Sofia April 27. 2006 Language Technology in the Information Society - Hot issues and open questions - Walther v.Hahn University of Hamburg Computer Science

Sofia April 27. 2006

Language Technology in the

Information Society- Hot issues and open

questions -

Walther v.Hahn

University of Hamburg • Computer Science Department

Natural Language Systems Group

WWW: http://nats-www.informatik.uni-hamburg.de/view/User/WaltherVHahn

E-Mail: vhahn@informatik, uni-hamburg.de


Language Processing is more than a Text Processor

Text Processing


What is „Real“ Text Technology?

Text Processing

Gestures

Corpora

Images

Tools

Web Applications

Cultures

Linguistics

Workflow

Technologies Domains

User profiles

Ontologies

Languages

Models and Society

System Type

Methods


Language Technology is only useful if …

• ‘text” comprises spoken and written utterances of the language (the linguistic definition):

– Borders between the two types blur in WWW texts.

• the processes have access to the semantics of texts:

– the meaning structure with lexical semantics and syntax, including reference,

• the processes have access to the pragmatics of texts:

– the intended action (plan) behind the utterance


Focus of Interest in Texts

• We are interested in the semantics and pragmatics of utterances, not only in linguistic features or logic description

• Semantics and pragmatics are dependent on the users‘ intentions not only literal word-

centered contents• The contents, not the wording counts

paraphrases are equivalent• Utterances are planned hearer-dependent actions

only helpful answers count• Utterances are situated reference is crucial• The coherence of utterances reveals the whole truth

Without deictic resolution a system is blind


Comparing and Translating Languages)

Multilingual text processes of any sort are never a linguistic problem alone; you can write rules about languages, but not about reference, ontologies or work flows. Many processing problems are still unsolved:

• Language is ambiguousI saw a man with a hat vs I saw a man with a telescope

• differences among languagesНяколко момчета и момичета отидоха на кино, но само на

двама от тях им хареса филма.Some boys and girls went to the cinema, but only two of them (the

boys!) liked the movie.• WritingIt is even difficult to recognize names in different writings (Galja or Galia?), depending on the transliteration or conceptualization

Zur Anzeige wird der QuickTime™ Dekompressor „TIFF (LZW)“

benötigt.


Multilingual Communication

10 Emerging Technologies That Will Change Your WorldTechnology

Review Febr 2004

– Universal Translation– Synthetic Biology– Nanowires– Bayesian Machine Learning– T-Rays– Distributed Storage– RNA Interference– Power Grid Control– Microfluidic Optical Fibers– Personal Genomics

It is hopeless to provide FAHQMT translations of - any text, - any text type, - any purpose, - any situation, - any person, by one single systemonly for the 380 European language pairs. But the need is real. What is the solution? Who is responsible for what?

It is hopeless to provide FAHQMT translations of - any text, - any text type, - any purpose, - any situation, - any person, by one single systemonly for the 380 European language pairs. But the need is real. What is the solution? Who is responsible for what?


Modern Methods

The case of Machine Translation shows:

• Homogenous systems have systematic problems– Rule based (problem: crashes with unknown phenomena of any sort)– Statistical (problem: the millions of rare examples, extralinguistic

parameters)• Hybrid systems

– A) hybrid technologies• Statistical / example based/ rule based/ menue based etc. translation

– B) hybrid in/out channels • text, • sound,• images, • gestures,• lip reading


Real-Life Background of Texts

• Text analysis is crucial for cooperation in a vast variety of communication types:

• Oral communication (politics, economy, touristics, private interests, ...)

• Written communication (publications, lyrics, e-mail, touristics, bills, legal texts, ...)

• Text and images (WWW, catalogues, museums, menues, advertizing of any type, ...)

• Texts and gestures (road information, slanders, touristics, explanations of any sort, ...)

• Text and facial expression (slander, irony, first aid, ...)


Why natural language at all?

1. CoverageNL is complete. Whatever you want to express, it is , in principle, possible within NL,

2. Vagueness

The use of vague expressions is a highly efficient method in human interaction and the basis for innovative thinking. It must be tackled by language technology in a pragmatic way, not only by logical mechanisms,

3. Abbreviations

In most realistic and complex query settings, NL is shorter than formal languages. NL is coherent over whole paragraphs without repeating given information again and again. Elliptical expressions are unambigous by virtue of the situation and shared knowledge.


The Value of „Soft“ Fields

• Computer application (thus, computer science) in some areas is shifting from numerical operations to intentional support of human action. The specification, however, is conveyed exclusively by texts,

• This requires the understanding of utterances as communicative and cooperative problem solving (John Searle‘s „How to do things with words“).

• Introducing computer technology in real life increasingly requires psychology, linguistics, sociology and other humanities instead of mathematics, logics and statistics, which today is included anyway in tools, class libraries or plug-ins.


Metalanguage and Evaluation

• Any occurence of natural language is a mixture of object language and metalanguage, Error messages by the machine or by the user have to cope with both levels. This is why user cannot correct a system by giving natural language examples or helpful hints. Moreover, very often the level distinction is implicite („rubbish!“).

• Evaluation modules for quality check within hybrid systems cannot be better than the modules of the system. Otherwise a programmer would change the system‘s operating directly.


Verbmobil


International Cooperation

• Language processing is always a mixture of transnational interests, languages and (commercial, political, ethical, ...) agents, according to import and export of knowledge.

• Some tasks are international (political, economical organizations),

• others are national (language description, analysis of utterances, corpora, culture, ethics).

• In the future, EU will support pivot languages insted of 380 language pairs and every country will need to define their knowledge import and export budget and who pays for it (tax payers, companies, foundations, sponsors)


Obsolete Approaches

• FAHQ Analyis

• Isolated Systems

• Systems for all Languages

• Systems for all Domains

• Monomethodic Systems

• „The unknown trick“


The Sustainability Issue

Example:

• The digital satellite images of the rain forest from the 70ies in South America are not readable any more and can not be reconstructed by any method. They are lost for ever.


Maintenance and Conservation of Digital Documents

means

• „Refreshing“: To copy the document from media to media to keep the bit sequence. This is technically trivial.

• „Migration of content“: Conservation of the contents independently of the original perception

• “Migration of perception“: Conservation of the identical or very similar visual/acoustic surface.


Maintenance of Perception

Display 2106

Operating System 2106

Machine 2106

Document 2106

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Possible Solutions

• Producing paper copies, but losing programes, games, MM presentations, etc.

• Museum Approach: Keeping a machine of every new type with OS, programming languages etc. Not realistically viable (spare parts, operating knowledge, ...), extremely expensive.

• Emulation Approach: software emulation of software and OS, a long term task.

• Universal Virtual Approach: Constructing a virtual machine for the simulation of all existing machines and operating systems, extremely expensive.

• „Stone of Rosetta“-Approach: Keeping the bit sequence and producing an exact specification of the formal features of the document, the operating system and the machine. The local effort is small, but reconstruction is extremly expensive.


Emulation Approach

Display 2006


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2006-Emulator 2106

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Conclusion

• We have gained a lot of partial knowledge about language and language use, which may be sufficient for rather specific applications, however,

• we are taking the parts for the whole,

• we expect users to adapt to our technologies,

• we define the processing tasks by the cases we can handle,

• we still define text analysis in the paradigm of the 80ies.