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LELA300431 Language and Computers. Harold Somers Professor of Language Engineering. Computers and Language?. Getting computer to handle language in a natural way As part of interface with user (eg alternatives to keyboard/mouse input, text output, support for the disabled)
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LELA300431Language and Computers Harold Somers Professor of Language Engineering
Computers and Language? • Getting computer to handle language in a natural way • As part of interface with user (eg alternatives to keyboard/mouse input, text output, support for the disabled) • consulting databases to get information (e.g. library catalogue, train timetable, banking) • As a task in itself: specifically linguistic purposes (e.g. dictation, translation, summarizing, report writing, language teaching) • Using computer to “do” linguistics • Synonyms (or components?) • Natural Language Processing • Computational Linguistics • Language Engineering • Basic tools, techniques and models • Applications
Syllabus • Survey of applications • Elements of language, levels of linguistic processing • Sound (speech recognition, synthesis) • Writing (OCR, handwriting, character sets, spelling) • Words (lexicon, morphology) • Sentences (syntax) • Semantics, Pragmatics • Branches of language/linguistics • Psycholinguistics and AI • Applied linguistics (teaching, translation) • Information retrieval • Or: your choice of anything else relevant (historical, socio, etc.)
Assessment Examination: 50 multiple choice (or short phrase) answers Essay – 3000 word essay due in at the start of the exam period • Choose a particular NLP application, and explain the difficulties that natural language poses to the computer, and how (or whether) they are addressed. • How is the study of language relevant to NLP? Focus on one or two areas of NLP only. • Choose one branch of language study (eg historical, sociolinguistics, psycholinguistics, child language, applied linguistics, etc.) and discuss what role the computer, and in particular computational linguistics, could play. (Note that all involve taking lectures as starting point, and going into more detail, based on your own “research”)
Philosophy Logic HCI Computer Science NLP Artificial Intelligence Phonetics Signal Processing Psychology Electrical Engineering Language Engineering What is NLP? Language and Linguistics
Language and AI • “language ability” is an integral part of Artificial Intelligence, which relates to robotics • Computers in SciFi use language readily: how realistic is this? What are the problems? • HAL in “2001: A Space Odyssey” (1968)
How realistic is HAL? Non-linguistic functions include... • monitoring and controlling the spaceship • playing chess • vision • general reasoning about the world … • especially this particular mission
HAL’s use of language He has to use language to communicate with the crew, including ... • chatting sociably • discussing general and specific conditions in the spaceship • understanding commands • initiating conversations, whether “work” or “play”
What is language? • spoken vs. written language • speaker vs. hearer = production vs. analysis • different levels of language • different functions of language
Computer speech • for natural-sounding speech, computer must get individual sounds right, but also combine them correctly • intonation • stress (pitch, loudness, length) • pace (pauses can be significant)
Speech understanding • signal processing (acoustic physics) • separating speech from background noise • recognizing individual speech sounds (humans can make very fine distinctions) It’s hard to wreck a nice beach What dime’s a neck’s drain to stop port? • variability in human voices
Problems with language in general • Words are ambiguous (bank, round, take) • Sentences are ambiguous The chicken is ready to eat Visiting relatives can be boring End to free school looms The man saw the girl with a telescope Remove bulb, cover, and replace
Pragmatic problems • We don’t always say what we mean Can you pass the salt? It’s cold in here, isn’t it? I’m sorry (= Say it again) Do you want some more? You’re alright. • We don’t always mean what we say It’s raining cats and dogs I could murder a sandwich
Solutions • Linguistics (“grammar”) can often tell us which interpretations are possible, including limited aspects of meaning, e.g. The man saw the girl with a hat • Restricted domain: if we know what the subject is, a lot of ambiguity disappears Context Real-world knowledge
Next up • A whistle-stop tour of applications and what they involve • Then down to business!