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4 votes
2 answers
138 views

Help developing intuition behind sufficient statistics (Casella & Berger) [duplicate]

Migrated from MSE I am trying to understand the following intuition for sufficient statistics in Casella & Berger (2nd edition, pg. 272): A sufficient statistic captures all of the information ...
Aaron Hendrickson's user avatar
1 vote
0 answers
10 views

Sufficient statistic as iso-surfaces in the distribution density. Is it possible to generalise to multiple parameters?

For continuous distributions, there is a geometric intuition behind sufficient statistics that regards a multivariate probability density as several iso-surfaces. This works at least for cases where a ...
Sextus Empiricus's user avatar
1 vote
0 answers
124 views

Concrete example of what Sufficient Statistics is [closed]

Having read articles to try to understand Sufficient Statistics. Sufficient statistics for layman A sufficient statistic summarizes all the information contained in a sample so that you would make ...
mon's user avatar
  • 1,548
2 votes
0 answers
114 views

What is the space that a class of probability distributions spans when T is a complete sufficient statistic?

There are a few good posts/notes (see here, and here) giving high level geometric intuition of a complete statistic ($E_{T}[g(T); \theta] = 0 \Rightarrow P(g(T)=0; \theta) = 1 \text{ almost everywhere}...
Morris Greenberg's user avatar
0 votes
1 answer
151 views

Understanding the Importance of "Sufficiency" within Statistics

I am trying to better understand what it means to be a "sufficient statistic". "In statistics, a statistic is sufficient with respect to a statistical model and its associated unknown ...
stats_noob's user avatar
4 votes
2 answers
115 views

Understanding sufficient statistics geometrically

Consider the distribution $\mathcal{P} = \mathcal{N}(\mu, 1)$, where the variance is known but the mean is unknown. Let $X_1,X_2\sim P$ i.i.d. In this case $T = X_1+X_2$ is a sufficient statistic. I ...
elexhobby's user avatar
  • 855
10 votes
3 answers
862 views

Sufficient Statistics - Relating the Intuition with the Mathematical Definition

I believe the heuristic definition of a Sufficient Statistic makes sense to me - when you take a sample in order to make an inference about the parameter related to the probability distribution, and ...
user523384's user avatar
5 votes
1 answer
976 views

What is the intuition behind the factorization theorem? (Sufficient statistics)

By the Fisher's factorization theorem, a statistics is a sufficient statistic if (and only if) the joint density, $$ f(x_1, x_2, x_3, \dots x_n; \theta) $$ can be factorized into two functions, $ g(s; ...
WorldGov's user avatar
  • 777
3 votes
2 answers
1k views

Intutitive meaning behind the formal definition of sufficient statistic?

According to the definition of sufficiency, a statistic is sufficient for a parameter if the conditional distribution of $X$ given a value of statistic does not depend upon the parameter. What I am ...
Keshavan Purushothaman's user avatar
14 votes
1 answer
1k views

Intuitive understanding of the Halmos-Savage theorem

The Halmos-Savage theorem says that for a dominated statistical model $(\Omega, \mathscr A, \mathscr P)$ a statistic $T: (\Omega, \mathscr A, \mathscr P)\to(\Omega', \mathscr A')$ is sufficient if (...
Sebastian's user avatar
  • 3,104
4 votes
2 answers
671 views

Sufficient Statistic and Maximum likelihood

This is more a conceptual question, but it seems to me that a sufficient statistic for a parameter is a concepts that applies only if we want to estimate the parameter via maximum likelihood. Is this ...
DanRoDuq's user avatar
  • 586
2 votes
0 answers
289 views

If $T(\bf{X})$ is a sufficient statistic for $\theta$, why does the conditional distribution of $\bf{X}$ given $T(\bf{X})$ doesn't depend on $\theta$? [duplicate]

I know that if $T(\bf{X})$ is a sufficient statistic for $\theta$, then the conditional distribution of $\bf{X}$ given $T(\bf{X})$ doesn't depend on $\theta$. However, I am not sure why this makes ...
user321627's user avatar
  • 4,448
1 vote
0 answers
722 views

Fisher-Neyman factorization theorem, role of $g$

The theorem states that $\tilde Y=T(Y)$ is a sufficient statistic for $X$ iff $p(y|x) = h(y)g(\tilde y | x)$ where $p(y|x)$ is the conditional pdf of $Y$ and $h$ and $g$ are some positive functions. ...
NullCanBeARealCoolValue's user avatar
6 votes
1 answer
2k views

Basic intuition about minimal sufficient statistic

As stated by Wikipedia: A sufficient statistic is minimal sufficient if it can be represented as a function of any other sufficient statistic. In other words, $S(X)$ is minimal sufficient if and ...
Lex's user avatar
  • 269
23 votes
7 answers
3k views

Why does a sufficient statistic contain all the information needed to compute any estimate of the parameter?

I've just started studying statistics and I can't get an intuitive understanding of sufficiency. To be more precise I can't understand how to show that the following two paragraphs are equivalent: ...
gcoll's user avatar
  • 381

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