Showing papers on "Natural language published in 1978"

Introduction to formal language theory

Abstract: From the Publisher: Formal language theory was fist developed in the mid 1950's in an attempt to develop theories of natural language acquisition. It was soon realized that this theory (particularly the context-free portion) was quite relevant to the artificial languages that had originated in computer science. Since those days, the theory of formal languages has been developed extensively, and has several discernible trends, which include applications to the syntactic analysis of programming languages, program schemes, models of biological systems, and relationships with natural languages.

PRUF—a meaning representation language for natural languages

Abstract: PRUF—an acronym for Possibilistic Relational Universal Fuzzy—is a meaning representation language for natural languages which departs from the conventional approaches to the theory of meaning in several important respects. First, a basic assumption underlying PRUF is that the imprecision that is intrinsic in natural languages is, for the most part, possibilistic rather than probabilistic in nature. Thus, a proposition such as “Richard is tall” translates in PRUF into a possibility distribution of the variable Height (Richard), which associates with each value of the variable a number in the interval [0,11 representing the possibility that Height (Richard) could assume the value in question. More generally, a proposition, p , translates into a procedure, P, which returns a possibility distribution, Π p , with P and Π p representing, respectively, the meaning of p and the information conveyed by p . In this sense, the concept of a possibility distribution replaces that of truth as a foundation for the representation of meaning in natural languages. Second, the logic underlying PRUF is not a two-valued or multivalued logic, but a fuzzy logic, FL, in which the truth-values are linguistic, that is, are of the form true, not true, very true, more or less true, not very true , etc., with each such truth-value representing a fuzzy subset of the unit interval. The truth-value of a proposition is defined as its compatibility with a reference proposition, so that given two propositions p and r, one can compute the truth of p relative to r . Third, the quantifiers in PRUF—like the truth-values—are allowed to be linguistic, i.e. may be expressed as most, many, few, some, not very many, almost all, etc. Based on the concept of the cardinality of a fuzzy set, such quantifiers are given a concrete interpretation which makes it possible to translate into PRUF propositions exemplified by “Many tall men are much taller than most men,” “All tall women are blonde is not very true,” etc. The translation rules in PRUF are of four basic types: Type I—pertaining to modification; Type II—pertaining to composition; Type III—pertaining to quantification; and Type IV—pertaining to qualification and, in particular, to truth qualification, probability qualification and possibility qualification. The concepts of semantic equivalence and semantic entailment in PRUF provide a basis for question-answering and inference from fuzzy premises. In addition to serving as a foundation for approximate reasoning, PRUF may be employed as a language for the representation of imprecise knowledge and as a means of precisiation of fuzzy propositions expressed in a natural language.

An English language question answering system for a large relational database

Abstract: By typing requests in English, casual users will be able to obtain explicit answers from a large relational database of aircraft flight and maintenance data using a system called PLANES. The design and implementation of this system is described and illustrated with detailed examples of the operation of system components and examples of overall system operation. The language processing portion of the system uses a number of augmented transition networks, each of which matches phrases with a specific meaning, along with context registers (history keepers) and concept case frames; these are used for judging meaningfulness of questions, generating dialogue for clarifying partially understood questions, and resolving ellipsis and pronoun reference problems. Other system components construct a formal query for the relational database, and optimize the order of searching relations. Methods are discussed for handling vague or complex questions and for providing browsing ability. Also included are discussions of important issues in programming natural language systems for limited domains, and the relationship of this system to others.

The acquisition and development of language by bilingual children

Abstract: Analysing the gradual learning process through which a child becomes bilingual from early infancy, three stages can be distinguished: (1) the child has one lexical system which includes words from both languages; (2) the child distinguishes two different lexicons but applies the same syntactic rules to both languages; (3) the child has two linguistic codes, differentiated both in lexicon and in syntax, but each language is exclusively associated with the person using that language. Only at the end of this stage, when the tendency to categorize people in terms of their language decreases, can one say that a child is truly bilingual.

The monitor model: some methodological considerations

Abstract: The Monitor Model has been proposed (Krashen 1975, 1977a) as a general model for adult second-language performance. The model claims that adult second-language performers have two means of internalizing the rules of a target language: (1) language acquisition, which is primarily subconscious, is not influenced by overt teaching or error correction, and is very similar to primary language acquisition in children; (2) language learning, which involves the conscious representation of pedagogical rules, and is influenced by teaching and error detection. The model hypothesizes that learning is available to the adult second-language performer only as a Monitor—that is, people use conscious grammar only to alter the output of the acquired system. This paper examines the Monitor Model and presents a methodological critique of the research on which the model is based. An attempt is made to provide an outline of an alternate model that more parsimoniously accounts for the data and that ties into a theory of human information processing generally.

A Practical Guide to the Teaching of English As a Second or Foreign Language

Abstract: A practical guide to the teaching of English as a second or foreign language , A practical guide to the teaching of English as a second or foreign language , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

Language and Situation: Language Varieties and their Social Contexts

Abstract: Originally published in 1978. This book provides and explains a framework for understanding and describing variations of style of language in relation to the social context in which it is used. Constant features of language users, such as their temporal, geographical. and social origins, their range of intelligibility, and their individualities, are related to concepts of dialects, but dialects are not the only kind of language variety. There are features of language situations that yield others; the medium used, the roles of the users and their relationships, as well as recurring situations and cultural habits, all relate to the style employed. Variety in language can be seen in terms of the major functions of language, as 'content' as 'inter-action' and as 'texture'. Studying variety in language from sociological and linguistic aspects this book is also interesting for psycholinguistics and literary study.

Natural Language Access To A Melanoma Data Base

Abstract: This paper describes ongoing research towards developing a system that will allow physicians personal accesa to patient medical data through natural language queries to support both patient management and clinical research. A prototype system has been implemented for a small data base on malignant melanoma. The physician can input queries in English that retrieve specified data for particular patients or for groups of patients satisfying certain characteristics, that perform simple calculations, that allow browsing through the data base, and that assist in identifying relations among attributes. The system supports dialogue interactions; that is, the user can follow a line of inquiry to test a particular hypothesis by entering a sequence of queries that depend on each other. Classes of questions that can be processed are described and examples using the system are given.

Informality in Program Specifications

Abstract: This paper is concerned with the need for computer-based tools which help human designers formulate formal process-oriented specifications. It first determines some attributes of a suitable process-oriented specification language, then examines the reasons why specifications would still be difficult to write in such a language in the absence of formulation tools. The key to overcoming these difficulties seems to be the careful introduction of informality based on partial, rather than complete, descriptions and the use of a computer-based tool that uses context extensively to complete these descnrptions during the process of constructing a well-formed specification. Some results obtained by a running prototype of such a computer-based tool on a few informal example specifications are presented and, finaliy, some of the techniques used by this prototype system are discussed.

Implication Reversal in a Natural Language

Abstract: Much recent work about language has been representational: the solution of particular problems and the account of linguistic distributions is often perceived as being the choice (or the discovery) of abstract representations (e.g., semantic, syntactic, logical…) which reflect directly, largely by means of their configurations, properties and generalizations only dimly apparent at the ‘surface’. Of course, rules are necessary to relate these representations to the actually observed manifestations of language and the form of these rules, like that of the representations, is considered to be a question of crucial importance in linguistic theory.

Recognition of continuously read natural corpus

Abstract: Preliminary results have been obtained with a system for recognizing continuously read sentences from a naturally-occurring corpus (Laser Patents), restricted to a 1000-word vocabulary. Our model of the task language has an entropy of about 4.8 bits/word and a perplexity of 21.11 words. Many new problems arise in recognition of a substantial natural corpus (compared to recognition of an artificially constrained language). Some techniques are described for treating these problems. On a test set consisting of 20 sentences having a total of 486 words, there was a word error rate of 33.1%.

Formal Semantics and Pragmatics for Natural Languages

Abstract: Conditionals, Generic Quantifiers, and Other Applications of Subgames.- Ambiguous Coreference With Quantifiers.- Negative Coreference: Generalizing Quantification for Natural Language.- Syntactic Domains for Semantic Rules.- Variable Binding and Relative Clauses.- Adverbs of Space and Time.- Time Schemes, Tense Logic and the Analysis of English Tenses.- A System of Chronological Tense Logic.- Semantics versus Pragmatics.- Implication Reversal in a Natural Language.- Structure and Function of the Grammatical Component of the Text-Structure World-Structure Theory.- Questions and Answers in a Context-dependent Montague Grammar.- The Introduction of Truth Predicates into First-Order Languages.- List of Participants.

Natural Language Communication with Computers

Abstract: A formalism for the description of question answering systems.- Access to data base systems via natural language.- An overview of plidis a problem solving information system with German as query language.- Metamorphosis grammars.- The theory and practice of augmented transition network grammars.- Syntactic analysis of written Polish.

An Experimental Study of Children’s Ideas About Language

Abstract: From diary studies (see especially Kaper, 1959) as well as recent experiments, it has become clear that children reflect on language well before they receive any formal teaching in grammar: both spontaneously and in response to questions, they make remarks on pronounciation, on morphology, they correct other speakers, they remark on meaning and form, and they may even make puns. But do children also reflect on language in a more “philosophical” way? Do they have ideas about the special properties that make natural language unique as a means of communication and representation? Such metalinguistic activity can be considered within the general framework of cognitive activity for two reasons. First of all, language by its very nature is a product of human cognition as well as a representational system which the child has to reconstruct and learn to use. And secondly, the fact that language becomes an object of human thinking is one manifestation of the general structuring of knowledge that takes place during cognitive development.1

Natural Language Information Formatting: The Automatic Conversion of Texts to a Structured Data Base

Abstract: Publisher Summary The field of computerized language processing encompasses a wide range of goals and methodologies, ranging from such theoretical objectives as the modeling of human linguistic behavior and human language acquisition, to such goals as machine translation, natural language systems for man–machine communication, and speech recognition. What unites these varied endeavors is the need to come to grips with the special features of natural language as a communication system. The chapter approaches the problems from the viewpoint of information science, with applications envisioned primarily in science information retrieval and data base management. The chapter also attempts to provide a general solution to the following problem: Given a collection of documents on a particular subject written in English or another natural language, how can computer programs arrange the information contained in the documents so that it can be accessed from different points of view for a variety of informational tasks. This assumes that there are underlying common features in the texts that can be made explicit by formal procedures. For the field of information management the solution to this problem would extend the data bases on which data processing functions that have already been automated can operate. The chapter discusses the principles and methods of analysis, and computer programs for information formatting. If indeed it is possible to obtain structured data bases from textual material, then the potential for new computer applications is large. In this section a few applications are sketched with reference to how they would be realized on a data base of computer-formatted medical records.

Semantic network representations in rule-based inference systems1

Abstract: Rule-based inference systems allow judgmental knowledge about a specific problem domain to be represented as a collection of discrete rules. Each rule states that if certain premises are known, then certain conclusions can be inferred. An important design issue concerns the representational form for the premises and conclusions of the rules. We describe a rule-based system that uses a partitioned semantic network representation for the premises and conclusions. Several advantages can be cited for the semantic network representation. The most important of these concern the ability to represent subset and element taxonomic information, the ability to include the same relation in several different premises and conclusions, and the potential for smooth interface with natural language subsystems. This representation is being used in a system currently under development at SRI to aid a geologist in the evaluation of the mineral potential of exploration sites. The principles behind this system and its current implementation are described here.

Ngandi grammar, texts, and dictionary

Abstract: Reference grammar, texts, and short dictionary of the Ngandi language of eastern Arnhem Land, Australia.

Lexical ambiguity of words used in english text

Abstract: Lexical ambiguity is generally assumed to be widespread in natural languages but quantitative estimates have not been available. At least 32% of the words used in English text were found to be ambiguous in studies reported here. This figure is probably very conservative. Temporary word definitions established for special purposes occurred in 30% of a sample of texts.

Interpretation of natural language in an information system

Abstract: This paper discusses some of the linguistic problems encountered during the development of the User Specialty Languages (USL) system, an information system that accepts a subset of German or English as input for query, analysis, and updating of data. The system is regarded as a model for portions of natural language that are relevant to interactions with a data base. The model provides insight into the functioning of language and the linguistic behavior of users who must communicate with a machine in order to obtain information. The aim of application independence made it necessary to approach many problems from a different angle than in most comparable systems. Rather than a full treatment of the linguistic capacity of the system, details of phenomena such as time handling, coordination, quantification, and possessive pronouns are presented. The solutions that have been implemented are described, and open questions are pointed out.

Error-Correcting Parsers for Formal Languages

Abstract: This paper describes error-correcting parsers for context-free and context-sensitive languages with substitution, insertion and deletion errors. Furthermore, it is shown that the ability of the proposed parsers can be expressed in terms of the weighted Levenshtein metric.

Linguistic universals as evidence for empiricism

Abstract: I. Noam Chomsky turned the previously rather specialized discipline of linguistics into a subject of considerable general philosophical interest by his argument that the discovery of universal properties of natural language requires us to adopt a ‘nativist’ or ‘rationalist’ view of human mind – a view according to which ‘our systems of belief are those that the mind, as a biological structure, is designed to construct’ (Chomsky, 1976: 7). (I shall use the terms ‘nativism’ and ‘rationalism’ interchangeably in this article, since any difference we make between them is not important in the context of Chomsky's work. The truth is that, as with many philosophical ‘isms’, the two words do duty for a range of many more than two closely related, partly overlapping theses.) When Chomsky began publishing, a widespread attitude to human language was that expressed by Martin Joos (1957: 96): ‘languages [can] differ from each other without limit and in unpredictable ways’. Chomsky claims that this is false: to quote one of his favourite examples, it is perfectly possible to imagine a language which forms yes/no questions simply by reversing the order of the words in the corresponding statements, yet in fact no natural language has a rule remotely like this (even though this rule seems rather simpler, in an absolute sense, than many of the rules which are found in natural languages). Human languages differ in some respects, but in other respects they are all cut to a common pattern. Much of Chomsky's and his followers' work consists of formulating and testing increasingly refined hypotheses about the precise limits within which natural languages may vary.

A scale of context sensitive languages: Applications to natural language

Abstract: The classes of languages Ti are defined, i being a natural number, for which it is proved that Ti is a proper subset of T i+1, and a proper subset of context-sensitive languages, if Ti is the set of all context-free languages and Ti+1 is the set of all possible translations from Ti by means of a so-called linear deterministic pushdown store transducer; the formal mechanism is close enough to the so-called functional generative description, which has already been applied to large subsets of natural languages.