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

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It is nowadays generally agreed that a person's information seeking depends on her tasks and the problems encountered in performing them. The relationships of broad job types and information seeking characteristics have been analyzed both conceptually and empirically, mostly through questionnaires after task performance rather than during task performance. In this article, the relationships of task complexity, necessary information types, information channels and sources are analyzed at the task level on the basis of a qualitative investigation. Tasks were categorized in five complexity classes and information into problem information, domain information and problem solving information. Moreover, several classifications of information channels and sources were utilized. The data were collected in a public administration setting through diaries, which were written during task performance, and questionnaires. The findings were structured into work charts for each task and summarized in qualitative process description tables for each task complexity category. Quantitative indices further summarizing the results were also computed. The findings indicate systematic and logical relationships between task complexity, types of information, information channels and sources.

Designing good user interfaces to information retrieval systems is a complex activity. The design space is large and evaluation methodologies that go beyond the classical precision and recall figures are not well established. In this paper we present an evaluation of an intelligent interface that covers also the user-system interaction and measures user's satisfaction. More specifically, we describe an experiment that evaluates: (i) the added value of the semiautomatic query reformulation implemented in a prototype system; (ii) the importance of technical, terminological, and strategic supports and (iii) the best way to provide them. The interpretation of results leads to guidelines for the design of user interfaces to information retrieval systems and to some observations on the evaluation issue.

The support of effective interaction of the user with the other components of the system is a central problem for information retrieval. In this paper, we present a theory of such interactions taking place within a space of information-seeking strategies, and discuss how such a concept can be used to design for effective interaction. In particular, we propose a model of information retrieval system design based on the ideas of: a multi-dimensional space of information-seeking strategies; dialogue structures for information seeking; cases of specific information-seeking dialogues; and, scripts as distinguished prototypical cases. We demonstrate the use of this model by discussing in some detail the MERIT system, a prototype information retrieval system which incorporates these design principles.

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We present an analysis of information retrieval as an information-seeking activity, supporting people's interactions with text. This analysis suggests that some assumptions underlying the standard model of information retrieval are inappropriate, and we suggest alternative assumptions and discuss their implications for information retrieval system design. It is proposed that information retrieval is most properly considered as information-seeking behavior, that the central process of information retrieval is user interaction with text, and that the user is the central component of the information retrieval system. Possible ways to incorporate this view in the design of information retrieval systems are discussed.

The imact of NLP on information retrieval tasks has largely been one of promise rather than substance. While there are exceptions to this as some of the chapters in the present volume demonstrate, for the most part NLP and information retrieval have only recently started to dovetail together. In this chapter we will present a pr'ecis of our experiments in information retrieval using NLP which have had mixed successover the last few years. We introduce the respective roles of NLP and IR and then we summarise our early experiments on using syntactic analysis to derive term dependencies and structured representations of term-term relationships. We then re-thought the role that NLP could have for IR tasks and decided to concentrate our efforts onto using NLP resources rather than NLP tools in information retrieval and our more recent experiments in this area in which we use WordNet are summarised. Finally we present our conclusions and the status of our work. 1 2. Introduction The develo...

Web search services are now a major source of information for a growing number of people. We need to know more about how users search Web search engines to improve the effectiveness of their information retrieval. This paper reports results from a major study exploring users ’ information searching behavior on the EXCITE Web search engine. The study is the first to investigate Web users ’ successive searching behavior as they conduct related searches over time on the same or evolving topic. A total of 316 EXCITE users responded to an interactive survey accessed through EXCITE’s homepage. Users provided information on their search topics, intended query terms, search frequency for information on their topic, and demographic data. Results show that when searching the Web: users tend to employ simple search strategies; and often conduct more than one search (successive searches) over time to find information related to a particular topic. Implications for the design of Web search services are discussed.

This article proposes a model of document selection by IR system by incorporating users ’ document selection and real users of a bibliographic retrieval system. It reports on Part 1 of a longitudinal study of decision making on document use by academics during an actual research project. (Part 2 followed up the same users on how the use behavior. Document selection is the endpoint of a bibliographic search. From there, the selected document may proceed selected documents were actually used in subsequent to the next stage: document use (reading and citing). stages.) The participants are 25 self-selected faculty and Figure 1 depicts three major decision points of document graduate students in Agricultural Economics. After a ref- use along the stages of document seeking and use during erence interview, the researcher conducted a search of DIALOG databases and prepared a printout. The users a research project. The solid box indicates the process in selected documents from this printout; they were asked which the decision about a retrieved document is made. to read and think aloud while selecting documents. Their The dotted box depicts the decisions about reading and verbal reports were recorded and analyzed from a utilitytheoretic perspective. The following model of the decision-making in the selection process emerged: docu-ment information elements (DIEs) in document records citing the retrieved document in later stages; reading and citing interweave. This research aims at the decision making processes across these different stages in a real life provide the information for judging documents on 11 cri-situation. teria (including topicality, orientation, quality, novelty, Previous studies that have examined real users on and authority); the criteria judgments are combined in either document selection or citation motivations are, an assessment of document value along five dimensions (epistemic, functional, conditional, social, and emotional among others, Barry (1993), Bonzi and Snyder (1991), values), leading to the use decision. This model ac-