Information Retrieval Essay

ABSTRACT:

Information Retrieval deals with the representation, storage, organization of and access to Information items. The evaluation of an information retrieval system is the process of assessing how well a system meets the information needs of its users. Information retrieval (IR) systems use a simpler data model than database systems. Information organized as a collection of documents. The effective retrieval of relevant information is directly affected both by the user task and by the logical view of the documents adopted by the retrieval system. Information Retrieval (IR) is the method that contract with retrieval of unstructured data mainly textual documents, in response to a query or topic statement, which may itself be unstructured.

Query does not uniquely identify a single object in the collection but are instead represented in the system by document surrogates or metadata. The systematic storage and recovery of data as from a file card catalogue or the memory bank of a computer. Information retrieval consists of 4 main stages identifying the exact subject of the search, locating this subject in a guide which refers the searcher to one or more documents, locating the documents, locating the required information in the documents. Entity is identified as object which is represented by information in a database. Queries which are sent by user are matched against database information. The evaluation of an information retrieval system is the process of assessing how well a system meets the information needs of its users. Information retrieval (IR) systems use a simpler data model than database systems. Information organized as a collection of

Such a process is interpreted in terms of component sub processes whose study yields many of the chapters in this book.

To describe the retrieval process, we use a simple and generic software architecture as shown in Figure . First of all, before the retrieval process can even be initiated, it is necessary to define the text database. This is usually done by the manager of the database, which specifies the following:

(a) the documents to be used,

(b) the operations to be performed on the text, and

(c) the text model (i.e., the text structure and what elements can be retrieved). The text operations transform the original documents and generate a logical view of them.

Once the logical view of the documents is defined, the database manager (using the DB Manager Module) builds an index of the text. An index is a critical data structure because it allows fast searching over large volumes of data. Different index structures might be used, but the most popular one is the inverted file as indicated in Figure . The resources (time and storage space) spent on defining the text database and building the index are amortized by querying the retrieval system many