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EFFICIENCY (IN STATISTICAL ESTIMATION)

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French Equivalent: Efficacité

Definition:
The concept of efficiency in statistical estimation is due to Fisher (1921) and is an attempt to measure objectively the relative merits of several possible estimators.

Context:
The criterion adopted by Fisher was that of variance, an estimator being regarded as more “efficient” than another if it has smaller variance; and if there exists an estimator with minimum variance v the efficiency of another estimator of variance v1 is defined as the ration v/v1.

It was implicit in this development that the estimator should obey certain other criteria such as consistency. For small samples, where other considerations such as bias enter, the concept of efficiency may require extension or modification.

The word is also used to denote the properties of experimental designs, one design being more efficient than another if it secures the same precision with less expenditure of time or money.

Source Publication:
A Dictionary of Statistical Terms, 5th edition, prepared for the International Statistical Institute by F.H.C. Marriott. Published for the International Statistical Institute by Longman Scientific and Technical.

Statistical Theme: Methodological information (metadata)

Created on Tuesday, May 21, 2002

Last updated on Monday, April 28, 2003