# Talk:Score (statistics)

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WikiProject Mathematics (Rated Start-class, Low-importance)
This article is within the scope of WikiProject Mathematics, a collaborative effort to improve the coverage of Mathematics on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.
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Field: Probability and statistics

## Insight

Could someone write a few words on what the significance of the score is?--Adoniscik (talk) 03:21, 10 January 2008 (UTC)

## Statistic?

There is an apparent contradiction between the present article and cited article "Sufficiency (statistics)". The present article says, "Note that V is a function of θ and the observation X. The score V is a sufficient statistic for θ." However, "Sufficiency (statistics)" states, "A quantity T(X) that depends on the (observable) random variable X but not on the (unobservable) parameter θ is called a statistic." This implies that V (being a function of both X and θ) is not a statistic. Thus, it also follows that V cannot be a sufficient statistic for θ. Is there a resolution to this apparent contradiction? PLP Haire 22:13, 4 August 2006 (UTC)

You're right. It's really not clearly explained here. I'll be back soon... Michael Hardy 22:22, 4 August 2006 (UTC)
I agree, you're right. Having calculated a few scores recently, the score is clearly not necessarily a statistic, and so cannot be a sufficient statistic. The sentence ought to be removed (or at least replaced with one saying that if it is a statistic, then it is sufficient if anyone can prove that). — Preceding unsigned comment added by 89.240.198.146 (talk) 17:43, 23 May 2007 (UTC)

You guys are right. I have removed this clearly erroneous statement. --Zvika 08:12, 24 May 2007 (UTC)

## Likelihood maximization?

It seems like the score is the derivative of the cost function for a likelihood maximization, e.g., if you are applying a nonlinear optimization algorithm to find an MLE. Is that right? Should it be said? 71.184.37.150 (talk) 00:57, 8 May 2009 (UTC)

Yes, it is. This is called Fisher scoring. I will add a link. --Zvika (talk) 07:06, 8 May 2009 (UTC)

## Division by zero?

Maybe I'm mising something here but should it be stated what happens if $L(\theta;X)=0$? I assume the score is defined to be zero in such cases? Saraedum (talk) 01:33, 12 July 2009 (UTC)

## Regularity conditions?

Does the property that the expected score is zero hold only under the regularity conditions of the Cramer-Rao bound? —Preceding unsigned comment added by 74.205.127.225 (talk) 05:14, 20 October 2009 (UTC)

I think it requires similar regularity conditions but I don't know if they're exactly the same. --Zvika (talk) 10:58, 20 October 2009 (UTC)

## Bernoulli Example

Can someone please double check the Bernoulli example? In particular the second equality. I feel like it may need additional explanation. Thanks. 82.51.68.234 (talk) 15:58, 20 September 2011 (UTC)