An introduction to web scale discovery systems.

This article explores the basic principles of web-scale discovery systems and how they are being implemented in libraries. "Web scale discovery" refers to a class of products that index a vast number of resources in a wide variety formats and allow users to search for content in the physical collection, print and electronic journal collections, and other resources from a single search box. Search results are displayed in a manner similar to Internet searches, in a relevance ranked list with links to online content. The advantages and disadvantages of these systems are discussed, and a list of popular discovery products is provided. A list of library websites with discovery systems currently implemented is also provided.