A number of metaphors have been invoked to explain how to bring people together with the information they need. Information retrieval presumes that the information has been stored in an orderly structure, in which it can be looked up. Data mining views it as latent, scattered among irrelevant dross from which it must be extracted. Information farming expects that the information does not yet exist, but that it can be coaxed into existence by manipulating the institutions that have the power to generate it, as a farmer coaxes crops out of seeds, soil, sun, and water.
Pirolli’s innovative monograph introduces yet another metaphor, that of an animal foraging for food. Like any metaphor, this one suggests some useful perspectives on the problem: information is disorganized (as in data mining, but not information retrieval), it can be associated with a “scent” that guides users to it, and users’ desire to search further decreases as their appetite is sated. In addition to these informal insights, the work provides a point of contact with research in mathematical ecology into formal models of animal foraging behavior. Much of the progress of science has come from transferring insights derived in one discipline to another by way of an insightful analogy. Information foraging is a very promising instance of this historic process.
The first two chapters of Pirolli’s work introduce the metaphor, survey the related biological research, and introduce the methodological approach. The methodology is based on Anderson’s notion of rational analysis, which focuses on the structure of the task at hand rather than observed behaviors. This analysis forms the basis for construction of a series of production-rule models of task execution in various derivatives of the adaptive control of thought--rational (ACT-R) environment, and comparisons between these models and observed human performance occupy much of the remainder of the book.
Chapter 3 reports on some early quantitative analyses of how users search for information on the Web, and chapter 4 offers a rational analysis of Web foraging based on the notion of “information scent,” clues in the environment (the page currently viewed by a user) as to where to look for further information. A spreading activation process propagates information among cognitive structures representing cues available in the environment.
Chapters 5 and 6 implement cognitive models of information gathering in the ACT-R framework, and compare their behavior with human subjects. Chapter 5 models general information foraging, while chapter 6 models the scatter-gather document browser. Chapter 7 introduces an alternative approach to studying information foraging: stochastic models implemented as Markov processes.
Thus far, the book has been concerned with a single user seeking information. Chapter 8 discusses information foraging that takes place in a community, where one user’s actions may contribute to another user’s search process. Chapter 9 summarizes the study’s applications in the form of design recommendations for information systems. Chapter 10 identifies future areas of research stimulated by this study.
The book’s references are organized by chapter, not as a single integrated bibliography, but there is an integrated index to researcher names, as well as a comprehensive subject index. The volume is a careful, competent exposition of a novel approach to bringing people together with the information they need, and merits careful attention by the information science community.
