1、BSI Standards Publication PD ISO/TS 24617-5:2014 Language resource management Semantic annotation framework (SemAF) Part 5: Discourse structure (SemAF-DS)PD ISO/TS 24617-5:2014 PUBLISHED DOCUMENT National foreword This Published Document is the UK implementation of ISO/TS 24617-5:2014. The UK partic
2、ipation in its preparation was entrusted to Technical Committee TS/1, Terminology. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its
3、 correct application. The British Standards Institution 2014. Published by BSI Standards Limited 2014 ISBN 978 0 580 84556 7 ICS 01.020 Compliance with a British Standard cannot confer immunity from legal obligations. This Published Document was published under the authority of the Standards Policy
4、and Strategy Committee on 31 March 2014. Amendments issued since publication Date Text affectedPD ISO/TS 24617-5:2014 ISO 2014 Language resource management Semantic annotation framework (SemAF) Part 5: Discourse structure (SemAF-DS) Gestion de ressources langagires Cadre dannotation smantique (SemAF
5、) Partie 5: Structures de discours (SemAF-DS) TECHNICAL SPECIFICATION ISO/TS 24617-5 First edition 2014-03-01 Reference number ISO/TS 24617-5:2014(E)PD ISO/TS 24617-5:2014ISO/TS 24617-5:2014(E)ii ISO 2014 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2014 All rights reserved. Unless otherwise
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7、 or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in SwitzerlandPD ISO/TS 24617-5:2014ISO/TS 24617-5:2014(E) ISO 2014 All rights reserved iii Cont
8、ents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references 1 3 T erms and definitions . 1 4 Overview . 2 5 Segment structure . 3 6 Content structure . 4 7 Mapping between segment and content structures . 7 8 Concluding remarks .16 Bibliography .17PD ISO/TS 24617-5:2014ISO/TS 24617-5:201
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15、information The committee responsible for this document is ISO/TC 37, Terminology and other language and content resources, Subcommittee SC 04, Language resource management. ISO 24617 consists of the following parts, under the general title Language resource management Semantic annotation framework:
16、 Part 1: Time and events (SemAF-Time, ISO-TimeML) Part 2: Dialogue acts (SemAF-DA) Part 4: Semantic roles (SemAF-SR) Part 5: Discourse structures (SemAF-DS) Part 6: Principles of semantic annotation (SemAF-Basics) Part 7: Spatial information (ISO-Space) Part 8: Semantic relations in discourse (SemAF
17、-DRel)iv ISO 2014 All rights reservedPD ISO/TS 24617-5:2014ISO/TS 24617-5:2014(E) Introduction Discourse structures play an essential role in the production and analysis of the syntactic, semantic, and pragmatic features of text, speech, and other types of discourse. This Technical Specification is
18、a basis both for the annotation, generation and translation (among other processes) of these types of discourses and of the syntactic, semantic, and pragmatic features derived from them. Note that discourse structures underlie not only verbal communication (whether spoken, written, or signed) but al
19、so non- verbal discourse (such as a silent video). The annotation scheme provided here specifies discourse structures that consist of segment structures and content structures. It also specifies the mappings between these two structures; the mappings are described by the annotations of discourse seg
20、ments in texts or some other modalities. In this context, on the one hand, segment structures are spatiotemporal relations that hold between surface segments (such as words, phrases, clauses, sentences, and video scenes) and, on the other hand, content structures are discourse relations that are est
21、ablished between semantic and pragmatic items. Both of these structures can be represented by means of labelled directed graphs or sometimes simply by trees, as standardized by LAF (ISO 24612:2012) and SynAF (ISO 24615:2010). This scheme also provides a common, language-neutral pivot for the interop
22、eration among diverse formats of discourse structures of various types of document, and can be applied to the generation of linguistic and non-linguistic expressions. For example, if the discourse structures of speech and other linguistic data contained in motion pictures are fitted to this scheme,
23、multilingual subtitles for these pictures can be generated at a reduced cost by means of a standardized tool for multilingual translation. By the same token, this scheme can facilitate interoperability among various discourse corpora and collaboration among researchers who use them. ISO 2014 All rig
24、hts reserved vPD ISO/TS 24617-5:2014PD ISO/TS 24617-5:2014Language resource management Semantic annotation framework (SemAF) Part 5: Discourse structure (SemAF-DS) 1 Scope A discourse is a process of communication. This Technical Specification addresses how a discourse is structured in terms of its
25、realization/presentation and content, and shows how its dual structure can be represented in a graph. The current specification focuses on the annotation of discourse structures in text only, but it can be extended to discourses in other modalities. 2 Normative references The following documents, in
26、 whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO/IEC 15938-5:2003/Amd.1:2004, I
27、nformation technology. Multimedia content description interface. Part 5: Multimedia description schemes AMENDMENT 1: Multimedia description schemes extensions (MPEG- 7 MDS AMD1) ISO 24612:2012, Language resource management Linguistic annotation framework (LAF) ISO 24615:2010, Language resource manag
28、ement Syntactic annotation framework (SynAF) ISO 24617-1:2012, Language resource management Semantic annotation framework Part 1: Time and events (SemAF-Time, ISO-TimeML) ISO 24617-2:2012, Language resource management Semantic annotation framework Part 2: Dialogue acts 3 T erms a nd definiti ons For
29、 the purposes of this document, the following terms and definitions apply. 3.1 circumstance entity which is an event (including dialogue act), state, process, relation, proposition, or set of these 3.2 class unary predicate, which is a set of entities 3.3 discourse process of communication, consisti
30、ng of one or more sentences or sentence fragments Note 1 to entry: From an abstract viewpoint, data (e.g. words, phrases, sentences, and paragraphs) representing a communication process is regarded as a discourse. A discourse can be encoded in various media such as text, hypertext, audio, video, and
31、 their possible combinations. TECHNICAL SPECIFICATION ISO/TS 24617-5:2014(E) ISO 2014 All rights reserved 1PD ISO/TS 24617-5:2014ISO/TS 24617-5:2014(E) 3.4 discourse relation semantic/pragmatic relation that holds among two or more circumstances Note 1 to entry: Some discourse relations, such as exa
32、mple and part, can also hold between objects. In this document, semantic/pragmatic relations (including discourse relations) are given in italics in the text and with a gray background in the Figures (e.g. agent, inference, and purpose). 3.5 discourse structure structure of discourse, comprising seg
33、ment structure, content structure, and possibly other types of structure 3.6 entity semantic/pragmatic entity referenced in discourse, including circumstances, and objects Note 1 to entry: An entity is represented by a node in a content structure. 3.7 object semantic entity other than circumstance N
34、ote 1 to entry: Objects include people, buildings, machines, ideas, and rules. 3.8 relational class class whose instances are circumstances equivalent to relations 3.9 segment word, phrase, clause, sentence, paragraph, section, chapter, or other partial realization of discourse Note 1 to entry: A sy
35、nonym is a discourse segment. A segment references a semantic and/or pragmatic entity, which can be a semantic/pragmatic relation. Intrasentential segments are syntactic constituents such as words, phrases, and clauses. Segments might or might not be continuous: this is discussed in the definition o
36、f connectives. 4 Overview A discourse structure consists of two types of structure: segment structure and content structure. A segment structure (extending intrasentential syntax) is a data structure that describes how a discourse has been organized from a formal syntactic perspective. It consists o
37、f a) a set of segments (some partial realizations of discourse), and b) the syntactic relations holding among them. A content structure (extending intrasentential semantics) is a data structure that describes from a logical point of view how a discourse has been organized. It consists of a) the set
38、of semantic and pragmatic components referred to by the segments of a segment structure (that is, by some segments of some discourse), and b) the logical relations established between these semantic representations. These two structures organize the whole structure of each discourse. Both types of s
39、tructure and content structures in particular, can be represented by means of a labelled directed graph. Various syntactic relations in a segment structure can, for instance, be captured by a tree (single-rooted graph). Discourse relations in a content structure can also be captured by a more genera
40、l graph: The nodes in the graph stand for semantic and pragmatic components and the edges formalize the relations holding among them. In one way, a segment structure is to a discourse (or part of 2 ISO 2014 All rights reservedPD ISO/TS 24617-5:2014ISO/TS 24617-5:2014(E) it) what a syntactic structur
41、e is to a sentence (or a sub-sentential component), and a content structure is to a discourse (or part of it) what a semantic structure is to a sentence (or a sub-sentential component). Rhetorical Structure Theory (RST) 4assumes that discourse has a tree-like structure that can be regarded as an ama
42、lgamation of segment structures and content structures. Corpus annotation based on RST 2considers segment structures involving markables, their annotations and, implicitly, some sort of content structures derived from them. Other corpus annotation initiatives such as the Prague Dependency Treebank 3
43、and the Penn Discourse TreeBank 6follow essentially the same approach. By contrast Segmented Discourse Representation Theory (SDRT) 1explicitly discusses content structures called Segmented Discourse Representation Structures (SDRSs), and with less commitment to segment structures and the mapping th
44、ereof. By integrating these recent practices in fields such as formal linguistics, knowledge representation and corpus annotation, this Technical Specification provides an annotation scheme to partially specify the segment structures and the mapping from them to their corresponding content structure
45、s. For the sake of interoperability across different ISO standards such as LAF and SynAF, this annotation scheme has been made interoperable with practices concerning syntax and intrasentential semantics; this mapping from segment structures to content structures is therefore a straightforward exten
46、sion of the mapping from syntactic structures to semantic structures, as addressed in many corpora, including the Penn TreeBank (PTB) 7and PropBank 5 . As for sentences, parse trees describe their syntax, and logical forms represent their semantics. As for discourses, however, their syntax (i.e. the
47、ir formal organization) and semantics (i.e. their content and logical organization) have been discussed in a more intertwined manner. For instance, most of the literature such as Reference 4 has regarded discourse relations as carrying both semantic and pragmatic information. This is inconvenient wh
48、en one wants to focus on the semantic aspects of discourses, for instance, which can be the case when dealing with hypertexts, games and so on, which lack prefixed temporal order of presentation, and when discussing multiple (e.g. multilingual) presentations of the same semantic content. To distingu
49、ish the realization/presentation and the content of a discourse and to address the mapping between them, this Technical Specification defines segment structures, content structures, and annotations to segments (discourse units) as part of segment structures. Segment structures represent the way in which the discourse is arranged, and consist of segments (e.g. words, phrases, clauses, sentences, paragraphs, sections, and chapters) together with the syntagmatic organization relations holding among the
