The paper develops a behavioral model of Web information seeking that identifies four complementary modes of information seeking: undirected viewing, conditioned viewing, informal search, and formal search. In each mode of viewing or searching, users would adopt distinctive patterns of browser moves: starting, chaining, browsing, differentiating, monitoring, and extracting. The model is applied empirically to analyze the Web information seeking behavior of 24 women in IT professions over a two-week period. Our results show that participants engaged in all four modes of information seeking on the Web, and that each mode may be characterized by certain browser actions. Overall, the study suggests that a behavioral approach that links information seeking modes (goals and reasons for browsing and searching) to moves (actions used to find and view information) may be helpful in understanding Web-based information seeking.