Generalised phrase structure grammar
Encyclopedia
Generalised phrase structure grammar (GPSG) is a framework for describing the syntax
and semantics
of natural language
s. It is a type of phrase structure grammar
, as opposed to a dependency grammar
. GPSG was initially developed in the late 1970s by Gerald Gazdar
. Other contributors include Ewan Klein, Ivan Sag
, and Geoffrey Pullum
. Their book Generalized Phrase Structure Grammar, published in 1985, is the main monograph on GPSG, especially as it applies to English syntax.
One of the chief goals of GPSG is to show that the syntax of natural languages can be described by context-free grammar
s (written as ID/LP grammar
s), with some suitable conventions intended to make writing such grammars easier for syntacticians. Among these conventions are a sophisticated feature structure
system and so-called "meta-rules", which are rules generating the productions of a context-free grammar. GPSG further augments syntactic descriptions with semantic annotations that can be used to compute the compositional meaning of a sentence from its syntactic derivation tree. However, it has been argued (for example by Robert Berwick) that these extensions require parsing algorithms of a higher order of computational complexity
than those used for basic CFGs.
Gerald Gazdar, and many other syntacticians, have since argued that natural languages cannot in fact be adequately described by CFGs http://www.informatics.susx.ac.uk/research/nlp/gazdar/briscoe/gpsg.html.
GPSG is in part a reaction against transformational theories of syntax
. In fact, the notational extensions to context-free grammars developed in GPSG are claimed to make transformations redundant. Most of the syntactic innovations of GPSG were subsequently incorporated into head-driven phrase structure grammar
.
Syntax
In linguistics, syntax is the study of the principles and rules for constructing phrases and sentences in natural languages....
and semantics
Semantics
Semantics is the study of meaning. It focuses on the relation between signifiers, such as words, phrases, signs and symbols, and what they stand for, their denotata....
of natural language
Natural language
In the philosophy of language, a natural language is any language which arises in an unpremeditated fashion as the result of the innate facility for language possessed by the human intellect. A natural language is typically used for communication, and may be spoken, signed, or written...
s. It is a type of phrase structure grammar
Phrase structure grammar
The term phrase structure grammar was originally introduced by Noam Chomsky as the term for grammars as defined by phrase structure rules, i.e. rewrite rules of the type studied previously by Emil Post and Axel Thue...
, as opposed to a dependency grammar
Dependency grammar
Dependency grammar is a class of modern syntactic theories that are all based on the dependency relation and that can be traced back primarily to the work of Lucien Tesnière. Dependency grammars are distinct from phrase structure grammars , since they lack phrasal nodes. Structure is determined by...
. GPSG was initially developed in the late 1970s by Gerald Gazdar
Gerald Gazdar
Gerald James Michael Gazdar is a linguist and computer scientist.He was educated at Bradfield College and subsequently graduated from the University of East Anglia with a BA in 1970, and from the University of Reading where he completed his master's degree in 1972 and his PhD in 1976...
. Other contributors include Ewan Klein, Ivan Sag
Ivan Sag
Ivan Sag is an American linguist and cognitive scientist. He is the Sadie Dernham Patek Professor in Humanities, Professor of Linguistics, and Director of the Symbolic Systems Program at Stanford University...
, and Geoffrey Pullum
Geoffrey Pullum
Geoffrey Keith "Geoff" Pullum is a British-American linguist specialising in the study of English. , he is Professor of General Linguistics at the University of Edinburgh....
. Their book Generalized Phrase Structure Grammar, published in 1985, is the main monograph on GPSG, especially as it applies to English syntax.
One of the chief goals of GPSG is to show that the syntax of natural languages can be described by context-free grammar
Context-free grammar
In formal language theory, a context-free grammar is a formal grammar in which every production rule is of the formwhere V is a single nonterminal symbol, and w is a string of terminals and/or nonterminals ....
s (written as ID/LP grammar
ID/LP grammar
An ID/LP grammar is a formal grammar that distinguishes immediate dominance constraints from linear precedence constraints. Whereas traditional phrase structure rules incorporate dominance and precedence into a single rule, ID/LP maintains separate rule sets which need not be processed...
s), with some suitable conventions intended to make writing such grammars easier for syntacticians. Among these conventions are a sophisticated feature structure
Feature structure
In phrase structure grammars, such as generalised phrase structure grammar, head-driven phrase structure grammar and lexical functional grammar, a feature structure is essentially a set of attribute-value pairs. For example the attribute named number might have the value singular. The value of an...
system and so-called "meta-rules", which are rules generating the productions of a context-free grammar. GPSG further augments syntactic descriptions with semantic annotations that can be used to compute the compositional meaning of a sentence from its syntactic derivation tree. However, it has been argued (for example by Robert Berwick) that these extensions require parsing algorithms of a higher order of computational complexity
Computational Complexity
Computational Complexity may refer to:*Computational complexity theory*Computational Complexity...
than those used for basic CFGs.
Gerald Gazdar, and many other syntacticians, have since argued that natural languages cannot in fact be adequately described by CFGs http://www.informatics.susx.ac.uk/research/nlp/gazdar/briscoe/gpsg.html.
GPSG is in part a reaction against transformational theories of syntax
Transformational grammar
In linguistics, a transformational grammar or transformational-generative grammar is a generative grammar, especially of a natural language, that has been developed in the Chomskyan tradition of phrase structure grammars...
. In fact, the notational extensions to context-free grammars developed in GPSG are claimed to make transformations redundant. Most of the syntactic innovations of GPSG were subsequently incorporated into head-driven phrase structure grammar
Head-driven phrase structure grammar
Head-driven phrase structure grammar is a highly lexicalized, non-derivational generative grammar theory developed by Carl Pollard and Ivan Sag. It is the immediate successor to generalized phrase structure grammar. HPSG draws from other fields such as computer science and uses Ferdinand de...
.
External links
- Gerald Gazdar's homepage, containing links to publications on GPSG.