Talk:F-distribution

message: The second line of TeX on this page is not working.  Why not? Michael Hardy 00:20, 2 Oct 2003 (UTC)
replies: text: There's only one line of TeX on the page. I've tried to fix it but failed; the TeX system here has been tempremental recently, I think... Dysprosia 00:26, 2 Oct 2003 (UTC)
thread_title: Problem with TeX in article

message: I've split out F-statistics into a population genetics article, but I'd like a proper statistician to go over it and explain how they are related :) Dunc|☺ 21:26, 25 Feb 2005 (UTC)
thread_title:  F-statistics 

message: Greetings all,
Recently User:128.135.17.105 removed several external links (Critical F Calculator, Fisher F Calculator  for Hierarchical Multiple Regression, and Fisher F Calculator for Multiple Regression) that I had placed on this page to several F distribution-related online calculators that are available for free on my website. The reason given for this removal by User:128.135.17.105 is that the links are questionable. I would like to hear whether or not this is the majority opinion, as I believe that the free calculators provide a great deal of value to the page. Here's why:
:1. The table of critical F-values linked to from this page (Table of critical values of the F-distribution) is not exhaustive. The free calculator that I propose linking to can compute critical F-values for a much wider range of research needs.
:2. The other external link (Online significance testing with the F-distribution) computes probabilities for F-values, but not critical values of the F-distribution.
:3. There are currently no external links on the page to F-distribution calculators designed for multiple regression and hierarchical multiple regression analyses -- the proposed links would fill this void.
Out of respect for the opinion of User:128.135.17.105, I will not repost the links right away. If anyone agrees that there is value in the external links that User:128.135.17.105 removed, please let the community know by posting your thoughts here. I would particularly enjoy discussing this issue further with User:128.135.17.105, as I believe that (in the spirit of Wikipedia) we can resolve this issue amicably.  :-)
--DanSoper 00:08, 23 June 2006 (UTC)
replies: text: the main discussion is at Talk:Chi-square distribution. Nobody who is logged in has commented yet. 128.135.226.222 00:34, 28 June 2006 (UTC)
thread_title: Questionable external links? Input please

message: Since the kurtosis formula does not fit into the space to the left of the sidebar, a lot of space is left blank immediately before the formula.  Is there a TeX command (e.g. \smfrac, or such) to make the fraction smaller? /*EnumaElish*/  —Preceding unsigned comment added by 66.92.175.254 (talk) 19:13, 7 September 2007 (UTC)
thread_title:  Kurtosis formula and the sidebar together cause a lot of blank space  

message: This article is quite technical, and does not have a simple summary of the concept in plain English. What does it measure? When is it used? What are the strengths/weaknesses? Someone please add these details to make this article more accessible.  —Preceding unsigned comment added by 67.193.142.111 (talk) 19:07, 11 February 2010 (UTC)
replies: text: The article is technical because the mathematics behind the distribution are rather technical.  In its simplest form, the F-distribution arises when we want to compare two independent variances derived from sampling Gaussian populations.  In reality, this application is an artifice: the resulting test and confidence intervals are not distributionally robust.  The real importance of the F-distribution comes from the partition of total variance into variance due to a statistical model and the residual variation.  This application is ubiquitous, but its mathematical justification requires more than passing familiarity with distribution theory and linear algebra.
75.184.34.105 (talk)
Dennis Clason  —Preceding unsigned comment added by 75.184.34.105 (talk) 05:18, 28 December 2010 (UTC)
replies: text: I think the article could benefit from at least a passing lay-accessible discussion of the theory behind the F-distribution, especially in regard to it's common usage in inferential statistics (F-test). Currently, this article is completely useless except to those who already operating a fairly high mathematical proficient and understand the F-distribution to begin with. /my 2 cents  —Preceding unsigned comment added by 137.54.25.125 (talk) 19:46, 7 May 2011 (UTC)
thread_title:  Absence of a lay definition and summary  

message: Is there a reason that external links to F-value calculators are removed from this article? Calculators are provided on the normal, Student's T, and Chi-square distribution pages, and I would think that having a calculator for F-values (as opposed to a table) is even more useful than for other distributions since the tables become *huge* with two degrees of freedom. The last user cited WP:EL, but there is nothing in WP:EL that says anything about the links that were removed. For full disclosure, I made this calculator, but this problem is the exact reason I made it. JokeySmurf (talk) 13:42, 19 September 2010 (UTC)
replies: text: Thanks for pointing those out, I tried to clean them up. Are there others? 018 (talk) 03:50, 20 September 2010 (UTC)
thread_title: No calculators?

message: Fisher's correspondence  (the relevant letters are on pages 319 and 323) makes a couple of things quite clear.  One is that he didn't think Snedecor's naming the variance-ratio distribution F was really intended to honor RAF, except as an afterthought.  The other is that the variance-ratio was not Fisher's preferred solution to the problem.  Fisher preferred to tabulate the log of the variance-ratio distribution (Fisher refers to this as the z-test, which should not be confused with the Gaussian Z-test).
The point is at least somewhat moot now, but given that Fisher cared for neither the honorific nor the testing procedure it seems misleading to cite this distribution as the Snedecor-Fisher distribution.  Snedecor's F seems most accurate in my opinion. 
75.184.34.105 (talk) 05:11, 28 December 2010 (UTC)
thread_title:  Naming the F-distribution 

message: anything wrong with the mean d2/(d2-2)??? when d2 goes to infinity, the F approximate chi square (d1), so the mean should converges to d1, but this mean converges to 1. So something must be wrong. missing d1 in the mean??? 
:sorry my mistake, not F approximate chisquare (d1), but d1*F approximate chi square (d1).
Jackzhp (talk) 16:14, 9 February 2011 (UTC)
thread_title: the mean

message: I have added the formula for the k-th moment. As it is rather simple, there seemed to be no reason not to include it (also in view of the fact that the mgf does not exist). I have added a reference to an on-line source where the formula is proved.  — Preceding unsigned comment added by 2.27.72.102 (talk) 10:30, 25 June 2011 (UTC)
thread_title:  k-th moment 

message: The last comma is missing; the one before "is"
Rrogers314 (talk) 17:23, 23 April 2012 (UTC)
thread_title:  Minor Characteristic function error 

message: :Equivalently, the random variable of the F-distribution may also be written
:
::X = \frac{s_1^2}{\sigma_1^2} \;/\; \frac{s_2^2}{\sigma_2^2}
:
:where s12 and s22 are the sums of squares S12 and S22 from two normal processes with variances σ12 and σ22 divided by the corresponding number of χ2 degrees of freedom, d1 and d2 respectively.
As "the corresponding number of χ2 degrees of freedom, d1 and d2 respectively" do not appear anywhere in the formula X = \frac{s_1^2}{\sigma_1^2} \;/\; \frac{s_2^2}{\sigma_2^2}, it is not clear how to interpret this statement.
--Livingthingdan (talk) 14:33, 1 February 2014 (UTC)
replies: text: s12 = S12 / d1; s22 = S22 / d2.  Jheald (talk) 23:16, 1 February 2014 (UTC)
thread_title:  Inconsistent, or at least confusing, representation in terms of normal variables 

message: Definition have a very long gap, really weird to watch at...--36.225.99.68 (talk) 15:56, 18 December 2015 (UTC)
thread_title:  weird gap 

message: The lead seems to equate ANOVA with F-tests when it says "analysis of variance (ANOVA), e.g., F-test". As I understand it, the two are distinct; ANOVA uses F-tests. Can anyone weigh in to clarify this? Benny White (talk) 15:46, 14 June 2019 (UTC)
thread_title:  Clarification needed in lead—''F''-test ≠ ANOVA 

message: There is a move discussion in progress on Talk:Student's t-distribution which affects this page. Please participate on that page and not in this talk page section. Thank you.  —RMCD bot 04:01, 24 August 2021 (UTC)
thread_title:  Move discussion in progress