Spring 2009 CSC 466 : Knowledge Discovery from Data

Definitions Information Retrieval (IR). The process of finding documents from a given document collection that are relevant to the user's query. Document collections. The key assumption of IR is that document collections are large. Note: This is not always the case. There are some specialized uses of IR techniques, where the document collections are on the order of tens or hunderds of documents, not hundreds of thousands/millions as is usual for traditional IR settings. Queries. A user query is a formal representation of an information need. The two are not the same. An information need is an articulated desire to obtain certain information (or to find documents that contain certain information). A query is a representation of an information need that can be processed by the specific Information Retrieval system. Example. The user information need is to find all information about the University of Alabama's 1992 football season, in particular, to find the list of all games. The user query to a search engine (google) can be: "University of Alabama Crimson Tide football 1992 season games schedule". (Given this query, Google returns the wikipedia page on the 1992 Alabama football season, with the list of games as the top page).