Pertti Vakkari

Task complexity, problem structure and information actions: integrating studies on information seeking and retrieval

Analyzing actions to be supported by information and information retrieval (IR) systems is vital for understanding the needs of different types of information, search strategies and relevance assessments, in short, understanding IR. A necessary condition for this understanding is to link results from information seeking studies to the body of knowledge by IR studies. The actions to be focused on in this paper are tasks from the angle of problem solving. I will analyze certain features of work tasks and relate these features to types of information people are looking for and using in their tasks, patterning of search strategies for obtaining information and relevance assessments in choosing retrieved documents. The major claim is that these information activities are systematically connected to task complexity and structure of the problem at hand. The argumentation is based on both theoretical and empirical results from studies on information retrieval and seeking.

A theory of the task‐based information retrieval process: a summary and generalisation of a longitudinal study

The aim of this article is threefold: (1) to give a summary of empirical results reported earlier on relations between students‘ problem stages in the course of writing their research proposals for a master’s thesis and the information sought, choice of search terms and tactics and relevance assessments of the information found for that task; (2) to show how the findings of the study refine Kuhlthau‘s model of the information search process in the field of information retrieval (IR); and (3) to construe a tentative theory of a task‐based IR process based on the supported hypotheses. The results of the empirical studies show that there is a close connection between the students’ problem stages (mental model) in the task performance and the information sought, the search tactics used and the assessment of the relevance and utility of the information found. The corroborated hypotheses expand the ideas in Kuhlthau‘s model in the domain of IR. A theory of task‐based information searching based on the empirical findings of the study is presented.

Changes in relevance criteria and problem stages in task performance

The objective of this study is to analyse how changes in relevance criteria are related to changes in problem stages during the task performance process. Relevance is understood as a task‐ and process‐oriented user construct. The assessment of relevance is based on both retrieved bibliographical information and the documents acquired and read on the basis of this information. The participants of the study were eleven students who attended a course for one term for preparing a research proposal for the master’s thesis. The students were asked to make an IR search at the beginning, middle and end of the course. Data for describing their understanding of the work task, search goals and tactics as well as relevance assessments were collected during the search sessions. Pre‐ and post‐search interviews were conducted during each session. The students were asked to think aloud during the search session. The transaction logs were captured and the thinking aloud was recorded. Research and search diaries were also collected. The findings support to a certain extent the overall hypotheses that a person’s problem stage during task performance is related to his or her use of relevance criteria in assessing retrieved references and documents. There is a connection between an individual’s changing understanding of his or her task and how the relevance of references and full texts is judged. The more structured the task in the process, the more able the person is to distinguish between relevant and other sources. The relevance criteria of documents changed more than the criteria of references during the process. Moreover, it seems that understanding of topicality varies depending on the phase of the process.

The evolution of library and information science 1965–1985: a content analysis of journal articles

Abstract A content analysis of the research of library and information science (LIS) from 1965 to 1985 is reported. The aim is to find out how international research in LIS is distributed over topics, and what approaches and methods have been used to investigate these topics. The study samples consist of 142, 359, and 449 full-length research articles published in 1965, 1975, and 1985, respectively, in core LIS journals. The proportion of library and information service activities, and information storage and retrieval among the topics of the research articles was each 25% to 30% through the years. There was very little research on methodology (1%–8%), information seeking (6%–8%), and scientific communication (5%–7%). The proportion of empirical research strategies was high (49%–56%) with survey method (20%–23%) as the single most important method. A conceptual research strategy (mainly verbal argumentation) was employed in 23%–29% of the articles and system analysis, description and design in 10%–15%. The most remarkable changes from 1965 to 1985 are the loss of interest in methodology and in the analysis of LIS and the change of interest in information storage and retrieval from classification and indexing (from 22% to 6%) to retrieval (from 4% to 13%). Cross-tabulations of article topics with research strategies and approaches are presented.

Subject knowledge improves interactive query expansion assisted by a thesaurus

This study explores how experts and novices in pedagogics expanded queries supported by the ERIC thesaurus, and how this was connected to the search effectiveness in an easy and a difficult search task. The expert group consisted of 15 undergraduates in pedagogy and the novice group of 15 students with no previous studies in this field. Their search logs were recorded and a pre‐ and post‐search interview was conducted. The results show that the number and type of terms selected from the thesaurus for expansion by experts improved search effectiveness, whereas there were no connections between the use of thesaurus and improvement of effectiveness among novices. The effectiveness of expansions varied between the facets of the queries. Thus, a vital condition for benefiting from a thesaurus in query expansion to improve search results is sufficient familiarity with the search topic. The results suggest also that it is not in the first place the number of terms used in expansion, but their type and quality that are crucial for search success.

Relevance and contributing information types of searched documents in task performance

End-users base the relevance judgements of the searched documents on the expected contribution to their task of the information contained in the documents. There is a shortage of studies analyzing the relationships between the experienced contribution, relevance assessments and type of information initially sought. This study categorizes the types of information in documents being used in writing a research proposal for a masters thesis by eleven students throughout the various stages of the proposal writing process. The role of the specificity of the searched information in influencing its contribution is analyzed. The results demonstrate that different types of information are sought at different stages of the writing process and thus the contribution of the information also differs at the different stages. The categories of the contributing information can be understood of topicality.

Growth of theories on information seeking: an analysis of growth of a theoretical research program on the relation between task complexity and information seeking

The aim of this article is to analyse the growth of a theoretical research program in the field of information needs and seeking studies. The program consists of a set of interrelated studies on the effects of task complexity on information source use. The growth is assessed by reconstructing the logical structure of the theories within the program and by comparing those reconstructions in terms of their conceptual and factual similarity. The growth pattern is then analysed by using Wagners and Bergers model of theory growth from sociology. The analysis reveals the growth pattern of the program. The results indicate that the chosen program is progressive in terms of empirical support and precision of the theories, and that the growth pattern is elaborative. Moreover, based on the analysis consequences for further studies are presented.

Evolution of library and information science, 1965–2005: Content analysis of journal articles

This article first analyzes library and information science (LIS) research articles published in core LIS journals in 2005. It also examines the development of LIS from 1965 to 2005 in light of comparable data sets for 1965, 1985, and 2005. In both cases, the authors report (a) how the research articles are distributed by topic and (b) what approaches, research strategies, and methods were applied in the articles. In 2005, the largest research areas in LIS by this measure were information storage and retrieval, scientific communication, library and information‐service activities, and information seeking. The same research areas constituted the quantitative core of LIS in the previous years since 1965. Information retrieval has been the most popular area of research over the years. The proportion of research on library and information‐service activities decreased after 1985, but the popularity of information seeking and of scientific communication grew during the period studied. The viewpoint of research has shifted from library and information organizations to end users and development of systems for the latter. The proportion of empirical research strategies was high and rose over time, with the survey method being the single most important method. However, attention to evaluation and experiments increased considerably after 1985. Conceptual research strategies and system analysis, description, and design were quite popular, but declining. The most significant changes from 1965 to 2005 are the decreasing interest in library and information‐service activities and the growth of research into information seeking and scientific communication.

Subject Knowledge, Source of Terms, and Term Selection in Query Expansion: An Analytical Study

The role of subject and search knowledge in query expansion (QE) is an unmapped terrain in research on information retrieval. It is likely that both have an impact on the process and outcome of QE. In this paper our aim is an analytical study of the connections between subject and search knowledge and term selection in QE based both on thesaurus and relevance feedback. We will also argue analytically how thesaurus, term suggestion in interactive QE and term extraction in automatic QE support users with differing levels of subject knowledge in their pursuit of search concepts and terms. It is suggested that in QE the initial query concepts representing the information need should not be treated as separate entities, but as conceptually interrelated. These interrelations contribute to the meaning of the conceptual construct, which the query represents, and this should be reflected in the terms identified for QE.

Theory growth in information science: applications of the theory of science to a theory of information seeking

The aim of the study is to analyse theory growth in information science by using a case from information seeking studies. Scientific growth is identified with the growth of theories. Three contexts of theoretical work are differentiated: unit theories, theoretical research programmes and metatheories. For analysis of theory growth tools based on the current theory of science are needed. The study introduces tools for the analysis of theory growth and theory reconstruction and applies them to analysis of a theory on information seeking. Tools include the systematisation and formalisation of theories. The usefulness of these tools is illustrated by reconstructing a theory used in a current information seeking study. It is shown that they help in specifying the theory in the following ways: 1. in stating the central concepts and their relations; 2. in revealing implicit restrictions of the theory; and 3. in facilitating the derivation of additional hypotheses from the theory’s axioms, especially by showing the mechanisms which interconnect the concepts of the theory. The results of reconstruction, specification and enrichment of the theory show future prospects for developing it and thus it creates potential growth of knowledge within the theory of information seeking.