The definition of an MSE differs according to whether one is. Free from all prejudice and favoritism. Definition An estimator is said to be unbiased if and only if where the expected value is calculated with respect to the probability distribution of the sample.
Examples of Unbiased Sample.
The bias of an estimator is the difference between this estimators expected value and the true value of the parameter being estimated. Where X is the sample mean. Of an estimator having an expected value equal to the parameter being estimated. Illustrated definition of Bias.