is linked to (one sense of) the verb "direct" from which it is derived via a "morphosemantic" link.

The morphology functions of the software distributed with the database try to deduce the [[Lemma (morphology)|lemma]] or [[stem (linguistics)|stem]] form of a [[word]] from the user's input. Irregular forms are stored in a list, and looking up "ate" will return "eat," for example.

== Knowledge structure ==
Both nouns and verbs are organized into hierarchies, defined by [[hypernym]] or ''[[is-a|IS A]]'' relationships. For instance, one sense of the word ''dog'' is found following hypernym hierarchy; the words at the same level represent synset members. Each set of synonyms has a unique index.
{{tree list}}
* {{Tree list/final branch}}dog, domestic dog, Canis familiaris
** {{Tree list/final branch}}canine, canid
*** {{Tree list/final branch}}carnivore
**** {{Tree list/final branch}}placental, placental mammal, eutherian, eutherian mammal
***** {{Tree list/final branch}}mammal
****** {{Tree list/final branch}}vertebrate, craniate
******* {{Tree list/final branch}}chordate
******** {{Tree list/final branch}}animal, animate being, beast, brute, creature, fauna
********* {{Tree list/final branch}}...
{{tree list/end}}
At the top level, these hierarchies are organized into 25 beginner "trees" for nouns and 15 for verbs (called ''lexicographic files'' at a maintenance level). All are linked to a unique beginner synset, "entity".
Noun hierarchies are far deeper than verb hierarchies.

Adjectives are not organized into hierarchical trees. Instead, two "central" antonyms such as "hot" and "cold" form binary poles, while 'satellite' synonyms such as "steaming" and "chilly" connect to their respective poles via a "similarity" relations. The adjectives can be visualized in this way as "dumbbells" rather than as "trees".

== Psycholinguistic aspects ==
The initial goal of the WordNet project was to build a lexical database that would be consistent with theories of human semantic memory developed in the late 1960s. Psychological experiments indicated that speakers organized their knowledge of concepts in an economic, hierarchical fashion. Retrieval time required to access conceptual knowledge seemed to be directly related to the number of hierarchies the speaker needed to "traverse" to access the knowledge. Thus, speakers could more quickly verify that ''canaries can sing'' because a canary is a songbird, but required slightly more time to verify that ''canaries can fly'' (where they had to access the concept "bird" on the superordinate level) and even more time to verify ''canaries have skin'' (requiring look-up across multiple levels of hyponymy, up to "animal").<ref>Collins A., Quillian M. R. 1972. Experiments on Semantic Memory and Language Comprehension. In ''Cognition in Learning and Memory''. Wiley, New York.</ref>
While such [[psycholinguistics|psycholinguistic]] experiments and the underlying theories have been subject to criticism, some of WordNet's organization is consistent with experimental evidence. For example, [[anomic aphasia]] selectively affects speakers' ability to produce words from a specific semantic category, a WordNet hierarchy. Antonymous adjectives (WordNet's central adjectives in the dumbbell structure) are found to co-occur far more frequently than chance, a fact that has been found to hold for many languages.

== As a lexical ontology ==
WordNet is sometimes called an ontology, a persistent claim that its creators do not make. The hypernym/hyponym relationships among the noun synsets can be interpreted as specialization relations among conceptual categories. In other words, WordNet can be interpreted and used as a lexical [[ontology (information science)|ontology]] in the [[computer science]] sense. However, such an ontology should be corrected before being used, because it contains hundreds of basic semantic inconsistencies; for example there are, (i) common specializations for exclusive categories and (ii) redundancies in the specialization hierarchy. Furthermore, transforming WordNet into a lexical ontology usable for knowledge representation should normally also involve (i)&nbsp;distinguishing the specialization relations into ''subtypeOf'' and ''instanceOf'' relations, and (ii)&nbsp;associating intuitive unique identifiers to each category. Although such corrections and transformations have been performed and documented as part of the integration of WordNet&nbsp;1.7 into the cooperatively updatable knowledge base of WebKB-2,<ref>{{cite web|url=http://www.webkb.org/doc/wn/ |title=Integration of WordNet 1.7 in WebKB-2|publisher=Webkb.org |access-date=2014-03-11}}</ref> most projects claiming to reuse WordNet for knowledge-based applications (typically, knowledge-oriented information retrieval) simply reuse it directly.

WordNet has also been converted to a formal specification, by means of a hybrid bottom-up top-down methodology to automatically extract association relations from it and interpret these associations in terms of a set of conceptual relations, formally defined in the [[Upper ontology#DOLCE|DOLCE foundational ontology]].<ref>{{cite book |first1=A. |last1=Gangemi |first2=R. |last2=Navigli |first3=P. |last3=Velardi |url=http://www.w3.org/2001/sw/BestPractices/WNET/ODBASE-OWN.pdf |title=The OntoWordNet Project: Extension and Axiomatization of Conceptual Relations in WordNet |work= Proc. of International Conference on Ontologies, Databases and Applications of SEmantics (ODBASE 2003) |location=Catania, Sicily (Italy) |year=2003 |pages= 820–838}}</ref>

In most works that claim to have integrated WordNet into ontologies, the content of WordNet has not simply been corrected when it seemed necessary; instead, it has been heavily reinterpreted and updated whenever suitable. This was the case when, for example, the top-level ontology of WordNet was restructured<ref>{{cite conference | first1 = A. | last1 = Oltramari | first2 = A. | last2 = Gangemi | first3 = N. | last3 = Guarino | first4 = C. | last4 = Masolo | date = 2002 | title = Restructuring WordNet's Top-Level: The OntoClean approach | citeseerx = 10.1.1.19.6574 | conference = OntoLex'2 Workshop, Ontologies and Lexical Knowledge Bases (LREC 2002) | location = Las Palmas, Spain | pages = 17–26 }}</ref> according to the [[OntoClean]]-based approach, or when it was used as a primary source for constructing the lower classes of the SENSUS ontology.

== Limitations ==
The most widely discussed limitation of WordNet (and related resources like [[ImageNet]]) is that some of the [[semantic relation]]s are more suited to concrete concepts than to abstract concepts.<ref>{{cite journal |last1=Rudnicka |first1=Ewa |last2=Bond |first2=Francis |last3=Grabowski |first3=Łukasz |last4=Piasecki |first4=Maciej |last5=Piotrowski |first5=Tadeusz |title=Lexical Perspective on Wordnet to Wordnet Mapping |journal=Proceedings of the 9th Global WordNet Conference (GWC 2018) |date=2018 |page=210}}</ref> For example, it is easy to create hyponyms/hypernym relationships to capture that a "[[conifer]]" is a type of "[[tree]]", a "tree" is a type of "[[plant]]", and a "plant" is a type of "[[organism]]", but it is difficult to classify emotions like "fear" or "happiness" into equally deep and well-defined hyponyms/hypernym relationships.

Many of the concepts in WordNet are specific to certain languages and the most accurate reported mapping between languages is 94%.<ref>{{cite journal |last1=Bond |first1=Francis |last2=Foster |first2=Ryan |title=Linking and Extending an Open Multilingual Wordnet |journal=Proceedings of the 51st Annual Meeting of the Association for Computational Linguistics |date=2013 |pages=1352–1362 |url=https://www.aclweb.org/anthology/P13-1133.pdf |access-date=20 January 2020}}</ref> Synonyms, hyponyms, meronyms, and antonyms occur in all languages with a WordNet so far, but other semantic relationships are language-specific.<ref>{{cite journal |last1=Fellbaum |first1=Christiane |last2=Vossen |first2=Piek |title=Challenges for a multilingual wordnet |journal=Language Resources and Evaluation |date=2012 |volume=46 |issue=2 |pages=313–326|doi=10.1007/s10579-012-9186-z |s2cid=10117946 }}</ref> This limits the interoperability across languages. However, it also makes WordNet a resource for highlighting and studying the differences between languages, so it is not necessarily a limitation for all use cases.

WordNet does not include information about the [[etymology]] or the pronunciation of words and it contains only limited information about usage. WordNet aims to cover most everyday words and does not include much domain-specific terminology.

WordNet is the most commonly used computational lexicon of English for [[word-sense disambiguation]] (WSD), a task aimed at assigning the context-appropriate meanings (i.e. synset members) to words in a text.<ref>R. Navigli. [http://www.dsi.uniroma1.it/~navigli/pubs/ACM_Survey_2009_Navigli.pdf Word Sense Disambiguation: A Survey], ''ACM Computing Surveys'', 41(2), 2009, pp. 1–69</ref> However, it has been argued that WordNet encodes sense distinctions that are too fine-grained. This issue prevents WSD systems from achieving a level of performance comparable to that of humans, who do not always agree when confronted with the task of selecting a sense from a dictionary that matches a word in a context. The granularity issue has been tackled by proposing [[cluster analysis|clustering]] methods that automatically group together similar senses of the same word.<ref>E. Agirre, O. Lopez. 2003.
Clustering WordNet Word Senses. In ''Proc. of the Conference on Recent Advances on Natural Language (RANLP’03)'', Borovetz, Bulgaria, pp. 121–130.</ref><ref>R. Navigli. [http://acl.ldc.upenn.edu/P/P06/P06-1014.pdf Meaningful Clustering of Senses Helps Boost Word Sense Disambiguation Performance], In ''Proc. of the 44th Annual Meeting of the Association for Computational Linguistics joint with the 21st International Conference on Computational Linguistics (COLING-ACL 2006)'', Sydney, Australia, July 17-21st, 2006, pp. 105–112.</ref><ref>R. Snow, S. Prakash, D. Jurafsky, A. Y. Ng. 2007. [http://www.aclweb.org/anthology/D/D07/D07-1107.pdf Learning to Merge Word Senses], ''In Proc. of the 2007 Joint Conference on Empirical Methods in Natural Language Processing and Computational Natural Language Learning (EMNLP-CoNLL)'', Prague, Czech Republic, pp. 1005–1014.</ref>

=== Offensive content ===
WordNet includes words that can be perceived as [[pejorative]] or offensive.<ref>{{Cite web |last=Wong |first=Julia Carrie |author-link=Julia Carrie Wong |date=2019-09-18 |title=The viral selfie app ImageNet Roulette seemed fun – until it called me a racist slur |url=http://www.theguardian.com/technology/2019/sep/17/imagenet-roulette-asian-racist-slur-selfie |access-date=2022-10-14 |website=the Guardian |language=en}}</ref> The interpretation of a word can [[Semantic change|change over time]] and [[In-group and out-group|between social groups]], so it is not always possible for WordNet to define a word as "[[pejorative]]" or "offensive" in isolation. Therefore, people using WordNet must apply their own methods to identify offensive or pejorative words.

However, this limitation is true of other lexical resources like [[dictionary|dictionaries]] and [[thesaurus]]es, which also contain [[pejorative]] and offensive words. Some dictionaries indicate words that are [[pejorative]]s, but do not include all the contexts in which words might be acceptable or offensive to different social groups. Therefore, people using dictionaries must apply their own methods to identify all offensive words.

=== Licensed vs. Open WordNets ===
Some wordnets were subsequently created for other languages. A 2012 survey lists the wordnets and their availability.<ref>Francis Bond and Kyonghee Paik 2012a. [http://web.mysites.ntu.edu.sg/fcbond/open/pubs/2012-gwc-wn-license.pdf A survey of wordnets and their licenses]. In Proceedings of the 6th Global WordNet Conference (GWC 2012). Matsue. 64–71</ref> In an effort to propagate the usage of WordNets, the Global WordNet community had been slowly re-licensing their WordNets to an open domain where researchers and developers can easily access and use WordNets as language resources to provide [[ontology|ontological]] and [[lexicon|lexical]] knowledge in [[natural language processing|natural-language processing]] (NLP) tasks.

The Open Multilingual WordNet<ref>{{cite web|url=http://compling.hss.ntu.edu.sg/omw/|title=Open Multilingual Wordnet|website=compling.hss.ntu.edu.sg|access-date=10 April 2018}}</ref> provides access to [[Open-source license|open licensed]] wordnets in a variety of languages, all linked to the Princeton Wordnet of English (PWN). The goal is to make it easy to use wordnets in multiple languages.

== Applications ==
WordNet has been used for a number of purposes in information systems, including [[word-sense disambiguation]], [[information retrieval]], [[Document classification|automatic text classification]], [[automatic summarization|automatic text summarization]], [[machine translation]] and even automatic crossword puzzle generation.

A common use of WordNet is to determine the [[semantic similarity|similarity]] between words. Various algorithms have been proposed, including measuring the distance among words and [[Synset|synsets]] in WordNet's graph structure, such as by counting the number of edges among synsets. The intuition is that the closer two words or synsets are, the closer their meaning. A number of WordNet-based word similarity algorithms are implemented in a [[Perl]] package called WordNet::Similarity,<ref>{{cite web|url=http://www.d.umn.edu/~tpederse/similarity.html |title=Ted Pedersen - WordNet::Similarity |publisher=D.umn.edu |date=2008-06-16 |access-date=2014-03-11}}</ref> and in a [[Python (programming language)|Python]] package called [[NLTK]].<ref>[https://likegeeks.com/nlp-tutorial-using-python-nltk NLP using Python NLTK]/</ref> Other more sophisticated WordNet-based similarity techniques include ADW,<ref>M. T. Pilehvar, D. Jurgens and R. Navigli.  [http://wwwusers.di.uniroma1.it/~navigli/pubs/ACL_2013_Pilehvar_Jurgens_Navigli.pdf Align, Disambiguate and Walk: A Unified Approach for Measuring Semantic Similarity.]. Proc. of the 51st Annual Meeting of the Association for Computational Linguistics (ACL 2013), Sofia, Bulgaria, August 4–9, 2013, pp. 1341-1351.</ref> whose implementation is available in [[Java (programming language)|Java]]. WordNet can also be used to inter-link other vocabularies.<ref>{{cite journal  |vauthors=Ballatore A, etal |volume=20|issue=2| arxiv=1404.5372| journal=Annals of GIS |title=Linking geographic vocabularies through WordNet |date=2014|pages=73–84|doi=10.1080/19475683.2014.904440|bibcode=2014AnGIS..20...73B|s2cid=9246582}}</ref>

== Interfaces ==
Princeton maintains a list of related projects<ref>{{cite web|url=http://wordnet.princeton.edu/related-projects/ |title=Related projects - WordNet - Related projects |publisher=Wordnet.princeton.edu |date=2014-01-06 |access-date=2018-06-22}}</ref> that includes links to some of the widely used [[application programming interface]]s available for accessing WordNet using various programming languages and environments.

== Related projects and extensions ==
WordNet is connected to several databases of the [[Semantic Web]]. WordNet is also commonly reused via mappings between the WordNet synsets and the categories from ontologies. Most often, only the top-level categories of WordNet are mapped.

=== Global WordNet Association ===
The Global WordNet Association (GWA)<ref>{{cite web|author=The Global WordNet Association |url=http://www.globalwordnet.org/ |title=globalwordnet.org |publisher=globalwordnet.org |date=2010-02-04 |access-date=2014-03-11}}</ref> is a public and non-commercial organization that provides a platform for discussing, sharing and connecting wordnets for all languages in the world. The GWA also promotes the standardization of wordnets across languages, to ensure its uniformity in enumerating the synsets in human languages. The GWA keeps a list of wordnets developed around the world.<ref>{{cite web|title=Wordnets in the World|url=http://www.globalwordnet.org/gwa/wordnet_table.html|archive-url=https://web.archive.org/web/20111021114613/http://www.globalwordnet.org/gwa/wordnet_table.html |archive-date=2011-10-21}}</ref>

=== Other languages ===<!-- Please respect alphabetical order -->
* [[Arabic WordNet]]:<ref>Black W., Elkateb S., Rodriguez H., Alkhalifa M., Vossen P., Pease A., Bertran M., Fellbaum C., (2006) The Arabic WordNet Project, Proceedings of LREC 2006</ref><ref>Lahsen Abouenour, Karim Bouzoubaa, Paolo Rosso (2013) On the evaluation and improvement of Arabic WordNet coverage and usability, Language Resources and Evaluation 47(3) pp 891–917</ref> WordNet for Arabic language.
* [[Arabic Ontology]], a linguistic ontology that has the same structure as wordnet, and mapped to it. 
* The BalkaNet project<ref>D. Tufis, D. Cristea, S. Stamou. 2004. [http://www.racai.ro/~tufis/papers/Tufis-CS-ROMJIST2004.pdf Balkanet: Aims, methods, results and perspectives. A general overview]. ''Romanian J. Sci. Tech. Inform. (Special Issue on Balkanet)'', 7(1-2), pp. 9–43.</ref> has produced WordNets for six European languages (Bulgarian, Czech, Greek, Romanian, Turkish and Serbian). For this project, a freely available XML-based WordNet editor was developed. This editor – VisDic – is not in active development anymore, but is still used for the creation of various WordNets. Its successor, DEBVisDic, is client-server application and is currently used for the editing of several WordNets (Dutch in Cornetto project, Polish, Hungarian, several African languages, Chinese).
* [[BulNet]] is a Bulgarian version of the WordNet developed at the Department of Computational Linguistics of the [[Institute for Bulgarian Language]], Bulgarian Academy of Sciences.<ref>{{cite web|url=http://dcl.bas.bg/BulNet/general_en.html |title=BulNet |publisher=dcl.bas.bg |access-date=2015-05-07}}</ref>
* CWN (Chinese Wordnet or 中文詞彙網路) supported by [[National Taiwan University]].<ref>[http://lope.linguistics.ntu.edu.tw/cwn/ Chinese Wordnet (中文詞彙網路) official page] at National Taiwan University</ref>
* The [[EuroWordNet]] project<ref>P. Vossen, Ed. 1998. EuroWordNet: A Multilingual Database with Lexical Semantic Networks. Kluwer, Dordrecht, The Netherlands.</ref> 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.<ref>{{cite web|url=http://www.globalwordnet.org/ |title=The Global WordNet Association |publisher=Globalwordnet.org |date=2010-02-04 |access-date=2014-01-05}}</ref> [[Oxford University Press]], the publisher of the [[Oxford English Dictionary]], has voiced plans to produce their own online competitor to WordNet.{{Citation needed|date=May 2009}}
* FinnWordNet is a Finnish version of the WordNet where all entries of the original English WordNet were translated.<ref>{{cite web|url=http://www.ling.helsinki.fi/en/lt/research/finnwordnet/ |title=FinnWordNet – The Finnish WordNet - Department of General Linguistics |publisher=Ling.helsinki.fi |access-date=2014-01-05}}</ref>
* [[GermaNet]] is a German version of the WordNet developed by the University of Tübingen.<ref>{{cite web|url=http://www.sfs.uni-tuebingen.de/lsd/index.shtml |title=GermaNet |publisher=Sfs.uni-tuebingen.de |access-date=2014-03-11}}</ref>
* The [[IndoWordNet]]<ref name="PushpakBhattacharyya">Pushpak Bhattacharyya, IndoWordNet, Lexical Resources Engineering Conference 2010 (LREC 2010), Malta, May, 2010.</ref> is a linked lexical knowledge base of wordnets of 18 scheduled languages of India viz., [[Assamese language|Assamese]], [[Bangla (language)|Bangla]], [[Bodo language|Bodo]], [[Gujarati language|Gujarati]], [[Hindi]], [[Kannada]], [[Kashmiri language|Kashmiri]], [[Konkani language|Konkani]], [[Malayalam]], [[Meitei language|Meitei]] (Manipuri), [[Marathi language|Marathi]], [[Nepali language|Nepali]], [[Odia language|Odia]], [[Punjabi language|Punjabi]], [[Sanskrit]], [[Tamil language|Tamil]], [[Telugu language|Telugu]] and [[Urdu]].
* JAWS (Just Another WordNet Subset), another French version of WordNet<ref>C. Mouton, G. de Chalendar. 2010.[http://www.iro.umontreal.ca/~felipe/TALN2010/Xml/Papers/all/taln2010_submission_71.pdf JAWS : Just Another WordNet Subset]. In ''Proc. of TALN 2010''.</ref> built using the Wiktionary and semantic spaces
* [https://www.aclweb.org/anthology/Y11-1027.pdf WordNet Bahasa]: WordNet for Malay and Indonesia language, developed by [[Nanyang Technological University|Nanyang University of Technology]].
* [[Malayalam WordNet]], developed by [[Cochin University of Science and Technology|Cochin University Of Science and Technology]].<ref>[http://malayalamwordnet.cusat.ac.in/ Website]</ref>
* Multilingual Central Repository (MCR) integrates in the same EuroWordNet framework wordnets from Spanish, Catalan, Basque, Galician and Portuguese liked to English.<ref>{{cite web|url=http://adimen.si.ehu.es/web/mcr/ |title=MCR 3.0 &#124; Adimen |publisher=Adimen.si.ehu.es |date= |accessdate=2022-03-21}}</ref>
* The MultiWordNet project,<ref>E. Pianta, L. Bentivogli, C. Girardi. 2002. [http://multiwordnet.itc.it/paper/MWN-India-published.pdf MultiWordNet: Developing an aligned multilingual database]. In ''Proc. of the 1st International Conference on Global WordNet'', Mysore, India, pp. 21–25.</ref> a multilingual WordNet aimed at producing an Italian WordNet strongly aligned with the Princeton WordNet.
* OpenDutchWordNet,<ref>{{cite web|url=http://wordpress.let.vupr.nl/odwn/ |title=Open Dutch WordNet |publisher=Wordpress.let.vupr.nl |date=2015-10-28 |accessdate=2022-03-21}}</ref> is a Dutch lexical semantic database.
* OpenWN-PT is a Brazilian Portuguese version of the original WordNet freely available for download under CC-BY-SA license.<ref>{{cite web|url=https://github.com/arademaker/openWordnet-PT |title=arademaker/openWordnet-PT — GitHub |publisher=Github.com |access-date=2014-01-05}}</ref>
* [[plWordNet]]<ref>[http://plwordnet.pwr.wroc.pl/wordnet/ official webpage]</ref> is a Polish-language version of WordNet developed by [[Wrocław University of Technology]].
* PolNet<ref>[http://www.ltc.amu.edu.pl/polnet/ official webpage]</ref> is a Polish-language version of WordNet developed by [[Adam Mickiewicz University in Poznań]] (distributed under CC BY-NC-ND 3.0 license).
Projects such as BalkaNet and EuroWordNet made it feasible to create standalone wordnets linked to the original one. Two such projects were the Russian WordNet, patronized by [[Petersburg State University of Means of Communication]]<ref>{{cite web|url=http://www.pgups.ru/abitur/inostrancam/inter/ruwordnet/ |title=Русский WordNet |publisher=Pgups.ru |access-date=2014-01-05}}</ref> and led by S.A. Yablonsky,<ref>{{cite journal|last1=Balkova|first1=Valentina|last2=Sukhonogov|first2=Andrey|last3=Yablonsky|first3=Sergey|title=Russian WordNet From UML-notation to Inter net/Intranet Database Implementation|journal=GWC 2004 Proceedings|date=2003|pages=31–38|url=http://hnk.ffzg.hr/bibl/gwc2004/pdf/127.pdf|access-date=12 March 2017}}</ref> and Russnet,<ref>{{cite web|url=http://project.phil.spbu.ru/RussNet/index_ru.shtml |title=RussNet: Главная страница |publisher=Project.phil.spbu.ru |access-date=2014-03-11}}</ref> by [[Saint Petersburg State University]].
* UWN is an automatically constructed multilingual lexical knowledge base extending WordNet to cover over a million words in many different languages.<ref>{{cite web|url=http://www.mpi-inf.mpg.de/yago-naga/uwn |title=UWN: Towards a Universal Multilingual Wordnet - D5: Databases and Information Systems (Max-Planck-Institut für Informatik) |publisher=Mpi-inf.mpg.de |date=2011-08-14 |access-date=2014-01-05}}</ref>
* WOLF (WordNet Libre du Français), a French version of WordNet.<ref>S. Benoît, F. Darja. 2008. [http://alpage.inria.fr/~sagot/pub/Ontolex08.pdf Building a free French wordnet from multilingual resources]. In ''Proc. of Ontolex 2008'', Marrakech, Maroc.</ref>

=== Linked data ===
* [[BabelNet]],<ref>R. Navigli, S. P. Ponzetto. [http://www.aclweb.org/anthology/P/P10/P10-1023.pdf BabelNet: Building a Very Large Multilingual Semantic Network]. Proc. of the 48th Annual Meeting of the Association for Computational Linguistics (ACL 2010), Uppsala, Sweden, July 11–16, 2010, pp. 216–225.</ref> a very large multilingual [[semantic network]] with millions of concepts obtained by integrating WordNet and Wikipedia using an automatic mapping algorithm.
* The [[Suggested Upper Merged Ontology|SUMO]] ontology<ref>I. Niles, A. Pease 2001. [https://www.researchgate.net/publication/221234966_Towards_a_Standard_Upper_Ontology Toward a Standard Upper Ontology: A large ontology for the Semantic Web and its applications]. In ''Proceedings of the 2nd International Conference on Formal Ontology in Information Systems (FOIS-2001)'',</ref> has a complete manual mapping [https://github.com/ontologyportal/sumo/tree/master/WordNetMappings] <ref>I. Niles, A. Pease 2003. [https://www.researchgate.net/publication/2880063_Linking_Lexicons_and_Ontologies_Mapping_WordNet_to_the_Suggested_Upper_Merged_Ontology Linking Lexicons and Ontologies: Mapping WordNet to the Suggested Upper Merged Ontology], In ''Proceedings of the IEEE International Conference on Information and Knowledge Engineering'', pp 412-416</ref> between all of the WordNet synsets and all of SUMO (including its domain ontologies, when WordNet contains a word sense for a given SUMO term) which is browsable at, for example [https://sigma.ontologyportal.org:8443/sigma/Browse.jsp?kb=SUMO&lang=EnglishLanguage&flang=SUO-KIF&term=Object].
* [[OpenCyc]],<ref>S. Reed and D. Lenat. 2002. [http://www.cyc.com/doc/white_papers/mapping-ontologies-into-cyc_v31.pdf Mapping Ontologies into Cyc]. In ''Proc. of AAAI 2002 Conference Workshop on Ontologies For The Semantic Web'', Edmonton, Canada, 2002</ref> an open [[ontology (information science)|ontology]] and [[knowledge base]] of everyday common sense knowledge, has 12,000 terms linked to WordNet synonym sets.
* [[Descriptive Ontology for Linguistic and Cognitive Engineering|DOLCE]],<ref>Masolo, C., Borgo, S., Gangemi, A., Guarino, N., Oltramari, A., Schneider, L.S. 2002. [http://www.loa-cnr.it/Papers/WonderWebD17V2.0.pdf WonderWeb Deliverable D17. The WonderWeb Library of Foundational Ontologies and the DOLCE ontology]. Report (ver. 2.0, 15-08-2002)</ref> is the first module of the WonderWeb Foundational Ontologies Library (WFOL). This upper-ontology has been developed in light of rigorous ontological principles inspired by the philosophical tradition, with a clear orientation toward language and cognition. OntoWordNet<ref>Gangemi, A., Guarino, N., Masolo, C., Oltramari, A. 2003 [http://www.loa-cnr.it/Papers/AIMag24-03-003.pdf Sweetening WordNet with DOLCE]. In AI Magazine 24(3): Fall 2003, pp. 13–24</ref> is the result of an experimental alignment of WordNet's upper level with DOLCE. It is suggested that such alignment could lead to an "ontologically sweetened" WordNet, meant to be conceptually more rigorous, cognitively transparent, and efficiently exploitable in several applications.
* [[DBpedia]],<ref>C. Bizer, J. Lehmann, G. Kobilarov, S. Auer, C. Becker, R. Cyganiak, S. Hellmann, [http://www.wiwiss.fu-berlin.de/en/institute/pwo/bizer/research/publications/Bizer-etal-DBpedia-CrystallizationPoint-JWS-Preprint.pdf DBpedia – A crystallization point for the Web of Data]. Web Semantics, 7(3), 2009, pp. 154–165</ref> a database of structured information, is linked to WordNet.
* The [[eXtended WordNet]]<ref>S. M. Harabagiu, G. A. Miller, D. I. Moldovan. 1999. [http://www.ldc.upenn.edu/acl/W/W99/W99-0501.pdf WordNet 2 – A Morphologically and Semantically Enhanced Resource]. In ''Proc. of the ACL SIGLEX Workshop: Standardizing Lexical Resources'', pp. 1–8.</ref> 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 freely available under a license similar to WordNet's.
* The [[GCIDE]] project produced a dictionary by combining a [[public domain]] ''[[Webster's Dictionary]]'' from 1913 with some WordNet definitions and material provided by volunteers. It was released under the [[copyleft]] license [[GNU General Public License|GPL]].
* [[ImageNet]] is an image database organized according to the WordNet hierarchy (currently only the nouns), in which each node of the hierarchy is depicted by millions of images.<ref>J. Deng, W. Dong, R. Socher, L. Li, K. Li, L. Fei-Fei. [https://nlpainter.googlecode.com/svn-history/r16/trunk/papers/ImageNet__cvpr09.pdf ImageNet: A Large-Scale Hierarchical Image Database]. In ''Proc. of 2009 IEEE Conference on Computer Vision and Pattern Recognition''</ref> Currently, it has over 500 images per node on average.
* BioWordnet, a biomedical extension of wordnet was abandoned due to issues about stability over versions.<ref>M. Poprat, E. Beisswanger, U. Hahn. 2008. [http://www.aclweb.org/anthology/W/W08/W08-0507.pdf Building a BIOWORDNET by Using WORDNET’s Data Formats and WORDNET’s Software Infrastructure – A Failure Story]. In ''Proc. of the Software Engineering, Testing, and Quality Assurance for Natural Language Processing Workshop'', pp. 31–39.</ref>
* WikiTax2WordNet, a mapping between WordNet synsets and [[Wikipedia:Categorization|Wikipedia categories]].<ref>S. Ponzetto, R. Navigli. [http://ijcai.org/papers09/Papers/IJCAI09-343.pdf Large-Scale Taxonomy Mapping for Restructuring and Integrating Wikipedia], In ''Proc. of the 21st International Joint Conference on Artificial Intelligence (IJCAI 2009)'', Pasadena, California, July 14-17th, 2009, pp. 2083–2088.</ref>
* WordNet++, a resource including over millions of semantic edges harvested from Wikipedia and connecting pairs of WordNet synsets.<ref>S. P. Ponzetto, R. Navigli. [https://aclanthology.org/P10-1154.pdf Knowledge-rich Word Sense Disambiguation rivaling supervised systems]. In Proc. of the 48th Annual Meeting of the Association for Computational Linguistics (ACL), 2010, pp. 1522–1531.</ref>
* SentiWordNet, a resource for supporting opinion mining applications obtained by tagging all the WordNet 3.0 synsets according to their estimated degrees of positivity, negativity, and neutrality.<ref>S. Baccianella, A. Esuli and F. Sebastiani. [http://nemis.isti.cnr.it/sebastiani/Publications/LREC10.pdf SentiWordNet 3.0: An Enhanced Lexical Resource for Sentiment Analysis and Opinion Mining]. In Proceedings of the 7th Conference on Language Resources and Evaluation (LREC'10), Valletta, MT, 2010, pp. 2200–2204.</ref>
* ColorDict, is an Android application to mobiles phones that use Wordnet database and others, like Wikipedia.
* [[UBY-LMF]] a database of 10 resources including WordNet.

=== Related projects ===
*[[TaxoLLaMa]] is a WordNet-based model designed to enhance LLMs' ability to capture lexical-semantic knowledge.
* [[FrameNet]] is a lexical database that shares some similarities with, and refers to, WordNet. 
* [[Lexical markup framework]] (LMF) is an ISO standard specified within [[ISO/TC37]] in order to define a common standardized framework for the construction of lexicons, including WordNet. The subset of LMF for Wordnet is called Wordnet-LMF. An instantiation has been made within the KYOTO project.<ref>Piek Vossen, Claudia Soria, Monica Monachini: Wordnet-LMF: a standard representation for multilingual wordnets, in ''LMF Lexical Markup Framework'', edited by Gil Francopoulo ISTE / Wiley 2013 ({{ISBN|978-1-84821-430-9}})</ref>
* [[Universal Networking Language|UNL Programme]] is a project under the auspices of [[United Nations|UNO]] aimed to consolidate lexicosemantic data of many languages to be used in machine translation and [[information extraction]] systems.
* [https://meaningmonkey.org/ Meaning Monkey] is a free online dictionary based on the WordNet database.
* [https://dictionary.video/ Dictionary.video] is a video dictionary focusing on pronunciations. Its text part is extended from WordNet.

== Distributions ==
WordNet Database is distributed as a dictionary package (usually a single file) for the following software:
* [[Babylon (software)|Babylon]]<ref>{{cite web|url=http://www.babylon.com/free-dictionaries/reference/encyclopedias/WordNet-2.0/42406.html |title=Babylon WordNet |publisher=Babylon.com |access-date=2014-03-11}}</ref>
* GoldenDict<ref>{{cite web|url=http://sourceforge.net/projects/goldendict/files/dictionaries |title=GoldenDict - Browse /dictionaries at Sourceforge.net |publisher=Sourceforge.net |date=2010-12-01 |access-date=2014-01-05}}</ref>
* [[Lingoes (program)|Lingoes]]<ref>{{cite web|url=http://www.lingoes.net/en/dictionary/dict_down.php?id=12D98EC3940843498672A92149455292 |title=Lingoes WordNet |publisher=Lingoes.net |date=2007-11-16 |access-date=2014-03-11}}</ref>
* [https://lexsemantic.com LexSemantic] : Digital Platform for publishing reference works (dictionaries, encyclopedias, etc.). Includes WordnetPlus.

== See also ==
* [[Lexical Markup Framework]]
* [[Machine-readable dictionary]]
* [[Synonym Ring]]
* [[Taxonomy (general)|Taxonomy]]

== References ==
{{reflist|colwidth=30em}}

== External links ==
* {{Official website|http://wordnet.princeton.edu/}}
* {{cite web |url= http://malayalamwordnet.cusat.ac.in/ |title= Malayalam WordNet |work= Computer Science |publisher= Cochin University of Science & Technology}}
* {{cite web |url= http://ainthesaurus.it <!-- 01/2020 aka http://www.iinformatica.it/ainthesaurus --> |title= Adjectives, Intensifiers, Negations (AIN) Thesaurus |work= Italian Sentiment |first= Maria |last= Pilato |url-access= subscription  }}

{{Lexicography}}
{{Natural Language Processing}}

{{Authority control}}

{{DEFAULTSORT:Wordnet}}
[[Category:Online English dictionaries]]
[[Category:Lexical databases]]
[[Category:Knowledge representation]]
[[Category:Computational linguistics]]
[[Category:Open data]]
[[Category:Projects established in 1985]]
[[Category:1985 establishments in New Jersey]]
[[Category:Corpus linguistics]]
[[Category:Free software programmed in Prolog]]
[[Category:Software using the BSD license]]