Finding Out About explains how to build useful tools for searching collections of text and other media. In the process it takes a close look at the properties of textual documents that do not become clear until very large collections of them are brought together and shows that the constructions of effective search engines requires knowledge of the statistical and mathematical properties of linguistic phenomena, as well as an appreciation for the cognitive foundation we bring to the task as language users. The unique approach of this book is its even handling of the phenomena of both numbers and words, giving it a wide appeal. The textbook works for undergraduate and graduate classes on information retrieval, library science, and computational linguistics. More exercises are available to instructors. A supporting Web site includes recent additions to the book, as well as links to sites of new topics and methods.