Goodhart’s Law


An observation made in 1975 by Charles Goodhart, Chief Adviser to the Bank of England, that statistical economic indicators, when used for regulation, become unreliable. Restated and generalized in 1997 by University of Cambridge Professor Marilyn Strathern as “When a measure becomes a target, it ceases to be a good measure.” Within the context of Electronic Discovery, Goodhart’s Law suggests that the value of Information Retrieval measures such as Recall and Precision may be compromised if they are prescribed as the definition of the reasonableness of a search or review effort. 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).