Abductive speech act recognition, corporate agents and the COSMA system

This chapter presents an overview of the DISCO project\u27s solutions to several problems in natural language pragmatics. Its central focus is on relating utterances to intentions through speech act recognition. Subproblems include the incorporation of linguistic cues into the speech act recognition process, precise and efficient multiagent belief attribution models (Corporate Agents), and speech act representation and processing using Corporate Agents. These ideas are being tested within the COSMA appointment scheduling system, one application of the DISCO natural language interface. Abductive speech act processing in this environment is not far from realizing its potential for fully bidirectional implementation

Corporate agents

The logic of belief and intention in situations with multiple agents is increasingly well understood, but current formal approaches appear to face problems in applications where the number of agents greatly exceeds two. We provide an informal development of Corporate Agents, an intensional approximation of individual and group states which treats groups symmetrically with autonomous agents. Corporate Charters, constraints derived from typical patterns of information flow, replace detailed reasoning about the propagation of attitudes in most contexts. The approximation to an ideal logical formulation is not tight, but the model appears to function well in information-poor environments and fails in ways related to characteristic human errors. It may therefore be particularly appropriate to application in the area of natural language discourse

Communicating with Multiple Agents

Previous dialogue systems have focussed on dia. logues betwe(:n two agents. Many ~q)plications, however, require conversations between several l)articipants. This paper extends speech act deftnitions to handle multi-agent conversations, based on a model of multi-agent belief attribution with some unique properties. Our approach has |,lie advantage of capturing a lnnnlmr of interesting phenomena in a straightforward way

Funser: a Functional Server for Textual Information Retrieval

The paper describes a data-intensive application written in a lazy functional language: a server for textual information retrieval. The design illustrates the importance of interoperability, the capability of interacting with code written in other programming languages. Lazy functional programming is shown to be a powerful and elegant means of accomplishing several desirable concrete goals: delivering initial results promptly, using space economically, and avoiding unnecessary I/O. Performance results, however, are mixed. 1 Introduction Is it possible to write a "real" application in a pure functional language? This question has been asked many times, at conferences, on Internet newsgroups, and in papers, and perhaps the answer is beginning to be yes. This paper describes work that attempts to answer this question in the context of full-text information retrieval; for this kind of "real" application, we have found the answer to be, for now, maybe. The researchers at the Center for Inf..

Using a Lazy Functional Language for Textual Information Retrieval

This paper describes a new implementation technique for index-assisted searching in a textual database: the use of a lazy functional programming language to describe high-level search strategies, combined with low-level implementation languages (such as C) for primitive index and text access. Our implementation, in the concrete context of the ARTFL database, demonstrates the feasibility of this approach. Some of its advantages and disadvantages are described. 1 Introduction and Motivation What programming languages are most appropriate for writing Information Retrieval Systems? This question has been very little discussed, but it is one of enormous practical importance. It seems that most working systems are implemented in low-level languages such as C, or even Assembly language, because their designers tend to think that the aspects of retrieval systems which are most crucial to performance, such as input/output, are best controlled by a low-level language. We suggest that high-level..

Report of the EAGLES Workshop on Implemented Formalisms at DFKI, Saarbrucken

ions An extension of the PATR-II `template' facility to form a constraint language closely resembling Prolog, but without the extralogical devices of that language (`cut', negation, conditionals, `assert', `var', etc.). Proc(A,B,C) three arguments !A f? = [B---D] B head of a list value !Proc2(C,D) call to another R.A. Relational abstractions may be defined recursively and/or in terms of multiple subclauses; in the latter case evaluation involves breadth-first expansion of all possibilities, while in the former evaluation is suspended as long as insufficient information is available to identify the boundary case. ELU 51 Built-in Relations A number of useful three-place relations are provided, using a specialized notation: Append A ++ B = C C is the result of appending the lists A and B. Extract A -- B = C C is the result of extracting the element B from the list A. Concatenate A && B = C C is the result of concatenating the strings A and B. Restrictors Users may declare certai..