Temporal Contexts for Discourse Representation: An Extension of the Conceptual Graph Approach (original) (raw)

Integration of spatial and temporal information produced by a natural language discourse

1991

In the general context of a man-machine dialogue system, the adequate representation of the different kinds of data given by the user is very important. We present in this paper a method for representing temporal and spatial pieces of knowledge in an integrated manner, based on previous works done on temporal zones. Firstly, we present the two levels of time and space seperately, though they work on the same principles. Then, we show how these notions interact with each other through the definition of an object-universe, a structure which bears the different states and events undergone by any object referred to in a NL discourse. Within this representation, we propose a mechanism to acquire knew pieces of information by comparing two complex space-time structures. This leads us to show that the two levels are complementary to compute a specific situation in the world. Finally, we briefly address the use that can be made of this model to the understanding of a series of utterance in the present tense (description of a situation) and to the representation of the notion of event.

Aspecto-Temporal Representation for Discourse Analysis: An Example of Formal Computation

2011

This paper studies aspecto-temporal representation and the temporal relations of discourse. We give a formal definition of different aspectual operators from the formal notions of states, events and process which are necessary for adequate analysis of aspects and tenses in natural languages. The aim of this work is not to present a deep comparison of the two models (SDRT and CAG) but to focus on the presentation of a cognitive and computational architecture of the CAG. Our study is specifically based on the computational and cognitive architecture with 7 levels of representations in the CAG in using Combinatory Logic. This architecture allows relating by formal calculus abstract semantic representations and linguistic observables. We focus on temporal relations of discourse and the insertion of a predicative relation in different temporal frameworks.

Algorithms for analysing the temporal structure of discourse

Proceedings of the seventh conference on European chapter of the Association for Computational Linguistics -, 1995

We describe a method for analysing the temporal structure of a discourse which takes into account the effects of tense, aspect, temporal adverbials and rhetorical structure and which minimises unnecessary ambiguity in the temporal structure• It is part of a discourse grammar implemented in Carpenter's ALE formalism. The method for building up the temporal structure of the discourse combines constraints and preferences: we use constraints to reduce the number of possible structures, exploiting the HPSG type hierarchy and unification for this purpose; and we apply preferences to choose between the remaining options using a temporal centering mechanism• We end by recommending that an underspecified representation of the structure using these techniques be used to avoid generating the temporal/rhetorical structure until higher-level information can be used to disambiguate. the temporal component were to yield a detailed representation of the temporal structure of the discourse, taking into account the effect of tense, aspect and temporal expressions while at the same time minimising unnecessary ambiguity in the temporal structure. The method combines a constraint-based approach with an approach based on preferences: we exploit the HPSG type hierarchy and unification to arrive at a temporal structure using constraints placed on that structure by tense, aspect, rhetorical structure and temporal expressions, and we use the temporal centering preferences described by (Kameyama et al., 1993; Poesio, 1994) to rate the possibilities for temporal structure and choose' the best among them. The starting point for this work was Scha and Polanyi's discourse grammar (Scha Polanyi 1988; Priist et al 1994). For the implementation we extended the HPSG grammar (Pollard and Sag, 1994) which Gerald Penn and Bob Carpenter first encoded in ALE (Carpenter, 1993). This paper will focus on our temporal processing algorithm, and in particular on our analysis of narrative progression, rhetorical structure, perfects and temporal expressions•

Temporal Structure of Discourse

1992

In this paper discourse segments are defined and a method for discourse segmentation primarily based on abduction of temporal relations between segments is proposed. This method is precise and computationally feasible and is supported by previous work in the area of temporal anaphora resolution. I I)efinition of the rhetorical relation motivation [15]. ACTES DE COLING-92, NANTES, 23-28 hO'dT 1992 3 3 1 PROC. OF COLING-92, NANTES, AUO. 23-28, 1992

On representing the temporal structure of a natural language text

Proceedings of the 14th conference on Computational linguistics -, 1992

A proposal to deal with tenses in the framework of Discourse Representation Theory is presented, ms it has been implemented for a fragment at the IMS for the project LILOG. It is based on the theory of tenses of H. Kamp and Ch. Rohrer. The system uses tile tense and aspect information, the information about the temporal discourse structure of tile preceding text stored in a specific list of possible reference times, and background knowledge. These types of information interact in order to choose a suited temporal anchor for the event of a new sentence. With respect to extended texts, choosing the right reference time for a new event is a problem which has been largely neglected in the literature.

Modelling Structures for Situated Discourse

Dialogue & Discourse, 2020

This paper describes a corpus of situated multiparty chats developed for the STAC project (Strategic Conversation, ERC grant n. 269427). and annotated for discourse structure in the style of Segmented Discourse Representation Theory (SDRT; Asher & Lascarides,2003). The STAC corpus is not only a rich source of data on strategic conversation, but also the first corpus that we are aware of that provides discourse structures for multiparty dialogues situated within a virtual environment. The corpus was annotated in two stages: we initially annotated the chat moves only, but later decided to annotate interactions between the chat moves and non-linguistic events from the virtual environment. This two-step procedure has allowed us quantify various ways in which adding information from the nonlinguistic context affects dialogue structure. In this paper, we look at how annotations based only on linguistic information were preserved once the nonlinguistic context was factored in. We exp...

Representing Discourse in Context

Handbook of Logic and Language, 1997

This article gives a survey of Discourse Representation Theory (DRT), including recent developments, and with an emphasis on logical issues. Discourse representation structures are de ned, and various prespectives on their static and dynamic meaning are discussed. This discussion leads to the study of the process of merging representation structures, a process which can be viewed as a strategy for m e m o ry management. Next, a toy example fragment of English is presented, with a compositional DRT semantics. The nal sections are devoted to the treatment of quanti cation and of tense and aspect.

Representing events and discourse

2006

In [HKL00] (henceforth HKL), Hamm, Kamp and van Lambalgen declare “there is no opposition between formal and cognitive semantics,” notwithstanding the realist/mentalist divide. That divide separates two sides Jackendoff has (in [Jac96], following Chomsky) labeled E(xternalized)-semantics, relating language to a reality independent of speakers, and I(nternalized)-semantics, revolving around mental representations and thought. Although formal semanticists have (following David Lewis) traditionally leaned towards E-semantics, it is reasonable to apply formal methods also to I-semantics. This point is made clear in HKL via two computational approaches to natural language semantics, Discourse Representation Theory (DRT, [KR93]) and the Event Calculus (EC) presented in [LH05]. In this short note, I wish to raise certain questions about EC that can be traced to the applicability of formal methods to E-semantics and I-semantics alike. These opposing orientations suggest different notions of...

Prétexte: A Generator for the Expression of Temporal Information

1993

In this paper we present a method for generating French texts conveying temporal information. This method integrates the Discourse Representation Theory (DRT) and the Systemic Grammar Theory. First, we show how the DRT is used to represent temporal information. We then show how this formalism is used to represent the temporal localization expressed by temporal adverbial phrases. Finally, we give a description of how this representation of adverbial phrases can be translated into a syntactic form, using Systemic Grammar Theory. Prétexte, our implementation of this method, is able to generate a great variety of temporal adverbial phrases.