While information retrieval was developed within the librarians’ community well before the use of computers, its importance boosted at the turn of the century, with the diffusion of the World Wide Web. Big players in the computer industry, such as Google and Yahoo!, were the primary contributors of a technology for fast access to Web information. Searching capabilities are now integrated in most information systems, ranging from business management software and customer relationship systems to social networks and mobile phone applications. The technology for searching the Web is thus an important ingredient of computer science education that should be offered at both the bachelor and master levels, and is a topic of great interest for the wide community of computer science researchers and practitioners who wish to continuously educate themselves.
This book covers the needs of a short (3–5 credit) course on information retrieval. It is focused on the Web, but it starts with Web-independent foundational aspects that should be known as required background; therefore, the book is self-contained and does not require the student to have prior background. It can also be used in the context of classic (5–10 credit) courses on database management, thus allowing the instructor to cover not only structured data, but also unstructured data, whose importance is growing. This trend should be reflected in computer science education and curricula.