What is Inverse Document Frequency (IDF)

This chapter is about documents and data clustering as a process of preparing the information resources stored in the e-government systems for advanced search. These resources are mainly represented as textual data stored as field values in the databases or located as documents in file repositories. Due to their growth in number, search for some specific information takes more time. Different techniques are used for this purpose. Most of them include information retrieval based on a variety of text similarity measures. The cost of such processing depends on preparation of resources for searching. Clustering represents the most commonly used technique for such a purpose, and this fact is the basic motive for this chapter.