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Rhetorical structure theory (RST) is a theory of text organization that describes relations that hold between parts of text. It was originally developed by William Mann, Sandra Thompson, Christian M. I. M. Matthiessen and others at the University of Southern California's Information Sciences Institute (ISI) and defined in a 1988 paper. [1] [2] [3] The theory was developed as part of studies of computer-based text generation. Natural language researchers later began using RST in text summarization and other applications. It explains coherence by postulating a hierarchical, connected structure of texts. [3] In 2000, Daniel Marcu, also of ISI, demonstrated that practical discourse parsing and text summarization also could be achieved using RST. [4] [5] [6]
Rhetorical relations or coherence relations or discourse relations are paratactic (coordinate) or hypotactic (subordinate) relations that hold across two or more text spans. [7] It is widely accepted that notion of coherence is through text relations like this. RST using rhetorical relations provide a systematic way for an analyst to analyse the text. An analysis is usually built by reading the text and constructing a tree using the relations. The following example is a title and summary, appearing at the top of an article in Scientific American magazine (Ramachandran and Anstis, 1986). The original text, broken into numbered units, is: [3]
In the figure, numbers 1,2,3,4 show the corresponding units as explained above. The fourth unit and the third unit form a relation "Means". The third unit is the essential part of this relation, so it is called the nucleus of the relation and fourth unit is called the satellite of the relation. Similarly second unit to third and fourth unit is forming relation "Condition". All units are also spans and spans may be composed of more than one unit.
RST establishes two different types of units. Nuclei are considered as the most important parts of text whereas satellites contribute to the nuclei and are secondary. Nucleus contains basic information and satellite contains additional information about nucleus. The satellite is often incomprehensible without nucleus, whereas a text where a satellites have been deleted can be understood to a certain extent.
RST relations are applied recursively in a text, until all units in that text are constituents in an RST relation. The result of such analyses is that RST structure are typically represented as trees, with one top level relation that encompasses other relations at lower levels.
Computer scientists Ana Cristina Bicharra Garcia and Clarisse Sieckenius de Souz have used RST as the basis of a design rationale system called ADD+. [10] [11] In ADD+, RST is used as the basis for the rhetorical organization of a knowledge base, in a way comparable to other knowledge representation systems such as issue-based information system (IBIS). [11] Similarly, RST has been used in representation schemes for argumentation. [12] [13] [14]
Natural language processing (NLP) is a subfield of computer science and especially artificial intelligence. It is primarily concerned with providing computers with the ability to process data encoded in natural language and is thus closely related to information retrieval, knowledge representation and computational linguistics, a subfield of linguistics. Typically data is collected in text corpora, using either rule-based, statistical or neural-based approaches in machine learning and deep learning.
Rhetoric is the art of persuasion. It is one of the three ancient arts of discourse (trivium) along with grammar and logic/dialectic. As an academic discipline within the humanities, rhetoric aims to study the techniques that speakers or writers use to inform, persuade, and motivate their audiences. Rhetoric also provides heuristics for understanding, discovering, and developing arguments for particular situations.
A semantic network, or frame network is a knowledge base that represents semantic relations between concepts in a network. This is often used as a form of knowledge representation. It is a directed or undirected graph consisting of vertices, which represent concepts, and edges, which represent semantic relations between concepts, mapping or connecting semantic fields. A semantic network may be instantiated as, for example, a graph database or a concept map. Typical standardized semantic networks are expressed as semantic triples.
Discourse is a generalization of the notion of a conversation to any form of communication. Discourse is a major topic in social theory, with work spanning fields such as sociology, anthropology, continental philosophy, and discourse analysis. Following work by Michel Foucault, these fields view discourse as a system of thought, knowledge, or communication that constructs our world experience. Since control of discourse amounts to control of how the world is perceived, social theory often studies discourse as a window into power. Within theoretical linguistics, discourse is understood more narrowly as linguistic information exchange and was one of the major motivations for the framework of dynamic semantics. In these expressions, ' denotations are equated with their ability to update a discourse context.
Lexical functional grammar (LFG) is a constraint-based grammar framework in theoretical linguistics. It posits two separate levels of syntactic structure, a phrase structure grammar representation of word order and constituency, and a representation of grammatical functions such as subject and object, similar to dependency grammar. The development of the theory was initiated by Joan Bresnan and Ronald Kaplan in the 1970s, in reaction to the theory of transformational grammar which was current in the late 1970s. It mainly focuses on syntax, including its relation with morphology and semantics. There has been little LFG work on phonology.
Critical discourse analysis (CDA) uncovers the hidden meanings embedded in texts and conversations. It analyses the way the language used reinforces power relationships, social hierarchies, and ideologies.
Visual rhetoric is the art of effective communication through visual elements such as images, typography, and texts. Visual rhetoric encompasses the skill of visual literacy and the ability to analyze images for their form and meaning. Drawing on techniques from semiotics and rhetorical analysis, visual rhetoric expands on visual literacy as it examines the structure of an image with the focus on its persuasive effects on an audience.
Discourse analysis (DA), or discourse studies, is an approach to the analysis of written, spoken, or sign language, including any significant semiotic event.
In linguistics, focus is a grammatical category that conveys which part of the sentence contributes new, non-derivable, or contrastive information. In the English sentence "Mary only insulted BILL", focus is expressed prosodically by a pitch accent on "Bill" which identifies him as the only person whom Mary insulted. By contrast, in the sentence "Mary only INSULTED Bill", the verb "insult" is focused and thus expresses that Mary performed no other actions towards Bill. Focus is a cross-linguistic phenomenon and a major topic in linguistics. Research on focus spans numerous subfields including phonetics, syntax, semantics, pragmatics, and sociolinguistics.
Text linguistics is a branch of linguistics that deals with texts as communication systems. Its original aims lay in uncovering and describing text grammars. The application of text linguistics has, however, evolved from this approach to a point in which text is viewed in much broader terms that go beyond a mere extension of traditional grammar towards an entire text. Text linguistics takes into account the form of a text, but also its setting, i. e. the way in which it is situated in an interactional, communicative context. Both the author of a text as well as its addressee are taken into consideration in their respective roles in the specific communicative context. In general it is an application of discourse analysis at the much broader level of text, rather than just a sentence or word.
Systemic functional linguistics (SFL) is an approach to linguistics, among functional linguistics, that considers language as a social semiotic system.
Narrative paradigm is a communication theory conceptualized by 20th-century communication scholar Walter Fisher. The paradigm claims that all meaningful communication occurs via storytelling or reporting of events. Humans participate as storytellers and observers of narratives. This theory further claims that stories are more persuasive than arguments. Essentially the narrative paradigm helps us to explain how humans are able to understand complex information through narrative.
Frame semantics is a theory of linguistic meaning developed by Charles J. Fillmore that extends his earlier case grammar. It relates linguistic semantics to encyclopedic knowledge. The basic idea is that one cannot understand the meaning of a single word without access to all the essential knowledge that relates to that word. For example, one would not be able to understand the word "sell" without knowing anything about the situation of commercial transfer, which also involves, among other things, a seller, a buyer, goods, money, the relation between the money and the goods, the relations between the seller and the goods and the money, the relation between the buyer and the goods and the money and so on. Thus, a word activates, or evokes, a frame of semantic knowledge relating to the specific concept to which it refers.
Jerry R. Hobbs is an American researcher in the fields of computational linguistics, discourse analysis, and artificial intelligence.
In linguistics, a treebank is a parsed text corpus that annotates syntactic or semantic sentence structure. The construction of parsed corpora in the early 1990s revolutionized computational linguistics, which benefitted from large-scale empirical data.
Rhetoric of science is a body of scholarly literature exploring the notion that the practice of science is a rhetorical activity. It emerged after a number of similarly oriented topics of research and discussion during the late 20th century, including the sociology of scientific knowledge, history of science, and philosophy of science, but it is practiced most typically by rhetoricians in academic departments of English, speech, and communication.
RST may refer to:
The sequence between semantic related ordered words is classified as a lexical chain. A lexical chain is a sequence of related words in writing, spanning narrow or wide context window. A lexical chain is independent of the grammatical structure of the text and in effect it is a list of words that captures a portion of the cohesive structure of the text. A lexical chain can provide a context for the resolution of an ambiguous term and enable disambiguation of concepts that the term represents.
A discourse relation is a description of how two segments of discourse are logically and/or structurally connected to one another.
William C. "Bill" Mann was a computer scientist and computational linguist, the originator of rhetorical structure theory (RST) and a president of the Association for Computational Linguistics (1987–1988). He is especially well known for his work in text generation.