Most books on human-computer interaction (HCI) and usability give recommendations based on empirical research, guidelines fit to observed user behavior, and cognitive models after the fact. Peter Pirolli, the father of information foraging theory, has written a new book that models and predicts what users will do before they navigate a website. Using mathematical models of human behavior, Pirolli lays out the foundation of information foraging theory, a relatively new field based in part on optimal foraging theory in animals (Stephens & Krebs 1986). The result is a seminal work in Oxford University Press’ series on Human-Computer Interaction. We were fortunate to review a proof of Pirolli’s new book Information Foraging Theory: Adaptive Interaction with Information, due out April 2007.