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Computational Linguistics

 INTRODUCTION

 DEFINITION

 HISTORY OF COMPUTER

 ORIGINS OF COMPUTATIONAL LINGUISTICS

 APPLICATION AREAS

 APPROACHES

 CONCLUSION

 REFERENCES

Introduction

Traditionally, computational linguistics was usually performed by computer scientists

specialized in the application of computers to the processing of a natural language.

Computational linguists often work as members of interdisciplinary teams, including linguists

(specifically trained in linguistics), language experts (persons with some level of ability in the

languages relevant to a given project), and computer scientists. In general, computational

linguistics involves linguists, computer scientists, experts in artificial intelligence,

mathematicians, logicians, philosophers, cognitive scientists, cognitive psychologists,

psycholinguists, anthropologists and neuroscientists, among others.

Definitions

Different people have defined computational linguistics almost in the same way. Here are some

definitions;

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 Computational linguistics is an interdisciplinary field dealing with the statistical or rule-

based modeling of natural language from a computational perspective.

 The Association for Computational Linguistics defines computational linguistics as:

“...the scientific study of language from a computational perspective. Computational

linguists are interested in providing computational models of various kinds of linguistic

phenomena.”

 Igor Bolshakov and Alexander Gelbukh define Computational Linguistics in the book

“Computational Linguistics” in these words, “Computational Linguistics might be

considered as a synonym of automatic processing of natural language, since the main task

of computational linguistics is just the construction of computer programs to process

words and texts in natural language.”

 Computational Linguistics is the scientific study of language from a computational

perspective. Computational linguists are interested in providing computational models of

various kinds of linguistic phenomena. These models may be :knowledge based” (“hand-

crafted”) or data-driven” (“statistical” or “empirical”)

 Ralph Grisman in his book “Computational Linguistics: An Introduction,” published by

Cambridge University Press 1986 has this to say; “Computational linguistics is the study

of computer systems for understanding and generating natural language.”

History of the Digital Computer

It is not a surprise that the history of Computational Linguistics is closely connected to the

development of the digital computer. The theoretical foundations of Computational linguistics

are in the field of mathematical linguistics, formal language theory and in the field of

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information theory. The first application of Computational Linguistics was in the area of

machine translation. Therefore, the first professional organization was called Association for

Machine Translation and Computational Linguistics.

In 1939, John J. Atanasoff designs a prototype for the ABC (Atanasoff-Berry Computer) with the

help of graduate student Clifford Berry at Iowa State College. In 1973 a judge ruled it the first

automatic digital computer.

In 1941, Colossus computer designed by M.H.A. Neuman at the university of Manchester

England, building on ideas of Alan M. Turing used by British code breakers during the World

War II.

In electronics, a vacuum tube is a device used to amplify, switch, otherwise modify or create an

electrical signal. These enabled the development of electronics technology (radio, TV, radar,

Hifi, telephone networks, digital computers and industrial process control.

For most purposes, the vacuum tube has been replaced by solid-state semiconductor devices such

as transistors and diodes. These are smaller, more efficient, more reliable and cheaper – either as

discrete devices or integrated circuits. However tubes are still used in monitors (cathode ray

tube) and microwave ovens (magnetron)

In 1951, Remington Rand builds the first commercial Universal Automatic Computer

(UNIVAC) bettering the performance.

The First Natural Language Processing Application

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After this, computer was started being used in bi-lingual Dictionaries in the processing of

Natural Language. In 1947, Donald Booth and D.H.V. Britten worked out a detailed code for

realizing dictionary translation on a digital computer. Next year, R.H. Richens worked out a

stem-affix encoding with a longest-match strategy for stem identification and translation.

Origin of Computational Linguistics

Computational linguistics originated with efforts in the United States in the 1950s to use

computers to automatically translate texts from foreign languages, particularly Russian scientific

journals, into English. Since computers can make arithmetic calculations much faster and more

accurately than humans, it was thought they would process language with the same remarkable

capacity.

When machine translation/mechanical translation failed in accurate translations, automated

processing of human languages was recognized as far more complex than had originally been

assumed. Computational linguistics was born as the name of the new field of study devoted to

developing algorithms and software for intelligently processing language data. When artificial

intelligence came into existence in the 1960s, the field of computational linguistics became that

sub-division of artificial intelligence dealing with human-level comprehension and production of

natural languages.

For translation from one language into another, it was observed that one had to understand the

grammar of both languages, including both morphology and syntax. In order to understand

syntax, one had to also understand the semantics and the lexicon and even to understand

something of the pragmatics of language use. Thus, what started as an effort to translate between

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languages evolved into an entire discipline devoted to understanding how to represent and

process natural languages using computers.

L(A) Grammar+morphology+syntax+semantics+lexicon+pragmtics L(B)

Nowadays research within the scope of computational linguistics is done at computational

linguistics departments, computational linguistics laboratories, computer science departments,

and linguistics departments.

Application Areas

Computational Linguistics can be used in language processing for machine translation, speech

recognition, speech synthesis and man-machine interfaces. It can also be put to use in language

learning, language description (computer aided dialectology) . moreover, it can be applied in

intelligent word processing (spelling correction, grammar correction) document management

(find relevant docuents in collections, establish authorship of documents, catch plagiarism,

extract information from documents, classify documents, summarize documents and summarize

document collections).

Approaches

Just as computational linguistics can be performed by experts in a variety of fields, and through a

plethora of departments, so too can the research fields open a diverse range of topics. There are

four main areas of discourse:

1) developmental linguistics,

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2) structural linguistics,

3) linguistic production, and

4) linguistic comprehension.

Subfields

Computational linguistics can be divided into major areas depending upon the medium of the

language being processed, whether spoken or textual; and upon the task being performed,

whether analyzing language (recognition) or synthesizing language (generation).

Speech recognition and speech synthesis deal with how spoken language can be understood

or created using computers. Parsing and generation are sub-divisions of computational

linguistics dealing respectively with taking language apart and putting it together. Machine

translation remains the sub-division of computational linguistics dealing with having

computers translate between languages.

Some of the areas of research that are studied by computational linguistics include:

 Computational complexity of natural language, largely modeled on automata theory, with

the application of context-sensitive grammar and linearly bounded Turing machines.

 Computational semantics comprises defining suitable logics for linguistic meaning

representation, automatically constructing them and reasoning with them

 Computer-aided corpus linguistics

 Design of parsers or chunkers for natural languages

 Design of taggers like POS-taggers (part-of-speech taggers)

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 Machine translation as one of the earliest and most difficult applications of computational

linguistics draws on many subfields.

 Simulation and study of language evolution in historical linguistics/glottochronology.

Conclusion

So we may say that with the passage of time use of computer is penetrating into other disciplines

and field of life, computer and linguistics will still have to go long way. The work and research

to generate and comprehend natural human language is on and it is hope that mankind will

succeed in communicating to machines effectively as and when they need and vice versa.

References

1. Wikipedia

2. Igor Bolshakov and Alexander Gelbukh “Computational Linguistics”

3. Website of The association of Computational Linguistics

4. Ralph Grisman “Computational Linguistics: An Introduction,” Cambridge University

Press 1986

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