Encyclopedia of Database Systems

2018 Edition
| Editors: Ling Liu, M. Tamer Özsu

Success at n

  • Nick CraswellEmail author
Reference work entry
DOI: https://doi.org/10.1007/978-1-4614-8265-9_485




Success at n is an information retrieval relevance measure, equal to 1 if the top-n documents contain a relevant document and 0 otherwise. When averaged across multiple queries, the success rate at n indicates how often something relevant was retrieved within the top-n.

Key Points

A system with a high success rate will be one that rarely retrieves zero relevant documents. Therefore, success rate can be employed to monitor failure. The success rate of two systems may differ even if they have the same mean precision at n, because one system has higher variance than the other. Success at n models the satisfaction of a user who does not need to see many relevant documents, is prepared to view up to n results and is disappointed by a completely irrelevant top-n.


Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Microsoft Research CambridgeCambridgeUK

Section editors and affiliations

  • Weiyi Meng
    • 1
  1. 1.Dept. of Computer ScienceState University of New York at BinghamtonBinghamtonUSA