Skip to main content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.


The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

The History of IDF and its Influences on IR and Other Fields



Donna K. Harman


The surprisingly simple IDF measure developed in 1972 by Karen Sparck Jones has continued to dominate the term weighting metrics used in information retrieval, despite several efforts to develop more complex measures of term distribution. It has been incorporated in (probably) all information retrieval systems and used in languages other than English. This chapter presents the origins of the IDF measure and how it evolved into the measure that is used today.
Progress in Natural Language Processing & Information Retrieval: A Festschrift for Karen Sparck Jones
Publisher Info


IDF, term waiting
Created December 21, 2005, Updated February 19, 2017