Showing papers on "Semantic similarity published in 1987"

Semantic database modeling: survey, applications, and research issues

Abstract: Most common database management systems represent information in a simple record-based format. Semantic modeling provides richer data structuring capabilities for database applications. In particular, research in this area has articulated a number of constructs that provide mechanisms for representing structurally complex interrelations among data typically arising in commercial applications. In general terms, semantic modeling complements work on knowledge representation (in artificial intelligence) and on the new generation of database models based on the object-oriented paradigm of programming languages.This paper presents an in-depth discussion of semantic data modeling. It reviews the philosophical motivations of semantic models, including the need for high-level modeling abstractions and the reduction of semantic overloading of data type constructors. It then provides a tutorial introduction to the primary components of semantic models, which are the explicit representation of objects, attributes of and relationships among objects, type constructors for building complex types, ISA relationships, and derived schema components. Next, a survey of the prominent semantic models in the literature is presented. Further, since a broad area of research has developed around semantic modeling, a number of related topics based on these models are discussed, including data languages, graphical interfaces, theoretical investigations, and physical implementation strategies.

Categories of knowledge. Further fractionations and an attempted integration.

Abstract: In this study we investigated the category specificity of the comprehension impairments of Y.O.T., a patient with a severe global dysphasia. Using matching to sample techniques it was possible to demonstrate selective impairments and selective preservations not only of broad categories of semantic knowledge but also of particular subsets of such categories. Specifically, Y.O.T.'s comprehension of 'objects' was, in general, significantly more impaired than for foods or living things. Within the broad class of objects she was significantly more impaired in the comprehension of small manipulable objects than large man-made objects. Within her proper noun vocabulary there was a significant dissociation between her good comprehension of proper nouns having a unique and well-known referent (e.g., Churchill) and common proper nouns without such a referent (e.g., Jones). Her error responses were not consistent, semantic similarity and significant rate effects were observed, and it was therefore considered that her category specific comprehension deficits were primarily ones of access to a full semantic representation. We attempt to give a principled account of the increasing number of seemingly arbitrary instances of fine-grain categorical impairments of semantic knowledge. We have suggested that different weighting values from multiple sensory channels will be important in the acquisition of different categories of knowledge and that such differential weightings could be the basis of the categorical organization of systems in the brain subserving semantic knowledge.

Semantic Interpretation and the Resolution of Ambiguity

Abstract: Preface 1. Introduction 2. Semantic interpretation 3. The Absity semantic interpreter 4. Lexical disambiguation 5. Polaroid words 6. Structural disambiguation 7. The semantic enquiry desk 8. Conclusion 9. Speculations, partially baked ideas, and exercises for the reader References Index of names Index of subjects.

Characterizing attentional resources.

Abstract: Other studies have found that it is easier to divide attention when messages can be discriminated on the basis of stimulus and response features. The present study extended these results and explored whether dual-task performance is a function of similarity of central processing and, more specifically, the semantic similarity of the competing messages. In a dichotic listening task, subjects detected targets in concurrent messages that either differed semantically and required different central processing (the mixed condition) or were semantically similar and required similar central processing (the same condition). Three criteria are developed to determine whether the tasks in the mixed condition call upon distinct resources. The results are discussed in terms of three metaphors for resources: fuel, structure, and skills. (PsycINFO Database Record (c) 2012 APA, all rights reserved) Keywords: Driver distraction; Language: en

Lexical Constraints on Syntactic Acquisition

Abstract: This paper investigates what has traditionally been viewed as syntactic acquisition, with the goal of questioning whether what appears to be syntactic acquisition is more appropriately described as lexical or semantic acquisition. Data come from responses to a grammaticality judgment test by learners of English as a second language at two proficiency levels. Four syntactic structures were examined. The sentences tested varied in the verbs used (e.g., John donated/gave Mary a present; John donated/gave a present to Mary). The results suggest that less proficient subjects use syntactic strategies, more proficient learners use more semantic based strategies, and there is more lexical differentiation at the lower levels of proficiency. Thus, as learners gain in proficiency, there is an increased influence of the semantic relatedness of lexical items.

A structured representation of word-senses for semantic analysis

Abstract: A framework for a structured representation of semantic knowledge (e.g. word-senses) has been defined at the IBM Scientific Center of Roma, as part of a project on Italian Text Understanding. This representation, based on the conceptual graphs formalism [SOW84], expresses deep knowledge (pragmatic) on word-senses. The knowledge base data structure is such as to provide easy access by the semantic verification algorithm. This paper discusses some important problem related to the definition of a semantic knowledge base, as depth versus generality, hierarchical ordering of concept types, etc., and describes the solutions adopted within the text understanding project.

Does charm need depth? Similarity and levels-of-processing effects in cued recall.

Abstract: Eich {1985) recently presented a distributed memory model in which the pattern of results used to support the levels-of-processing view of Craik and Lockhart (1972) was modeled by different degrees of similarity between the encoding context and the to-be-recalled item. We report two experiments in which both phonemic and semantic similarity were varied between pairs of words and incidental acquisition (rhyme vs. category judgments) was varied across the same pairs of items. In both experiments the manipulation of the acquisition task produced a difference in cued-recall performance for positive and negative rhyme and category judgments. Recall was better following a category encoding decision than following a rhyme decision. This difference was independent of the effects of similarity, which demonstrated that Eich*s (1985) assumptions regarding the effects of similarity are not sufficient to account for the differences resulting from the manner in which subjects encode information. An alternative method of modeling the levels-of-processing effect within the framework of distributed memory models is proposed. The levels-of-processing approach has been an influential framework for research in human memory since Craik and Lockhart's seminal (1972) paper. According to the levels-ofprocessing view, memory for events is determined by the type of processing that is performed on the to-be-encoded material. Recently, Eich (1985) has offered a different theoretical interpretation of the typical results used to support the levels of processing framework. According to Eich's view, differences in memory performance between encoding conditions result from differences in the degree of similarity between the target items and their respective context. The present article contrasts the levels-of-processing approach with Eich's similarity hypothesis and reports an empirical investigation that pits these two views against each other.

Boolean Interpretation of Conjunctions for Document Retrieval.

Abstract: It is generally recognized that the conjunction “and” plays an ambiguous role in natural language. When considered within the domain of Boolean document retrieval, this ambiguity makes the automatic Boolean interpretation of statements representing information needs a difficult task. The human analyst is able to resolve this ambiguity with relative ease. However, the processes employed appear complex and are not well understood. This article examines a semantic property of the conjunction, i.e., the semantic similarity between the conjuncts with a view to automatically resolving this ambiguity. Specifically, the idea examined is that if the two conjuncts are semantically similar then the conjunction is best interpreted as a Boolean OR, otherwise as an AND. The study resulted in an algorithm which utilizes semantic information and some syntactic information (both of which are derivable from a standard dictionary) to obtain the appropriate Boolean interpretation. The algorithm was successful when evaluated against human decisions. In addition to contributing the algorithm, this article draws attention to the effects of this ambiguity on the derivation of appropriate Boolean search specifications from natural‐language statements representing information needs. © 1987 John Wiley & Sons, Inc.

Utterance Generation from Semantic Representations Augmented with Pragmatic Information

Abstract: This chapter reports on an exploration of the problems and possibilities of the automatic generation of natural language utterances from formal semantic/pragmatic representations, using the syntactic, semantic and pragmatic formalisms developed for natural language interpretation in the context of the TENDUM dialogue system (Bunt et al., 1985). The three formalisms have explicitly been designed to support one another, and present a highly formalized approach to each of the areas concerned: syntax, semantics, and pragmatics. The syntactic formalism is a kind of (generalized) phrase-structure grammar that allows discontinuous constituents: it is motivated by the aim of obtaining semantic and pragmatic interpretations in a systematic way. The semantic formalism applies the methods of model-theoretic semantics while keeping general and specific world knowledge in separate models. The pragmatic formalism can be viewed as a formalization, in model-theoretic terms, of a variant of speech act theory based on context-changing functions. The combination of these formalisms has proved successful for the interpretation of natural language expressions in the context of an information dialogue and has been implemented in the TENDUM dialogue system.

Semantic collating device

Abstract: PURPOSE:To execute a retrieval for selecting all documents having desired contents and selecting an unnecessary document by decreasing it to the utmost, by calculating a semantic similarity between different representations. CONSTITUTION:When one pair of representations (a retrieval condition, an object to be retrieved) are inputted, a structure analyzing means 1 analyses their structure and represents a semantic structure. A word level similarity calculating means 2 utilizes a word collection which has stored a semantic similarity between words being in a role corresponding to each other in a storage means 3, with regard to all block pairs in one pair of semantic structure which are obtained by the structure analyzing means concerned 1. A block level similarity calculating means 4 calculates a semantic similarity from the sum total of the semantic similarity between the words which are obtained, and the upper limit value of the sum total which can be reached. Subsequently, by a result of them, a block pair having the highest similarity is decided, and the similarity of th block pair is outputted as the semantic similarity between the retrieval condition and the object to be retrieved, together with information for discriminating the block pair.

Syntactic Representation and Semantic Interpretation

Abstract: It is generally hypothesized that syntactic representations have “psychological reality” that is, the cognitive system, in processing strings of words, assigns to each a unique syntactic structure which is the input to semantic interpretation. A criterion by which one can evaluate a syntactic theory is thus whether or not a semantic representation can be derived from it by algorithms. The issue is interesting beyond linguistic theory to cognitive science in general, because the syntactic structures assigned are dependent on the workings of the relevant part of the brain. Furthermore, because these syntactic structures are semantically interpreted, we gain insight into a particular system—the linguistic one—for encoding meaning and knowledge in the brain.