Text corpus
In [[linguistics]], a '''corpus''' (plural ''corpora'') or '''text corpus''' is a large and structured set of texts (now usually electronically stored and processed). They are used to do statistical analysis, checking occurrences or validating linguistic rules on a specific universe.

A corpus may contain texts in a single language (''monolingual corpus'') or text data in multiple languages (''multilingual corpus'').  Multilingual corpora that have been specially formatted for side-by-side comparison are called ''aligned parallel corpora''.

In order to make the corpora more useful for doing linguistic research, they are often subjected to a process known as [[annotation]]. An example of annotating a corpus is [[part-of-speech tagging]], or ''POS-tagging'', in which information about each word's part of speech (verb, noun, adjective, etc.) is added to the corpus in the form of ''tags''. Another example is indicating the [[lemma (linguistics)|lemma]] (base) form of each word. When the language of the corpus is not a working language of the researchers who use it, interlinear [[gloss]]ing is used to make the annotation bilingual.  

Corpora are the main knowledge base in [[corpus linguistics]]. The analysis and processing of various types of corpora are also the subject of much work in [[computational linguistics]], [[speech recognition]] and [[machine translation]], where they are often used to create [[hidden Markov model]]s for POS-tagging and other purposes. Corpora and [[frequency list]]s derived from them are useful for [[language teaching]].

==Archaeological corpora==

Text corpora. are also used in the study of [[historical document]]s, for example in attempts to [[decipherment|decipher]] ancient scripts, or in [[Biblical scholarship]]. Some archaeological corpora can be of such short duration that they provide a snapshot in time. One of the shortest corpora in time, may be the 15-30 year [[Amarna letters]] texts-([[1350 BC]]). The ''corpus'' of an ancient city, (for example the "[[Kültepe]] Texts" of Turkey), may go through a series of corpora, determined by their find site dates.

== Some notable text corpora ==
English language:
* [[American National Corpus]]
* [[Bank of English]]
* [[British National Corpus]]
* [[Corpus Juris Secundum]]
* [[Corpus of Contemporary American English (COCA)]] 360 million words, 1990-2007. Freely available online.
* [[Brown Corpus]], forming part of the "Brown Family" of corpora, together with LOB, Frown and F-LOB.
* [[Oxford English Corpus]]
* [[Scottish Corpus of Texts & Speech]]
Other languages:
* [[Amarna letters]], (for [[Akkadian language|Akkadian]], Egyptian, [[Sumerogram]]'s, etc.)
* [[Bijankhan Corpus]] A Contemporary Persian Corpus for NLP researches
* [[Croatian National Corpus]]
* [[Hamshahri Corpus]] A Contemporary Persian Corpus for IR researches
* [[Neo-Assyrian Text Corpus Project]]
* [[Persian Today Corpus]]
* [[Thesaurus Linguae Graecae]] (Ancient Greek)

==See also==
* [[Concordance (publishing)|Concordance]]
* [[Corpus linguistics]]
* [[Linguistic Data Consortium]]
* [[Natural language processing]]
* [[Natural Language Toolkit]]
* [[Parallel text alignment]]
* [[Search engines]]: they access the "web corpus".
* [[Translation memory]]
* [[Treebank]]

== External links ==
* [http://corpus.byu.edu/ Freely-available, web-based corpora (100 million - 360 million words each): American, British (BNC), TIME, Spanish, Portuguese]
* {{dmoz|/Science/Social_Sciences/Linguistics/Computational_Linguistics/|Computational Linguistics}}
* [http://www.clres.com/corp.html ACL SIGLEX Resource Links: Text Corpora]
* [http://www.eva.mpg.de/lingua/files/morpheme.html The Leipzig Glossing Rules]: Conventions for interlinear [[morpheme]]-by-morpheme [[gloss]]es 
* [http://www.ahds.ac.uk/linguistic-corpora Developing Linguistic Corpora: a Guide to Good Practice]
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[[Category:Discourse analysis]]
[[Category:Corpus linguistics]]
[[Category:Computational linguistics]]
[[Category:Data mining]]

[[cs:Jazykový korpus]]
[[de:Textkorpus]]
[[el:Σώμα κειμένων]]
[[es:Corpus lingüístico]]
[[eo:Korpuso]]
[[eu:Testu corpus]]
[[fr:Corpus]]
[[gl:Corpus lingüístico]]
[[ms:Korpus]]
[[nl:Corpus (taalkunde)]]
[[ja:コーパス]]
[[pl:Korpus (językoznawstwo)]]
[[pt:Corpus lingüístico]]
[[sk:Korpus (jazykoveda)]]
[[sl:Besedilni korpus]]
[[th:คลังข้อความ]]
[[zh-yue:語料庫]]
[[zh:语料库]]