GATE, a General Architecture for Text Engineering

http://gate.ac.uk/ http://nlp.shef.ac.uk/

Hamish CunninghamDepartment of Computer Science, University of Sheffield

ENST, Paris, 20/1/2003

Natural Language Engineering in Sheffield:• One of the largest Human Language Technology groups in the EU• 50 staff in Language and Speech Processing; 25 in Information

Retrieval, including 6 professors • A focus on scientific method in AI (participate in all the leading

quantitative evaluation programmes in the US)• A focus on engineering high-quality open-source software for

applications and demonstrators

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GATE, a General Architecture for Text Engineering

GATE is….• An architectureA macro-level organisational picture for LE software systems. • A frameworkFor programmers, GATE is an object-oriented class library that implements the architecture. • A development environmentFor language engineers, computational linguists et al, GATE is a graphical development environment bundled with a set of tools for doing e.g. Information Extraction. • Free software (LGPL). Mature robust software (in development since 1995). Download at http://gate.ac.uk/download

Comes with…• Some free components... ...and wrappers for other people's components • Tools for: evaluation; visualise/edit; persistence; IR; IE; dialogue; ontologies; etc.

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                            Applications; languagesGATE has been used for a variety of applications, including:

• MUMIS: automatic creation of semantic indexes for multimedia programme material

• MUSE: a multi-genre IE system

• EMILLE: a 70 million word corpus of Indic languages

• Metadata for Medline (at Merck)

• Creation of metadata for Semantic Web Services; documentation using NLG

• HSE: summarisation of health and safety information from company reports

• OldBaileyIE: NE recognition on 17th century Old Bailey Court reports.

• AKT: language technology in knowledge management

• AMITIES: call centre automation

• Digital libraries / e-philology for ancient languages researchers

• Various Medical Informatics and database technology projects

• IE in Romanian, Bulgarian, Greek, Bengali, Spanish, Swedish, German, Italian, and

French (Arabic, Chinese and Russian next year)

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Some users…At time of writing a representative fraction of GATE users includes:• Longman Pearson publishing, UK; • BT Exact Technologies, UK;• Merck KgAa, Germany; • Canon Europe, UK; • Knight Ridder (the second biggest US news publisher); • BBN Technologies, US;• Sirma AI Ltd., Bulgaria; • Resco AB, Sweden/Finland/Germany;• Glaxo Smith Kline Plc: drug-based navigation of Medline abstracts• Master Foods NV: extraction of commodities events from news• the American National Corpus project, US; • Imperial College, London, the University of Manchester, Queen Mary

College, UMIST, the University of Karlsruhe, Vassar College, ISI / the University of Southern California and a large number of other UK, US and EU Universities;

• the Perseus Digital Library project, Tufts University, US.

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Architectural principles• Non-prescriptive, theory neutral (strength and weakness) • Re-use, interoperation, not reimplementation (e.g. diverse XML support, integration of tools like Protégé, Jena and Weka) • (Almost) everything is a component, and component sets are user-extendable

Component-based development• An OO way of chunking software: Java Beans • GATE components: CREOLE = modified Java Beans (Collection of REusable Objects for Language Engineering) • The minimal component = 10 lines of Java, 10 lines of XML, 1 URL.

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GATE Language ResourcesGATE LRs are documents, ontologies, corpora, lexicons, ……

Documents / corpora:• GATE documents loaded from local files or the web... • Diverse document formats: text, html, XML, email, RTF, SGML.

Processing ResourcresAlgorithmic components knows as PRs – beans with execute methods.• All PRs can handle Unicode data by default. • Clear distinction between code and data (simple repurposing).• 20-30 freebies with GATE• e.g. Named entity recognition; WordNet; Protégé; Ontology; OntoGazetteer; DAML+OIL export; Information Retrieval based on Lucene

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Vis

ual

Res

ourc

es

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Displaying Coreference Information

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Displaying Syntactic Information

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Lexicon Support – WordNet example

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Relational Database

…

GA

TE

Form

at Handlers

HTMLdocs

RTFdocs

XMLdocs

Named entity

Core-ference

…

ANNIE

POS tagger

Named entity

Eventextraction…

Custom application 1

…Document content

Document metadata

Document format data

Linguistic data

File storage

…

Oracle/PostgresQL

A Language AnalysisExample

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Building IE Components in GATE (1)The ANNIE system – a reusable and easily extendable set of components

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 Building IE Components in GATE (2)

JAPE: a Java Annotation Patterns Engine • Light, robust regular-expression-based processing • Cascaded finite state transduction • Low-overhead development of new components

Rule: Company1 Priority: 25 ( ( {Token.orthography == upperInitial} )+ {Lookup.kind == companyDesignator} ):companyMatch --> :companyMatch.NamedEntity = { kind = company, rule = “Company1” }

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 Performance Evaluation

• At document level – annotation diff

• At corpus level – corpus benchmark tool – tracking system’s performance over time

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Regression Testing – Corpus Benchmark Tool

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GATE is being used for development of (semi-)automatic methods for:

• linking web pages to Ontologies using Information Extraction;

• learning and evolving Ontologies via IE and lexical semantic network traversal.

The Semantic Web and GATE

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Populating Ontologies with IE

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Protégé and Ontology Management

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Information Retrieval SupportBased on the Lucene IR engine

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GATE Unicode Kit (GUK) Java provides no special support for text input (this may change)

• Support for defining additional Input Methods (IMs)

• currently 30 IMs for 17 languages

• Pluggable in other applications

Editing Multilingual Data

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Processing Multilingual DataAll the visualisation and editing tools for ML LRs use enhanced Java facilities:

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Dialogue Systems

• GATE is being used in the Amities project for automating call centres• Creation of dialogue processing server components to run in the Galaxy Communicator architecture• Easy adaptation of the portable IE components to work on noisy ASR output • Robustness and speed of GATE components vital for real-time dialogue systems

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The MUMIS project

• Multimedia Indexing and Searching Environment • Composite index of a multimedia programme

from multiple sources in different languages• ASR, video processing, information extraction

(Dutch, English, German), merging, user interface• University of Twente/CTIT, University of Sheffield,

University of Nijmegen, DFKI, MPI, ESTEAM AB, VDA• Yorick Wilks, Hamish Cunningham, Horacio Saggion,

Kalina Bontcheva, Diana Maynard, Oana Hamza, Cristian Ursu

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The Whole Picture

EN

DE FormalText

FormalText

FormalTextFormal

TextFormal

TextFormal

TextFormalText

FormalText

FormalTextText

Sources

IE

IE

IE

NL

FormalText

FormalText

FormalTextFormalText

FormalText

FormalTextFormalText

FormalText

FormalText

Transcriptions

ASR

Formal

Text

Formal

Text

Formal

Text

Formal

Text

Formal

Text

Formal

Text

Formal

Text

Formal

Text

Formal

Text

Formal

Text

Formal

Text

SpeechSignals

Merging Final Annotations

Formal

Text

Formal

TextForma

lText

Anno-tations

MultimediaData Base

Video & AudioSignal

UserInterface

Query

Results

Ontology & Lexicon

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User Interface

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Play

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Conclusion

GATE: an infrastructure that lowers the overhead of creating & embedding robust NLP components

Further information: http://gate.ac.uk/

• Online demos, tutorials and documentation• Software downloads• Talks and papers