Information retrieval is currently an active research field with the evolution of World wide web. The objective of this chapter is to provide an insight into the information retrieval definitions, process, models. Further how traditional information retrieval has evolved and adapted for search engines is also discussed. The information retrieval models have not only been used for search purpose it also supports cross lingual translation and retrieval tasks. This chapter also outlines the CLIR process in a brief manner. The tools which are usually used for experimental and research purpose is also discussed. This chapter is organized as Introduction to the concepts of information retrieval. Description of the information retrieval process, the information retrieval models, the role of external sources like ontologies in information retrieval systems. Finally the chapter provides an overview of CLIR and the tools used in developing IR systems is mentioned. Further the latest research directions in IR is explained.
TopIntroduction
Information retrieval(IR) is a field concerned with structure, analysis, storage, organization searching and retrieval of information[Salton,1968]. With the abundant growth of information of web the information retrieval models proposed for retrieval of text documents from books in early 1960’s has gained greater importance and popularity among information retrieval scientist and researchers. Today search engine is driven by these information retrieval models.
The fundamental research of information retrieval system focused on searching and retrieving documents relevant to the user information need expressed in the form of query. The challenge lies in retrieving most relevant documents from large corpus by processing the unstructured query. Eventually the information retrieval systems have been designed and researched for retrieving non textual content like video, images, audio and music.
The major issues in IR research is
This chapter is organized as five sections Section I introduces the concepts of information retrieval. Section II describes the information retrieval process. Section III outlines the information retrieval models; Section IV explains the role of external sources like ontologies in information retrieval systems. Section V provides an overview of CLIR and finally the tools used in developing IR systems is mentioned. Further the latest research directions in IR is explained
TopDefinition 1 [Salton, 1968]
Information retrieval is a field concerned with the structure, analysis, organization, storage, searching, and retrieval of information.
Definition 2 [Christopher Manning et Al., 2009]