The goal of this work is to provide a fundamental understanding of the daily information needs of people through a large-scale, in-depth, quantitative investigation. To this end, we have conducted one of the most comprehensive studies of information needs to date, spanning a 3-month period and involving more than 100 users. The study employed a contextual experience sampling method, a snippet-based diary technique using SMS technology, and an online Web diary to gather in situ insights into the types of needs that occur from day to day, how those needs are addressed, and how contextual, technological, and demographic factors impact on those needs. Our results not only complement earlier studies but also provide a new understanding of the intricacies of people's daily information needs.