Estimator

In statistics, an estimator is a rule for calculating an estimate of a given amount based on observed data. The rule (the estimator), the amount that is being measured (the estimand) and its result (the estimate) are different.

An estimator of a parameter  is often written as . If the expected value of the estimator is equal to the parameter, then the estimator is called unbiased. Otherwise, it is called biased.

 Related pages 

 Efficiency (statistics)

References

Other websites
Fundamentals on Estimation Theory  

Category:Statistics