If you are estimating a parameter with a sample statistic, two properties it should have are unbiasedness and low variance: https://en.wikipedia.org/wiki/Minimu

If you are estimating a parameter with a sample statistic, two properties it should have are unbiasedness and low variance: https://en.wikipedia.org/wiki/Minimum-variance_unbiased_estimator https://en.wikipedia.org/wiki/Minimum-variance_unbiased_esti...