The fraction (The fraction of a set of Documents having some particular property (typically Relevance).) of times that a particular outcome would occur, should the same action be repeated under the same conditions an infinite number of times. For example, if one were to flip a fair coin, the Probability of it landing “heads” is one-half, or 50%; as one repeats this action indefinitely, the fraction of times that the coin lands “heads” will become indistinguishable from 50%. If one were to flip two fair coins, the Probability of both landing “heads” is one-quarter, or 25%. 1


  1. Maura R. Grossman and Gordon V. Cormack, EDRM page & The Grossman-Cormack Glossary of Technology-Assisted Review, with Foreword by John M. Facciola, U.S. Magistrate Judge2013 Fed. Cts. L. Rev. 7 (January 2013).