Processing: current projects and research at the IXA Group

(1)

N

atural

L

anguage

P

rocessing

:

current projects and research

at the

IXA

Group

IXA Research

Group on NLP

University of the Basque Country

(2)

Motivation

l

A language that seeks to survive in the

modern information society requires language

technology products.

l

Most of the working applications are only

available for the "big" languages.

l

"Minority" languages have to make a great

(3)

How to face the challenge?

l

Open proposal for the development of language

technology.

l

Steps to take: from necessary infrastructure to useful

LE applications.

l

Based on the twelve year-long experience of the IXA

Research Group in the field of natural language

processing applied to Basque.

(4)

IXA Research Group

on NLP (UPV/EHU) (I)

l

Main research fields:

NLP, computational

linguistics, language engineering.

l

Goal:

to collaborate on

–

laying foundations for research;

–

the development of language processing software.

(5)

FOR MORE INFO ...

http://ixa.si.ehu.es

IXA Research Group

on NLP (UPV/EHU) (II)

l

1986/1987: 4-5 university lecturers (CS)

1986/1987:

l

2000/2001:

~30

members

–

13 lecturers (11 doctorates, senior researchers)

–

13 PhD students (research grants)

–

A few research assistants assigned to projects

l

Interdisciplinary team:

computer scientists & linguists

(6)

IXA Research Group

on NLP (UPV/EHU) (III)

l

Relationships with other universities in

Euskal Herria; Madrid; Toulouse; Barcelona; Maryland,

Las Cruces (USA); Sydney (Australia); Massey (New

Zealand); Rome (Italy); Helsinki (Finland); ...

l

And companies: Hizkia, Jalgi, Egunkaria, Microsoft,

Xerox, LingSoft, LexiQuest, ...

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Funding: local government, University of the Basque

(7)

A growing number of people use

computer systems in their everyday life.

Many of these systems involve the use and

processing of language.

Document writing and correction

What is

the

language industry?

Remote information retrieval

Consultation of dictionaries and

encyclopedias

Translation of documents

Electronic messaging

(8)

Some terminology on

Natural Language Processing (I)

l

NLP

_{deals with the automatic processing of both}

spoken and written text: communicate

with/through computers by means of every day

language.

l

Computational linguistics

or computer-oriented

linguistics: formalisation of linguistic knowledge

for computer processing.

(9)

Some terminology on

Natural Language Processing (II)

l

Language engineering

: production of computer

systems which can recognise, understand,

interpret and generate human language in all its

forms.

Typical products of LE are language software systems (lingware)

such as lemmatisers, phrase recognisers, word sense

disambiguation programs, translation aids, etc.

l

All this is usually gathered under the heading of

(10)

Underlying philosophy

(I)

l

Use, share, and reuse:

–

theories, formalisms, and methodologies

–

techniques and expertise

–

technology

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Build our own linguistic resources in order to

develop:

–

general and specific tools

(11)

Underlying philosophy

(II)

As an example:

l

Several OCR programs claim to have Basque among the

languages they are set up for.

l

No one includes specific language information (dictionary,

bi-grams or tri-grams info., etc.).

l

In some of them, the use of (r acute) and similar

obsolete features is the only reason for that claim!!!.

Result

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These programs don't work with Basque texts as properly

as they do with other languages.

(12)

Strategic priorities: from basic

research to application

development

Research & development

End-user applications

Language tools

Basic & applied research

(13)

Linguistic foundations &

resources, tools and applications

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Linguistic foundations and resources:

necessary infrastructure for the automatic

processing of a language.

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Tools:

mainly intended for application

developers.

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Applications:

commercial or non-commercial,

(14)

Phase I: laying foundations

Basic Lexical Database

(15)

Phase II: first basic tools and

applications

Lemmatiser/Tagger

Morphological analyser

Statistical tools for the treatment of corpora

Comp. description

of morphology

MRD's

Morphologically annotated corpus

Enriched Lexical Database

(16)

Phase III: more advanced tools

and applications

Morphological analyser

Lemmatiser/Tagger

Statistical tools for the treatment of corpora

Lexical Database

Environment for linguistic tools integration

Basic CALL

MRD's

Comp. description

_{of morphology}

Xuxen: spelling checker/corrector

Comp.

grammar

Lexical-Surface

syntax

analyser

WSD

Web crawler

Grammar

_checker

Electronic

dictionaries

(17)

Phase IV:

multilinguality

and

general use applications

MRD's

Lexical Database

Comp. description

of morphology

Morphological analyser

Lemmatiser/Tagger

Statistical tools for the treatment of corpora

Comp.

grammar

Environment for linguistic tools integration

Electronic

dictionaries

Web crawler

Grammar

checker

Information retrieval and extraction

NL generation, translation aids, dialog systems, ...

Syntax

analyser

WSD

Xuxen: spelling checker/corrector

Advanced CALL

Morphol., synt., and semantically annotated multilingual corpus

Multilingual

lexical-semantic KB

(18)

What not to

do (I)

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Do not start developing applications before

linguistic foundations are created.

Ø

Follow, in general, the sequence stated above:

foundations, tools, and applications

.

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When a new system must be built, do not

create ad hoc linguistic resources.

Ø

Design these resources to be easily extended for

full coverage and make them reusable by any

(19)

What not to do (II): example

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Basque is a language with a very rich

morphology.

Ø

We decided not to begin with advanced

applications (machine translation, ...)

but rather to develop a broad foundation based on

lexicon and morphology.

l

Now those foundations have become the base

(20)

Reusability is a must:

example (I)

Structured electronic

dictionaries

Lemmatiser

Surface syntax

_parser

Machine-Lexical

(21)

Reusability is a must:

example (II)

Translation

aids

Morphological

analyser

Structured

electronic

dictionaries

Surface syntax

parser

Word-sense

disambiguation

Lexical

Database

_Corpus

(22)

What not to

do (III)

l

When you complete a new resource or tool do

not keep it to yourself

–

many researchers in the world are investigating on

English, but only a few on each minority language

–

we will not become rich (market criteria do not

usually apply)

J

è

Results should be public and shared for

research purposes.

(23)

Conclusions

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Long-term strategy for research and development of

language engineering.

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Based on the experience of the IXA Group on the

automatic processing of Basque.

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Every foundation, tool, and application developed in

the previous phases is of great importance to face

new problems and challenges.

l

The development of a sound language industry should

be the result of a coordinated effort, involving

research groups, institutions and industry.