Jackknife

Jackknife is a classical technique in estimating theory which has two major purposes: Reducing the bias of a given estimator and Reducing of confidence intervals

Tukey who invented it and named in jackknife has idea that this technique could serve as and puropose tool for constructing an all purpose statistical tool for constructing confidence intervals. Just like a boy scout uses his jackknife as a versatile tool in a wide variety of situation.

Jackknife statistics are created by systematically dropping out subsets of data one at a time and assessing the resulting variation in the studied parameter.