Presuppositions in Context: Constructing Bridges

About the book: The First International and Interdisciplinary Conference on Modelling and Using Context, Rio de Janeiro, January 1997, gave rise to the present book, which contains a selection of the papers presented there, thoroughly refereed and revised. The treatment of contexts as bona fide objects of logical formalisation has gained wide acceptance, following the seminal impetus given by McCarthy in his Turing Award address. The field of natural language offers a particularly rich variety of examples and challenges to researchers concerned with the formal modelling of context, and several chapters in the volume deal with contextualisation in the setting of natural language. Others adopt a purely formal-logical viewpoint, seeking to develop general models of even wider applicability. The 12 chapters are organised in three groups: formalisation of contextual information in natural language understanding and generation, the application of context in mechanised reasoning domains, and novel non-classical logics for contextual application

Information flow and gaps

In this paper we provide an outline of a model for the flow information in conversations. We explain the model by means of a metaphor. We propose that certain natural language phrases (i.e., anaphoric expressions and questions) are used to express gaps. These gaps are what gives rise to information flow in conversations. After dealing with a simple conversational exchange in terms of this approach, we proceed to deal with different forms of indirect information transfer in conversations as they are manifested by bridging anaphors and indirect answers. At that point, we will leave the metaphorical presentation behind us and examine some of the details of our logic-based model itself. For the full details of the model we refer to Piwek (1998)

Situated action and commitment in dialogue

In this paper, a formal model of communication in dialogues is described. Recently, a shift seems to have taken place from the traditional perception of the computer as a mere tool for carrying out a task towards a view of the computer as an assistant with which one or more users work together - i.e., cooperate - on a task. Now, cooperation is rooted in coordination of actions, which in turn can be achieved through communication. The model for cooperative behaviour in dialogues that we propose is based on observational studies into human-human communication carried out at IPO and findings from Discourse Analysis and Conversation Analysis. Our main concern will be to explain the role of the basic constituents of conversation that are known as adjacency pairs. Central in our model are rules that describe how the commitments of the dialogue partners are updated during the course of a dialogue and how they constrain the possible moves of the dialogue participants. We take communication to be part of the overall activity in which the interlocutors are engaged. Such a model is needed if we want to account for the fact that information is often exchanged in dialogues in a sequence of alternating (combinations of) modalities (linguistic means, object manipulations and/or gestures). The model was used for the behaviour rules of an artificial assistant that is implemented as part of the DenK (Dialogue Modelling and Knowledge Acquisition) project

Situated action and commitment in dialogue

In this paper, a formal model of communication in dialogues is described. Recently, a shift seems to have taken place from the traditional perception of the computer as a mere tool for carrying out a task towards a view of the computer as an assistant with which one or more users work together - i.e., cooperate - on a task. Now, cooperation is rooted in coordination of actions, which in turn can be achieved through communication. The model for cooperative behaviour in dialogues that we propose is based on observational studies into human-human communication carried out at IPO and findings from Discourse Analysis and Conversation Analysis. Our main concern will be to explain the role of the basic constituents of conversation that are known as adjacency pairs. Central in our model are rules that describe how the commitments of the dialogue partners are updated during the course of a dialogue and how they constrain the possible moves of the dialogue participants. We take communication to be part of the overall activity in which the interlocutors are engaged. Such a model is needed if we want to account for the fact that information is often exchanged in dialogues in a sequence of alternating (combinations of) modalities (linguistic means, object manipulations and/or gestures). The model was used for the behaviour rules of an artificial assistant that is implemented as part of the DenK (Dialogue Modelling and Knowledge Acquisition) project

Information flow and gaps

In this paper we provide an outline of a model for the flow information in conversations. We explain the model by means of a metaphor. We propose that certain natural language phrases (i.e., anaphoric expressions and questions) are used to express gaps. These gaps are what gives rise to information flow in conversations. After dealing with a simple conversational exchange in terms of this approach, we proceed to deal with different forms of indirect information transfer in conversations as they are manifested by bridging anaphors and indirect answers. At that point, we will leave the metaphorical presentation behind us and examine some of the details of our logic-based model itself. For the full details of the model we refer to Piwek (1998)

Dutch and English demonstratives : a comparison

In this paper we examine to what extent the use of demonstratives in Dutch differs from that in English. We look into the distribution of distal and proximate demonstratives (e.g. that vs. this, and in Dutch dat/die vs. dit/deze). In the literature the distribution of proximate and distal demonstratives in English and Dutch was found to be correlated with the so-called accessibility of the intended refer ent. Accessibility stands for the relative ease with which the addressee can identify the referent, and can be increased by factors like topic-hood and salience. Dutch proximate demonstratives are preferred for referring to entities which are relatively hard to access. English language users, according to some of the literature, follow the opposite strategy: they use proximate demonstratives to retrieve referents that are relatively easy to access. In both languages the use of distal demonstratives is equally distributed over more and less accessible referents. In order to check these findings we collected new data in an experimental setting. The new data led us towards a more finegrained notion of accessibility (in particular for physical domains), which takes temporal factors into account