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:

    There is not a more disgusting spectacle under the sun than our subserviency to British criticism. It is disgusting, first, because it is truckling, servile, pusillanimous—secondly, because of its gross irrationality. We know the British to bear us little but ill will—we know that, in no case do they utter unbiased opinions of American books ... we know all this, and yet, day after day, submit our necks to the degrading yoke of the crudest opinion that emanates from the fatherland.
    Edgar Allan Poe (1809–1845)

    Rationalists, wearing square hats,
    Think, in square rooms,
    Looking at the floor,
    Looking at the ceiling.
    They confine themselves
    To right-angled triangles.
    Wallace Stevens (1879–1955)

    The man possessed of a dollar, feels himself to be not merely one hundred cents richer, but also one hundred cents better, than the man who is penniless; so on through all the gradations of earthly possessions—the estimate of our own moral and political importance swelling always in a ratio exactly proportionate to the growth of our purse.
    Frances Wright (1795–1852)

    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)

    I had a quick grasp of the secret to sanity—it had become the ability to hold the maximum of impossible combinations in one’s mind.
    Norman Mailer (b. 1923)

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