胡壮麟 语言学教程修订版 课堂笔记和讲义精选Chapter (10)

Chapter 10 Language and ComputerWhat is computational linguistics?Computational linguistics is a branch of applied linguistics, dealing with computer processing of human language.(1) It includes the analysis of language data so as to establish the order in which learnersacquire various grammatical rules or the frequency of occurrence of some particularitem.(2) It includes electronic production of artificial speech and the automatic recognition ofhuman speech.(3) It includes research on automatic translation between natural languages.(4) It also includes text processing and communication between people and computers. 10.1 Computer-assisted language learning (CALL)10.1.1 CAL / CAI vs. CALLCAI (Computer-assisted instruction) means the use of a computer in a teaching program. CAL (Computer-assisted learning) refers to the use of a computer in teachingand learning and in order to help achieve educational objectives. CAI aims at seeingeducational problems on the part of the teacher, whereas CAL emphasizes the use of acomputer in both teaching and learning. CALL (Computer-assisted language learning)means the use of a computer in the teaching or learning of a second or foreign language.If CAI or CAL deals with teaching and learning problems in general, CALL deals withlanguage teaching and learning in particular.10.1.2 Phases of CALL development (4 periods)1. During this period, computers were large mainframe machines kept inresearch institutions.2. Small computers appeared and cost cheaper than before, which made ageneration of programs possible.3. The learning was not so much supplied by the language of the text itself as bythe cognitive problem-solving techniques and the interaction between studentsin the group.4. Instead of writing specific programs for language teaching, word-processinghas adapted to language teaching by enabling students to compose and try ourtheir writings in a non-permanent form.10.1.3 Technology1. Customizing, template, and authoring programs.2. Computer networks.3. Compact disk technology4. Digitized sound.10.2 Machine translation (MT)10.2.1 History of development1. The independent work by MT researchers2. Towards good quality output3. The development of translate tools10.2.2 Research methods1. Linguistic approach2. The practical approaches(1) The transfer approach(2) The inter-lingual approach(3) Knowledge-based approach10.2.3 MT Quality10.2.4 MT and the Internet10.2.5 Spoken language translation10.2.6 MT and human translationAt the beginning of the new century, it is apparent that MT and human translation can and will co-exist in relative harmony. Those skills which the human translators cancontribute will always be in demand.(1) When translation has to be of “publishable” quality, both human translation andMT have their roles. MT plays an important part in large scale and rapid translation ofboring technical documentation, highly repetitive software localization manuals, andmany other situations where the costs of human translation are much higher than theones of MT. By contrast, the human translators are and will remain unrivalled fornon-repetitive linguistically sophisticated texts (e.g. in literature and law), and even forone-off texts in specific highly-specialized technical subjects.(2) For the translation of texts where the quality of output is much less important,MT is often an ideal solution.(3) For the one-to-one interchange of information, there will probably always be arole for the human translators. But for the translation of personal letters, MT systemsare likely to be increasingly used; and, for electronic mail and for the extraction ofinformation from web pages and computer-based information services, MT is the onlyfeasible solution.(4) As for spoken translation, there must surely always be a market for the humantranslators. But MT systems are opening up new areas where human translation hasnever featured: the production of draft versions for authors writing in a foreign language,who need assistance in the translation of information from databases; and no doubt,more such new applications will appear in the future as the global communicationnetworks expand and as the realistic usuality of MT becomes familiar to a wider public.10.3 Corpus linguistics10.3.1 Definition1. Corpus (pl. corpora): A collection of linguistic data, either compiled as writtentexts or as a transcription of recorded speech. The main purpose of a corpus isto verify a hypothesis about language –for example, to determine how theusage of a particular sound, word, or syntactic construction varies.2. Corpus linguistics: Corpus linguistics deals with the principles and practice ofusing corpora in language study. A computer corpus is a large body ofmachine-readable texts.10.3.2 Criticisms and the revival of corpus linguistics10.3.3 Concordance10.3.4 Text encoding and annotation1. It should be possible to remove the annotation from an annotated corpus inorder to revert to the raw corpus.2. It should be possible to extract the annotation by themselves from the text.3. The annotation scheme should be based on guidelines which are available tothe end user.4. It should be made clear how and by whom the annotation was carried out.5. The end user should be made aware that the corpus annotation is not infallible,but simply a potentially useful tool.6. Annotation schemes should be based as far as possible on widely agreed andtheory-neutral principles.7. No annotation scheme has a priori right to be considered as a standard.10.3.5 The roles of corpus data1. Speech research2. Lexical studies3. Semantics4. Sociolinguistics5. Psycholinguistics10.4 Information retrieval (IR)10.4.1 Scope defined10.4.2 An information retrieval system10.4.3 Three main areas of research1. Content analysis2. Information structure3. Evaluation10.5 Mail and news。