Aravind Joshi. How much context- sensitivity is required to provide reasonable structural descriptions: tree adjoining granunars. In D. Dowty, L. Kartunnen, and A. Zwick-y, editors, Natural Language Processing: Psycholinguisac. Computational and Theoretical Perspectives, Cambridge' Univea'sity Press.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....are not all of those posited by GB. Thus, the others must be enforced using a different mechanism. Unfommately, the unbounded size of the uee created with licensing makes any such mechanism computationally abhorrent. In order to remedy this, I make use of the Tree Adjoining Grammar (TAG) framework [Joshi, 1985] o limit the working space of the parser. As. the parser proc4is, its working structure is bounded in size. If this bouts] is exceeded, we reduce this structure by one of the operations provided by the TAG formalism, eithe substitution or adjundon. This results in two structures, each of which ....

Aravind Joshi. How much context- sensitivity is required to provide reasonable structural descriptions: tree adjoining granunars. In D. Dowty, L. Kartunnen, and A. Zwick-y, editors, Natural Language Processing: Psycholinguisac. Computational and Theoretical Perspectives, Cambridge' Univea'sity Press.

....with contexts shuffled on trajectories. The approach is very flexible, able to model various aspects from linguistics. TUCS Research Group Mathematical Structures of Computer Science 1 Introduction Mildly context sensitive families of languages were considered in connection with linguistics, see [7] and [8] The idea is to have a family of languages that contains the most significant languages that appear in the study of natural languages, and also, languages having good computational properties, i.e. the membership problem for languages in this family should be solvable in deterministic ....

Joshi, A.K.; "How much context-sensitivity is required to provide reasonable structural descriptions? Tree adjoining grammars", in Natural Language Processing: Psycholinguistic, Computational, and Theoretic Perspectives, D.R. Dowty et al., eds., Cambridge University Press, New York, 1985, 206 - 250.

....feature structures can in theory lead to np complete complexity: printing the first valid parse may require exponential time. Such complex interactions are however rare in natural language. There is growing agreement among researchers about the mild context sensitiveness of natural language [Joshi, 1985; Vijay Shanker and Weir, 1994] This means that NL grammars deviate only minimally in complexity from the context free class. Thus, although NL grammars written in a unification formalism may appear superficially to be highly context sensitive, most of the interactions between features tend to ....

A. K. Joshi. How much context-sensitivity is required to provide reasonable structural descriptions: Tree adjoining grammars. In D. Dowty, L. Karttunen, and A. Zwicky, editors, Natural Language Parsing: Psycholinguistic, Computational and Theoretical Perspectives, pages 206--250. Cambridge University Press, New York, 1985.

....generative mechanisms aiming to model (specific constructions in) natural languages should be powerful enough to cover the linguistic reality but not too powerful, producing languages which have no connection with the natural ones. Specifically, the notion of mildly context sensitive languages, [10], has become popular. After long debates started in sixties, 2] 3] the linguists seem to finally agree that the natural languages are not context free, several languages (Bambara dialect, 4] Swiss German, 27] etc) contain convincing non context free features and probably most natural ....

A. K. Joshi, How much context-sensitivity is required to provide reasonable structural descriptions ? Tree adjoining grammars, in Natural Language Processing: Psycholinguistic, Computational, and Theoretic Perspectives (D. R. Dowty et al, eds.), Cambridge Univ. Press, New York, 1985, 206 -- 250.

....to syntax from the field of computational linguistics that provides an interesting perspective from which to view results in the production literature. This approach is known as tree adjoining grammars (TAGs) and is associated with Aravind Joshi and his colleagues and students (Frank, 1992; Joshi, 1985; Joshi, Levy, Takahashi, 1975; Kroch Joshi, 1985) The important fundamental feature of this approach is that it assumes the existence of primitive, basic syntactic trees, which are combined in various constrained ways. This description of TAG will highlight the characteristics of elementary ....

....that provides an interesting perspective from which to view results in the production literature. This approach is known as tree adjoining grammars (TAGs) and is associated with Aravind Joshi and his colleagues and students (Frank, 1992; Joshi, 1985; Joshi, Levy, Takahashi, 1975; Kroch Joshi, 1985). The important fundamental feature of this approach is that it assumes the existence of primitive, basic syntactic trees, which are combined in various constrained ways. This description of TAG will highlight the characteristics of elementary trees, the ways they may be combined, and the ....

Joshi, A.K. (1985). How much context-sensitivity is required to provide reasonable structural descriptions: tree adjoining grammars. In D. Dowty, L. Kartunnen, and A. Zwicky (Eds.), Natural Language Parsing: Psychological, Computational, and Theoretical Perspectives. Cambridge: Cambridge University Press.

....feature structures can in theory lead to np complete complexity: printing the first valid parse may require exponential time. Such complex interactions are however rare in natural language. There is growing agreement among researchers about the mild context sensitiveness of natural language [Joshi, 1985, Vijay Shanker and Weir, 1994] This means that NL grammars deviate only minimally in complexity from the contextfree class. Thus, although NL grammars written in a unification formalism may appear superficially to be highly context sensitive, most of the interactions between features tend to be ....

A. K. Joshi. How much context-sensitivity is required to provide reasonable structural descriptions: Tree adjoining grammars. In D. Dowty, L. Karttunen, and A. Zwicky, editors, Natural Language Parsing: Psycholinguistic, Computational and Theoretical Perspectives, pages 206--250. Cambridge University Press, New York, 1985.

....certain constructions such as crossed serial dependencies in Dutch. Consequently, many computational linguists have turned to mildly context sensitive grammars which are computationally tractable (i.e. polynomially parsable) but also able to generate some languages outside of the class of CFLs (Joshi 1985). Combinatory Categorial Grammars (CCGs, Steedman 1990b,1991a,1991c,1991b) which are an extension of pure Categorial Grammars (Ajdukiewicz 1935, Bar Hillel 1953) are lexicalized grammars that generate such mildly context sensitive languages. 1 A lexicalized grammar is one in which each lexical ....

....that is adaptable to this property. For example, there are a variety of other categorial formalisms that produce similar types of non traditional syntactic constituents (Moortgat 1989, Oehrle 1988, Dowty 1988) Moreover, there are non categorial formalisms, such as Tree Adjoining Grammar (TAG) (Joshi 1985) and Linear Indexed Grammar (LIG) that have been shown to possess generative power that is weakly equivalent to CCG (Weir 1988) where weak equivalence is defined as follows. Definition 5.1 Two grammars, G and G 0 are weakly equivalent if L(G) the set of strings generated by G, is identical to ....

Joshi, A. K. (1985). How much context-sensitivity is required to provide reasonable structural descriptions: Tree-adjoining grammars. In Dowty, D., Karttunen, L., and Zwicky, A., editors, Natural Language Parsing: Psycholinguistic, Computational and Theoretical Perspectives, pages 206--350. Cambridge University Press, New York.

....I owe much to Ellen Prince who shaped my approach to linguistics starting from my first year at Penn. Her insightful comments stimulated my research and my interest in language. I greatly appreciate the constructive criticism, comments, and suggestions provided by my other committee members: Aravind Joshi, Mark Johnson, and Mitch Marcus. I would also like to thank Annette Herskovits for introducing me to computational linguistics and for her friendship over the years. My work was greatly influenced by Owen Rambow and Umit Turan; I have enjoyed their friendship as well as stimulating discussions ....

Aravind Joshi. 1985. How much context-sensitivity is required to provide reasonable structural descriptions: Tree-adjoing grammars. In D. Dowty, L. Karttunen, and A. Zwicky, editors, Natural Language Parsing: Psycholinguistic, Computational and Theoretical Perspectives, pages 206--350. Cambridge U Press, New York.

....of regularities. 3 An Extension of TAGs for Incremental and Parallel Generation The discussion of design principles results in the need for a representation formalism that is not only adequate for the description of syntactic structures as is Tree Adjoining Grammar (cf. Joshi 83] Joshi 85] but additionally fulfills the demands of incremental natural language generation as described above. The formalism has to support the stepwise expansion of structures, the distribution of structures among objects of a parallel system, lexical guidance, and the separate description of ....

A. K. Joshi. How much Context-Sensitivity is required to provide Reasonable Structural Descriptions: TAGs. In: D. Dowty, L. Karttunen, and A. Zwicky (eds.), Natural Language Processing: Psychological, Computational and Theoretical Perspectives. New York: Cambridge University Press, 1985.

....grammatical and ungrammatical. In this paper, we continue our exploration, now of some year s duration, of a particular compositional theory of phrase structure , one related to Chomsky s recent work as he himself notes, but making use of different operations from those he employs (cf. Kroch and Joshi 1985, 1987, Kroch and Santorini 1991, Frank 1992, Frank and Kroch 1994, inter alia) In particular, we exploit the combinatorial operations of Tree Adjoining Grammar (TAG) namely adjoining and substitution. This system avoids the unnecessary distinction between Chomsky s two modes of phrase ....

....the shortest move and extension requirements so much as possible. In the next section, we will consider a composition system of phrase structure which does just this. 3 An Alternative Theory of Generalized Transformations: Tree Adjoining Grammar The TAG formalism (Joshi, Levy and Takahashi 1975, Joshi 1985, Kroch and Joshi 1985) was developed some twenty years ago as a mathematically restrictive formulation of phrase structure composition, inspired in part by Chomsky s earlier work on generalized transformations. As such, it provides an alternative to Chomsky s (1992) proposals. In TAG, structural ....

[Article contains additional citation context not shown here]

Joshi, Aravind K. 1985. How much context-sensitivity is required to provide reasonable structural descriptions: tree adjoining grammars. In David Dowty, Lauri Kartunnen, and Arnold Zwicky (Eds.), Natural Language Parsing: Psychological, Computational and Theoretical Perspectives.

....is needed to decide whether this linguistic motivation warrants the move to a more powerful formalism. Although VAR CCGs have a greater weak generative capacity than the class including TAGs, HGs, CCGs, and LIGs, we conjecture that it is still a mildly context sensitive grammar as defined by Joshi (1985). The language discussed above is a mildly contextsensitive language since it observes the constant growth and semilinearity properties. It is an open question whether VAR CCGs can generate languages which are beyond mildly context sensitive. Note that MC TAGs, which are a more powerful extension ....

Joshi, A.K., 1985. How much context-sensitivity is required to provide reasonable structural descriptions: Tree adjoining grammars. in D. Dowty and L. Karttunen and A. Zwicky, editors, Natural Language Parsing: Psycholinguistic, Computational and Theoretical Perspectives, Cambridge University Press.

....and therefore will not produce recursive structures when they appear as the complements of verbs. This difference has no obvious significance for a transformational analysis; but, as we will see, if we state our grammatical analysis of these constructions in the formalism of Tree Adjoining Grammar (Joshi 1985) and use, with some refinements, the analysis of wh movement in Kroch (1989b) we can derive the differences between nominalizations and gerunds from differences in the formal operations by which they are incorporated into a syntactic derivation: gerunds through simple TAG adjoining, and ....

....as (i) provide strong support for such a conclusion. i) Alice denied that I seemed to anyone to be drunk. Here, the NPI anyone will need to be licensed locally within the seem auxiliary tree which gives rise to the raising structure following the analysis of raising in Frank (1992) and Kroch and Joshi (1985). In order for the Polarity feature to percolate correctly into this structure, it must be present on the IP projection, in Frank s analysis on the top feature structure of the I 0 node of the be drunk tree. A further discussion of these cases would take us quite far afield, however, and we ....

Joshi, Aravind K. 1985. How much context-sensitivity is required to provide reasonable structural descriptions: tree adjoining grammars. In D. Dowty, L. Kartunnen, and A. Zwicky (Eds.), Natural Language Parsing: Psycholinguistic, Computational and Theoretical Perspectives. Cambridge University Press.

....and therefore will not produce recursive structures when they appear as the complements of verbs. This difference has no obvious significance for a transformational analysis; but, as we will see, if we state our grammatical analysis of these constructions in the formalism of Tree Adjoining Grammar (Joshi 1985) and use, with some refinements, the analysis of wh movement in Kroch (1989b) we can derive the differences between nominalizations and gerunds from differences in the formal operations by which they are incorporated into a syntactic derivation: gerunds through simple TAG adjoining, and ....

....as (i) provide strong support for such a conclusion. i) Alice denied that I seemed to anyone to be drunk. Here, the NPI anyone will need to be licensed locally within the seem auxiliary tree which gives rise to the raising structure following the analysis of raising in Frank (1992) and Kroch and Joshi (1985). In order for the Polarity feature to percolate correctly into this structure, it must be present on the IP projection, in Frank s analysis on the top feature structure of the I 0 node of the be drunk tree. A further discussion of these cases would take us quite far afield, however, and we ....

Joshi, Aravind K. 1985. How much context-sensitivity is required to provide reasonable structural descriptions: tree adjoining grammars. In D. Dowty, L. Kartunnen, and A. Zwicky (Eds.), Natural Language Processing: Psycholinguistic, Computational and Theoretical Perspectives . Cambridge University Press.

....nonterminal X (see Figure 2) The operation adjunction together with the depth of the concerned trees which forms the context for the combination makes TAG a mildly context sensitive formalism. These characteristics make it an adequate candidate for the description of natural language 12 (cf. Joshi 85a] Weir 88] The relevance of TAG to natural language processing results from the fact that its extended domain of locality allows for the specification of various related units within one elementary structure. For example, a predicate and all its arguments can be defined within a single ....

A.K. Joshi. How much Context-Sensitivity is Required to Provide Reasonable Structural Descriptions: Tree Adjoining Grammars. In: D. Dowty, L. Karttunen, and A. Zwicky (eds.), Natural Language Processing: Psycholinguistic, Computational and Theoretical Perspectives, pp. 206--250. Cambridge: Cambridge University Press, 1985.

....contexts shuffled on trajectories. The approach is very flexible, able to model various aspects from linguistics. TUCS Research Group Mathematical Structures of Computer Science 1 Introduction Mildly context sensitive families of languages were considered in connection with linguistics, see [7] and [8] The idea is to have a family of languages that contains the most significant languages that appear in the study of natural languages, and also, languages having good computational properties, i.e. the membership problem for languages in this family should be solvable in deterministic ....

Joshi, A.K.; "How much context-sensitivity is required to provide reasonable structural descriptions? Tree adjoining grammars", in Natural Language Processing: Psycholinguistic, Computational, and Theoretic Perspectives, D.R. Dowty et al., eds., Cambridge University Press, New York, 1985, 206 - 250.

No context found.

Joshi, A.K.,"How much context-sensitivity is required to provide adequate structural descriptions ?", in Natural language processing: Psycholinulstic, Theoretical, and Computational Perseptives, (edso Dowry, D., KarllUnCh, L., and Zwicky, Ao), Cambridge University Press, (to appear).

No context found.

A.K. Joshi. How much context-sensitivity is required to provide reasonable structural descriptions: tree adjoining grammars. In D. Dowty, L. Karttunen, and A. Zwicky, editors, Natural Language Parsing: Psycholinguistic, Computational and Theoretical Perspectives, pages 206-- 250, Cambridge University Press, New York, 1985.

No context found.

Aravind K. Joshi. How much context-sensitivity is required to provide reasonable structural descriptions: Tree adjoining grammars. In D. Dowty and Lauri Karttunen, editors, Natural Language Processing: Psycholinguistic, Computational, and Theoretical Perspectives. Cambridge University Press, New York, 1983.

Online articles have much greater impact   More about CiteSeer.IST   Add search form to your site   Submit documents   Feedback  

CiteSeer.IST - Copyright Penn State and NEC