The objective of the paper is to amalgamate theories of text retrieval from various research traditions into a cognitive theory for information retrieval interaction. Set in a cognitive framework, the paper outlines the concept of polyrepresentation applied to both the user's cognitive space and the information space of IR systems. The concept seeks to represent the current user's information need, problem state, and domain work task or interest in a structure of causality. Further, it implies that we should apply different methods of representation and a variety of IR techniques of different cognitive and functional origin simultaneously to each semantic full-text entity in the information space. The cognitive differences imply that by applying cognitive overlaps of information objects, originating from different interpretations of such objects through time and by type, the degree of uncertainty inherent in IR is decreased. Polyrepresentation and the use of cognitive overlaps are associated with, but not identical to, data

Abstract. We describe WEST, a WEb browser for Small Terminals, that aims to solve some of the problems associated with accessing web pages on hand-held devices. Through a novel combination of text reduction and focus+context visualization, users can access web pages from a very limited display environment, since the system will provide an overview of the contents of a web page even when it is too large to be displayed in its entirety. To make maximum use of the limited resources available on a typical hand-held terminal, much of the most demanding work is done by a proxy server, allowing the terminal to concentrate on the task of providing responsive user interaction. The system makes use of some interaction concepts reminiscent of those defined in the Wireless Application Protocol (WAP), making it possible to utilize the techniques described here for WAP-compliant devices and services that may become available in the near future. Keywords. Hand-held devices, web browser, proxy systems, focus+context visualization, text reduction, flip zooming, WAP (wireless application protocol) 1

This paper presents domain-independent methods of spoken document retrieval. Both a continuous-speech large vocabulary recognition system, and a phone-lattice word spotter, are used to locate index units within an experimental corpus of voice messages. Possible index terms are nearly unconstrained; terms not in a 20,000 word recognition system vocabulary can be identified bytheword spotter at search time. Though either system alone can yield respectable retrieval performance, the two methods are complementary and work best in combination. Different ways of combining them are investigated, and it is shown that the best of these can increase retrieval average precision for a speaker-independent retrieval system to85% of that achieved for full-text transcriptions of the test documents.

Information retrieval systems are built to handle texts as topical items: texts are tabulated by occurrence frequencies of content words in them, under the assumption that text topic is reasonably well modeled by content word occurrence. But texts have several interesting characteristics beyond topic. The experiments described in this text investigate stylistic variation. Roughly put, style is the difference between two ways of saying the same thing -- and systematic stylistic variation can be used to characterize the genre of documents. These experiments investigate if stylistic information is distinguishable using simple language engineering methods, and if in that case this type of information can be used to improve information retrieval systems.

Automatic summarisation of spoken audio is a fairly new research pursuit, in large part due to the relative novelty of technology for accurately decoding audio into text. Techniques that account for the peculiarities and potential ambiguities of decoded audio (high error rates, lack of syntactic boundaries) appear promising for culling summary information from audio for content-based browsing and skimming. This paper combines acoustic confidence measures with simple information retrieval and extraction techniques in order to obtain accurate, readable summaries of broadcast news programs. It also demonstrates how extracted summaries, full-text speech recogniser output and audio files can be usefully linked together through an audio-visual interface. The results suggest that information extraction based on statistical information can produce viable summaries of decoded audio. 1. APPLICATION CONTEXT Managing this contemporary explosion of audio and video materials calls for intelligent s...

this paper; comparisons between passage and non-passage runs can be seen in a few of the tables.

This paper describes a spoken document retrieval (SDR) system for British and North American Broadcast News. The system is based on a connectionist large vocabulary speech recognizer and a probabilistic information retrieval system. We discuss the development of a realtime Broadcast News speech recognizer, and its integration into an SDR system. Two advances were made for this task: automatic segmentation and statistical query expansion using a secondary corpus. Precision and recall results using the Text Retrieval Conference (TREC) SDR evaluation infrastructure are reported throughout the paper, and we discuss the application of these developments to a large scale SDR task based on an archive of British English broadcast news. Keywords: Spoken Document Retrieval; Information Retrieval; Broadcast Speech; Large Vocabulary Speech Recognition. 1 Introduction Retrieval of audio segments according to their content is a challenging and significant problem. It has been estimated th...

ueries using all search facets identified from requests, low complexity was achieved by formulating queries with major facets only. Query expansion was based on a thesaurus, from which the expansion keys were elicited for queries. There were five expansion types: (1) the first query version was an unexpanded, original query with one search key for each search concept (original search concepts) elicited from the test thesaurus; (2) the synonyms of the original search keys were added to the original query; (3) search keys representing the narrower concepts of the original search concepts were added to the original query; (4) search keys representing the associative concepts of the original search concepts were added to the original query; (5) all previous expansion keys were cumulatively added to the original query. Query structure refers to the syntactic structure of a query expression, marked with query operators and parentheses. The structure of queries was either weak (queries with n

This paper examines the use of generic summaries for indexing in information retrieval. Our main observations are that: (1) With or without pseudo-relevance feedback, a summary index may be as eective as the corresponding fulltext index for precision-oriented search of highly relevant documents.

We examine the search of partitioned inverted files with particular emphasis on issues that arise from different types of partitioning methods. Two types of index partitions are investigated: namely Termld and Docld. We describe the search operations implemented in order to support parallelism in probabilistic search. We also describe higher level features such as search topologies in parallel search methods. The results from runs on the two types of partitioning are compared and contrasted. We conclude that within our framework the Docld method is the best. 1.