Pooled Variance - Unbiased Least Square Estimate Vs. Biased Maximum Likelihood Estimate

Unbiased Least Square Estimate Vs. Biased Maximum Likelihood Estimate

Both

and

are used in different contexts. The former can give an unbiased to estimate when the two groups share an equal population variance. The latter one can give a more efficient to estimate biasedly. Note that the quantities in the right hand sides of both equations are the unbiased estimates.

Read more about this topic:  Pooled Variance

Famous quotes containing the words unbiased, square, estimate, biased, maximum and/or likelihood:

    Where there is no exaggeration there is no love, and where there is no love there is no understanding. It is only about things that do not interest one, that one can give a really unbiased opinion; and this is no doubt the reason why an unbiased opinion is always valueless.
    Oscar Wilde (1854–1900)

    Houses haunt me.
    That last house!
    How it sat like a square box!
    Anne Sexton (1928–1974)

    Let man consider what he is in comparison with all existence; let him regard himself as lost in this remote corner of nature; and from the little cell in which he finds himself lodged, I mean the universe, let him estimate at their true value the earth, kingdoms, cities, and himself. What is a man in the infinite?
    Blaise Pascal (1623–1662)

    Scientists are human—they’re as biased as any other group. But they do have one great advantage in that science is a self-correcting process.
    Cyril Ponnamperuma (b. 1923)

    Only at his maximum does an individual surpass all his derivative elements, and become purely himself. And most people never get there. In his own pure individuality a man surpasses his father and mother, and is utterly unknown to them.
    —D.H. (David Herbert)

    What likelihood is there of corrupting a man who has no ambition?
    Samuel Richardson (1689–1761)