Text corpus

Last updated September 22, 2024

In linguistics and natural language processing, a corpus (pl.: corpora) or text corpus is a dataset, consisting of natively digital and older, digitalized, language resources, either annotated or unannotated.

Overview

A corpus may contain texts in a single language (monolingual corpus) or text data in multiple languages (multilingual corpus).

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 (base) form of each word. When the language of the corpus is not a working language of the researchers who use it, interlinear glossing is used to make the annotation bilingual.

Some corpora have further structured levels of analysis applied. In particular, smaller corpora may be fully parsed. Such corpora are usually called Treebanks or Parsed Corpora. The difficulty of ensuring that the entire corpus is completely and consistently annotated means that these corpora are usually smaller, containing around one to three million words. Other levels of linguistic structured analysis are possible, including annotations for morphology, semantics and pragmatics.

Applications

Corpora are the main knowledge base in corpus linguistics. Other notable areas of application include:

Language technology, natural language processing, computational 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 models for part of speech tagging and other purposes. Corpora and frequency lists derived from them are useful for language teaching. Corpora can be considered as a type of foreign language writing aid as the contextualised grammatical knowledge acquired by non-native language users through exposure to authentic texts in corpora allows learners to grasp the manner of sentence formation in the target language, enabling effective writing.^[1]

Machine translation
- Multilingual corpora that have been specially formatted for side-by-side comparison are called aligned parallel corpora. There are two main types of parallel corpora which contain texts in two languages. In a translation corpus, the texts in one language are translations of texts in the other language. In a comparable corpus, the texts are of the same kind and cover the same content, but they are not translations of each other.^[2] To exploit a parallel text, some kind of text alignment identifying equivalent text segments (phrases or sentences) is a prerequisite for analysis. Machine translation algorithms for translating between two languages are often trained using parallel fragments comprising a first-language corpus and a second-language corpus, which is an element-for-element translation of the first-language corpus.^[3]

Philologies
- Text corpora are also used in the study of historical documents, for example in attempts to 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

Related Research Articles

Computational linguistics is an interdisciplinary field concerned with the computational modelling of natural language, as well as the study of appropriate computational approaches to linguistic questions. In general, computational linguistics draws upon linguistics, computer science, artificial intelligence, mathematics, logic, philosophy, cognitive science, cognitive psychology, psycholinguistics, anthropology and neuroscience, among others.

Natural language processing (NLP) is an interdisciplinary subfield of computer science and artificial intelligence. It is primarily concerned with providing computers with the ability to process data encoded in natural language and is thus closely related to information retrieval, knowledge representation and computational linguistics, a subfield of linguistics. Typically data is collected in text corpora, using either rule-based, statistical or neural-based approaches in machine learning and deep learning.

Corpus linguistics is an empirical method for the study of language by way of a text corpus. Corpora are balanced, often stratified collections of authentic, "real world", text of speech or writing that aim to represent a given linguistic variety. Today, corpora are generally machine-readable data collections.

Word-sense disambiguation is the process of identifying which sense of a word is meant in a sentence or other segment of context. In human language processing and cognition, it is usually subconscious.

A parallel text is a text placed alongside its translation or translations. Parallel text alignment is the identification of the corresponding sentences in both halves of the parallel text. The Loeb Classical Library and the Clay Sanskrit Library are two examples of dual-language series of texts. Reference Bibles may contain the original languages and a translation, or several translations by themselves, for ease of comparison and study; Origen's Hexapla placed six versions of the Old Testament side by side. A famous example is the Rosetta Stone, whose discovery allowed the Ancient Egyptian language to begin being deciphered.

In corpus linguistics, part-of-speech tagging, also called grammatical tagging is the process of marking up a word in a text (corpus) as corresponding to a particular part of speech, based on both its definition and its context. A simplified form of this is commonly taught to school-age children, in the identification of words as nouns, verbs, adjectives, adverbs, etc.

The American National Corpus (ANC) is a text corpus of American English containing 22 million words of written and spoken data produced since 1990. Currently, the ANC includes a range of genres, including emerging genres such as email, tweets, and web data that are not included in earlier corpora such as the British National Corpus. It is annotated for part of speech and lemma, shallow parse, and named entities.

In linguistics, a treebank is a parsed text corpus that annotates syntactic or semantic sentence structure. The construction of parsed corpora in the early 1990s revolutionized computational linguistics, which benefitted from large-scale empirical data.

Linguistic categories include

The International Corpus of English (ICE) is a set of text corpora representing varieties of English from around the world. Over twenty countries or groups of countries where English is the first language or an official second language are included.

Eckhard Bick is a German-born Esperantist who studied medicine in Bonn but now works as a researcher in computational linguistics. He was active in an Esperanto youth group in Bonn and in the Germana Esperanto-Junularo, a nationwide Esperanto youth federation. Since his marriage to a Danish woman he and his family live in Denmark.

<span class="mw-page-title-main">Quranic Arabic Corpus</span>

The Quranic Arabic Corpus is an annotated linguistic resource consisting of 77,430 words of Quranic Arabic. The project aims to provide morphological and syntactic annotations for researchers wanting to study the language of the Quran.

SemEval is an ongoing series of evaluations of computational semantic analysis systems; it evolved from the Senseval word sense evaluation series. The evaluations are intended to explore the nature of meaning in language. While meaning is intuitive to humans, transferring those intuitions to computational analysis has proved elusive.

Deep Linguistic Processing with HPSG - INitiative (DELPH-IN) is a collaboration where computational linguists worldwide develop natural language processing tools for deep linguistic processing of human language. The goal of DELPH-IN is to combine linguistic and statistical processing methods in order to computationally understand the meaning of texts and utterances.

The following outline is provided as an overview of and topical guide to natural-language processing:

Sketch Engine is a corpus manager and text analysis software developed by Lexical Computing since 2003. Its purpose is to enable people studying language behaviour to search large text collections according to complex and linguistically motivated queries. Sketch Engine gained its name after one of the key features, word sketches: one-page, automatic, corpus-derived summaries of a word's grammatical and collocational behaviour. Currently, it supports and provides corpora in over 90 languages.

Manually Annotated Sub-Corpus (MASC) is a balanced subset of 500K words of written texts and transcribed speech drawn primarily from the Open American National Corpus (OANC). The OANC is a 15 million word corpus of American English produced since 1990, all of which is in the public domain or otherwise free of usage and redistribution restrictions.

Universal Dependencies, frequently abbreviated as UD, is an international cooperative project to create treebanks of the world's languages. These treebanks are openly accessible and available. Core applications are automated text processing in the field of natural language processing (NLP) and research into natural language syntax and grammar, especially within linguistic typology. The project's primary aim is to achieve cross-linguistic consistency of annotation, while still permitting language-specific extensions when necessary. The annotation scheme has it roots in three related projects: Stanford Dependencies, Google universal part-of-speech tags, and the Interset interlingua for morphosyntactic tagsets. The UD annotation scheme uses a representation in the form of dependency trees as opposed to a phrase structure trees. At the present time, there are just over 200 treebanks of more than 100 languages available in the UD inventory.

In linguistics and language technology, a language resource is a "[composition] of linguistic material used in the construction, improvement and/or evaluation of language processing applications, (...) in language and language-mediated research studies and applications."

References

↑ Yoon, H., & Hirvela, A. (2004). ESL Student Attitudes toward Corpus Use in L2 Writing. Journal of Second Language Writing, 13(4), 257–283. Retrieved 21 March 2012.
↑ Wołk, K.; Marasek, K. (7 April 2014). "Real-Time Statistical Speech Translation". New Perspectives in Information Systems and Technologies, Volume 1. Advances in Intelligent Systems and Computing. Vol. 275. Springer. pp. 107–114. arXiv: 1509.09090 . doi:10.1007/978-3-319-05951-8_11. ISBN 978-3-319-05950-1. ISSN 2194-5357. S2CID 15361632.
↑ Wolk, Krzysztof; Marasek, Krzysztof (2015). "Tuned and GPU-accelerated parallel data mining from comparable corpora". In Král, Pavel; Matousek, Václav (eds.). Text, Speech, and Dialogue – 18th International Conference, TSD 2015, Pilsen, Czech Republic, September 14–17, 2015, Proceedings. Lecture Notes in Computer Science. Vol. 9302. Springer. pp. 32–40. arXiv: 1509.08639 . doi:10.1007/978-3-319-24033-6_4. ISBN 978-3-319-24032-9.

External links

ACL SIGLEX Resource Links: Text Corpora Archived 2013-08-13 at the Wayback Machine
Developing Linguistic Corpora: a Guide to Good Practice
Free samples (not free), web-based corpora (45-425 million words each): American (COCA, COHA, TIME), British (BNC), Spanish, Portuguese
Intercorp Building synchronous parallel corpora of the languages taught at the Faculty of Arts of Charles University.
Sketch Engine: Open corpora with free access
TS Corpus – A Turkish Corpus freely available for academic research.
Turkish National Corpus – A general-purpose corpus for contemporary Turkish
Corpus of Political Speeches, Free access to political speeches by American and Chinese politicians, developed by Hong Kong Baptist University Library
Russian National Corpus

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[Yoon-1] Yoon, H., & Hirvela, A. (2004). ESL Student Attitudes toward Corpus Use in L2 Writing. Journal of Second Language Writing, 13(4), 257–283. Retrieved 21 March 2012.

[2] Wołk, K.; Marasek, K. (7 April 2014). "Real-Time Statistical Speech Translation". New Perspectives in Information Systems and Technologies, Volume 1. Advances in Intelligent Systems and Computing. Vol. 275. Springer. pp. 107–114. arXiv: 1509.09090 . doi:10.1007/978-3-319-05951-8_11. ISBN 978-3-319-05950-1. ISSN 2194-5357. S2CID 15361632.

[3] Wolk, Krzysztof; Marasek, Krzysztof (2015). "Tuned and GPU-accelerated parallel data mining from comparable corpora". In Král, Pavel; Matousek, Václav (eds.). Text, Speech, and Dialogue – 18th International Conference, TSD 2015, Pilsen, Czech Republic, September 14–17, 2015, Proceedings. Lecture Notes in Computer Science. Vol. 9302. Springer. pp. 32–40. arXiv: 1509.08639 . doi:10.1007/978-3-319-24033-6_4. ISBN 978-3-319-24032-9.

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