User talk:Melcombe

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Edit of page on case-control study[edit]

Hello,

Thank you for the edit of my previous edit of the page on case-control studies. My apologies for not respecting the standard layout -I will try to do better in future!

As an epidemiologist however, I feel I must respectfully disagree with certain statements which are now part of this introduction. For instance, the statement that the "retrospective, non-randomized nature [of case-control studies] limits the conclusions that can be drawn from them" is, I feel, not entirely accurate. One aspect which in fact bothered me about the original version of this page was the suggestion that case-control studies are somehow necessarily inferior to cohort studies, as well as the somewhat irrelevant comparison with randomized controlled trials.

It would seem to me that there are two issues which are being confused here. The first being the fact that case-control studies are observational and thus do not constitute the same level of evidence as randomized trials. It does bear noting however that the same could be said of cohort studies. The second issue is the debate concerning the comparison between prospective cohort studies and case-control studies -i.e. which if any is 'better'? My discomfort here mainly concerns this second point: I have met several respected members of my field who do not feel that the case-control study is inferior to a cohort. In fact, depending on the situation and particular research question(s) of interest, the case-control study may even be better. In particular, case-control studies make it much easier to study certain conditions such as cancer, for which it takes a considerable amount of time for a sufficient number of events to accrue and for which cohort studies are frequently underpowered (and this despite many years of follow-up).

If anyone reads the talk pages (the last note dated on the case-control study one dated back from 2008 so I did wonder :) I would post my next edit there prior to integrating it into the actual page. (It just didn't seem to me that anyone was reading it which is why I posted my prior edit directly to the page itself.)Alic D (talk) 21:09, 3 August 2011 (UTC)

Negative Binomial MGF[edit]

Dear Melcombe, I was wondering if you could explain why my modification to the Negative binomial mgf was wrong. I seem to have conflicting views from my university notes, textbooks and the internet. I have an exam tomorrow so would appreciate any explanation. Econstatgeek (talk) 18:05, 1 May 2008 (UTC)

Unfortunately I do not have time to do a full derivation. I have checked the formula in a couple of books. Also there must be a direct correspondence between the mgf and the characteristic function. ONe thing that confuses things is a tendency for different books to use different parameterisations of the negative binomial, so that the same correct formula can look different. Melcombe (talk) 08:42, 2 May 2008 (UTC)

I'll put it down to a difference in notation convention then. Thank you for your reply. Econstatgeek (talk) 16:11, 2 May 2008 (UTC)

Probability and statistics sub-project?[edit]

Dear Melcombe,

I recently proposed starting a "probability and statistics" sub-project (aka task force or work group) of WikiProject Maths and was wondering if you'd be interested in participating. If so, please add your name and any comments at WP:WikiProject Council/Proposals#Probability and statistics. Regards, Qwfp (talk) 22:05, 12 March 2008 (UTC) (PS I believe it's traditional to start a user talk page with some variation on "Welcome to Wikipedia" but as you joined before I did I don't feel I'm in a position to welcome you. The lack of previous comments here would seem to reflect positively on your editing.)

Order statistics[edit]

I noticed that you put an "expert" tag on F-test and I completely agree with that. But I wonder if you can be specific about your concerns about order statistic. Michael Hardy (talk) 19:35, 10 April 2008 (UTC)

OK, I have placed something on article talk page. Melcombe (talk) 08:53, 11 April 2008 (UTC)

Statistical Arbitrage[edit]

In my humble opinion, Statistical arbitrage is more within the scope of something like WP:WikiProject Finance than WP:WikiProject Statistics. It is a topic in Finance (or Mathematical Finance) having some statistical aspects, rather than a mainstream Statistics topic. Encyclops (talk) 17:58, 22 April 2008 (UTC)

See Wikipedia talk:WikiProject Statistics#Things on boundary of scope. My thought was that Statistical arbitrage did involve some statistical thinking in setting up the method. At present WikiProject Statistics is trying to bring all articles on statistics topics into the list of statistical topics to provide a basis for further progress. You might want to look at the project page and consider joining. Melcombe (talk) 18:09, 22 April 2008 (UTC)

Category[edit]

Good idea for creating Category:Meta analysis. However, I do think that it should be spelled "meta-analysis". I have therefore requested a renaming to Category:Meta-analysis on WP:CFD. Please comment on this page. JFW | T@lk 13:12, 30 April 2008 (UTC)

Actuarial science[edit]

Hello. Can you please explain the reason for the change in category? Thanks! -- Avi (talk) 14:38, 6 May 2008 (UTC)

Fair point. Thanks for taking the time to explain. -- Avi (talk) 17:20, 6 May 2008 (UTC)

Estimating Confidence Intervals[edit]

Honorable Melcombe: Is it valid to estimate a confidence interval by multiplying the Student's critical T Value (e.g., +/- 1.96 for a 95% confidence range in a normal population) times the standard deviation of the data range? For example, if the Standard Deviation of the series happens to be 10 and the estimated value is 100, then the 95% confidence range would be from 81.4 (100 - 1.96 x 10) to 119.6 (100 + 1.96 x 10).

If this isn't the appropriate forum to ask this question, please forgive my ignorance and intrusion. Mike. --Grizthedog (talk) 21:50, 13 June 2008 (UTC)

You should really find a better forum for discussing all this. You might try the newgroup called sci.stat.math ... if you don't have a news-reader, it is accessible at http://groups.google.com/group/sci.stat.math/topics .
You need to be more clear about what it is you want to construct. The most usual case is a confidence interval for the mean, in which case your formula would be wrong as you would need to divide the standard deviation of the sample by the square root of the sample size. If you want to find a confidence interval for a further observation from the same population, then your formula in approximately correct ... for modest same sizes you would need to multiply the sample standard deviation by the square root of (1+1/N), where N is the sample size (you might find something about this in the article on "tolerance intervals" ). All this would be making the usual assumptions, but your use of the word "series" might indicate that you have a "time-series" in which there might be serial correlation, in which case the assumptions would not hold. Melcombe (talk) 09:07, 16 June 2008 (UTC)

Re: Lists of basic topics[edit]

I've replied to your post at WP:VPR.

The Transhumanist 19:58, 4 July 2008 (UTC)

RFC at St. Petersburg paradox[edit]

As you have contributed to an earlier related discussion at Talk:St. Petersburg paradox#That d_mn'd period, you may be interested in Talk:St. Petersburg paradox#Request for comments: punctuation after displayed formula.  --Lambiam 18:17, 8 August 2008 (UTC)

K-factor error is now at AfD[edit]

Hello Melcombe. Your prod of K-factor error was contested. See Wikipedia:Articles for deletion/K-factor error. EdJohnston (talk) 00:44, 25 August 2008 (UTC)

Confidence Level / Significance Level[edit]

The latest change is better (though the link doesn't work). However, the article still needs a simple definition of confidence level (i.e. something a layman can understand), and more importantly, an indication that, when used with statistical testing, it should be interpreted as indicating the significance level, preferably with a link to that article. The reason for this is simply the obvious fact that, for the average layman, the reason they would be looking up confidence levels or confidence intervals it that they have seen something in print reporting the results of statistics based research and want to know what the terms mean.

We can do the standard wikipedia "who can hold their breath longest" thing over this, but I'd rather be sensible about it. Perhaps if you changed the article to include these changes in the way you want, we can avoid the baby stuff.

Jim 125.255.16.233 (talk) 12:44, 12 October 2008 (UTC)

Replied on article Talk page. Melcombe (talk) 15:28, 14 October 2008 (UTC)

Central limit theorem[edit]

Please look at Talk:Central_limit_theorem#Asymptotic_normality_for_statistical_estimators. Boris Tsirelson (talk) 19:02, 5 November 2008 (UTC)


Chi square distribution[edit]

Hi Melcome. Thanks for your constructive edit to Chi squared distribution. It beats me why such a well-known fact has attracted such controversy. People (mostly but not exclusively anons) have repeatedly removed the assertion about normality. And it's not vandalism, as they justify their actions on the talk page. Do you have any insight in to why they do this? Me, I'm baffled. Best wishes, Robinh (talk) 20:46, 11 December 2008 (UTC)

Melcombe, wrt. the Pearson's_chi-squared_test definition, if you think notation outranks statistics, how can I argue with you? Muhali (talk) 02:38, 23 February 2012 (UTC)

It certainly does not help clarity if you use the same notation for two different things. Melcombe (talk) 02:58, 23 February 2012 (UTC)
True. So, is it better to use two notations or none?--Muhali (talk) 03:08, 23 February 2012 (UTC)

Note that I reverted most of your changes. Please take a look at the article talk page.--Muhali (talk) 18:12, 23 February 2012 (UTC)

Student's T test[edit]

Thank you, Melcombe, for your edit on the standard deviation estimate not being unbiased. I was concerned about this too and was contemplating a similar edit. However I still have some concerns and would value your opinion. Please see the student's t test talk page for details.

Best wishes, SciberDoc (talk) 22:20, 1 January 2009 (UTC)

Minimum of exponential variables[edit]

Hi. I reverted a change to the exponential distribution article about the minimum of exponential variables, and then noticed that it was your change, and that you are a statistician, and I am not. This prompts me to notify you of my change, in case I am mistaken. I think that you ran afoul of the notation in the article, where the rate \lambda is used in the pdf like this: \lambda e^{-\lambda x}, instead of the alternative definition of e^{-x/\lambda}/\lambda. -- Coffee2theorems (talk) 16:07, 8 January 2009 (UTC)

Cook's distance[edit]

Hi Melcombe, you were the last person improving Cook's distance page. There is still one symbol that I am not sure what exactly it means: Y_{j(i)}. Could you please add its description to the page? Thanks, Alex -- talk 17:40, 17 March 2009 (UTC)

I have added something. Melcombe (talk) 17:52, 17 March 2009 (UTC)
Thanks for both the fix and your remarks to me.Alex -- talk 18:50, 23 March 2009 (UTC)

Citing sources[edit]

I see you've been listing lots of books as references, but in many cases without any specific citations (footnotes); please check out Wikipedia:Citing sources and ask me if you'd like help converting them to something more useful. Dicklyon (talk) 16:30, 27 March 2009 (UTC)

Talk:Arrival theorem[edit]

I've responded to your question on Talk:Arrival theorem and would be interested to hear you views on what you feel the most suitable title is. Whilst random observer property or job observer property both seem suitable to me, arrival theorem and PASTA property (for the Poisson process) seem to be more commonly used, judging by Google Scholar. Gareth Jones (talk) 11:44, 3 June 2009 (UTC)

Characteristic function vs. Moment-generating function[edit]

Hi Melcombe, I wonder if you wouldn't mind if we carry on this discussion to your talk page? Anyways, this is what Lukacs has to say about the subject of mgf (i have his book right now, 2nd ed.):

On p.10 he defines an arbitrary integral transform of an r.v., and gives as an example kernels K_1(t,x)=e^{tx} and K_2(t,x)=t^x which give rise to the moment-generating function and probability-generating function respectively. These two functions are essentially the same, as \text{mgf}(t)=\text{pgf}(e^t). He then remarks

Probability generating functions were introduced by Laplace; we will use these functions only rarely (in section 6.3) and mention them here mainly because they were the first integral transforms systematically used in probability theory.

On p.196 he returns to the subject of mgfs to mention that if f(z) is an analytic characteristic function then M(y) = f(-iy), where y is real. Note that Lukacs never defines mgf for complex or imaginary arguments.

On p.198 he gives an example of a function which has moments of all orders yet doesn't possess an mgf (or an analytic cf).

On p.251 he references a paper by Lévy(1937) where he used mgfs to establish certain convolution properties of Poisson-type distributions.

This is an exhaustive list. My interpretation of this list is that Lukacs doesn't really care much about mgfs, though it would have been a shame not to mention them if only but briefly.


And another question, Melcombe, when you say that "And considering that the major work on characteristic functions defines them for complex t it needs to be included in the main definition." -- could you please give a reference where you have seen such definition? Both Cuppens and Lukacs define it as

If p is probability measure on \mathbb{R}^n, then \hat p is analytic if there exists a function f defined on \mathbb{C}^n with complex values which is regular in some neighborhood of the origin and some constant δ such that

\hat p(t) = f(t) \quad (t\in\mathbb{R}^n,\ \lVert t \rVert < \delta)

and later on they prove that if cf is analytic then it admits a representation

\hat p(z) = \int_{\mathbb{R}^n} e^{i\,(z,u)}p(du) in a convex tube \mathbb{R}^n+i\Gamma

My assessment of this theory is following: the characteristic function is defined only for real-valued arguments, because only then it has all the nice properties such as existence, and boundedness, and it is also much easier to generalize such cf to multi-dimensional rv's. It is also sometimes possible to build an analytic continuation of the cf to a horizontal strip \{-\alpha<\operatorname{Im}(z)<\beta\}, which allows us to derive additional results. However such continuation is only possible if r.v. has infinite number of moments and when the rate of growth of those moments is not too high.

Stpasha (talk) 22:19, 18 June 2009 (UTC)

OK, I have now had a little time to look through what sources I have access to, and they do take the approach of defining the cf for real arguments only, with a later extension to complex values by continuation using analytic functions, which they do say is equivalent to the basic Fourier-type integral for complex arguments (once it is known that the integral exists via the analytical continuation argument). This may be for historical reasons. There may be some way of developing the theory starting from the Fourier-type integral for complex arguments but I haven't found this set down. Nevertheless, because some of the most important results of cf theory are derived via this theory of extension into the complex domain, it seems important in an encyclopedia to note this at an early stage.
As for moment generating functions, it may be that they are unnecessary for theroeticians, the fact is that they are taught at a fairly elementary level of probaility and statistics whereas characteristic functions are not (not least because they involve imaginary numbers). And they are actually used with complex aruments in certain fields of application, where the mgf for some system is derived via theoretical arguments and converted to a density function using numerical inversion based on the inversion formula involving an integral parallel to the imaginary axis. Of course they could do all this using characteristic functions and an intergral along or parallel to the real axis, but they don't. I believe the shift in the axis of integration can help the numerical properties of the integration scheme.
Melcombe (talk) 10:09, 25 June 2009 (UTC)
I saw this only now. MGF and Laplace transforms have advantages for exponential families and especially for maximum-likelihood estimation from such families~(Barndorff Nielsen). More broadly, Laplace transforms preserve positivity and analyticity, while Fourier tranforms and characteristic functions don't.  Kiefer.Wolfowitz  (Discussion) 00:28, 22 February 2011 (UTC)

Optimal design's Introduction: Providing sufficient context for Wikipedia readers?[edit]

I trust that the introduction is improved. Do you have further feedback? ThanksKiefer.Wolfowitz (talk) 13:45, 29 June 2009 (UTC)

Nuisance variables and nuisance parameters[edit]

The split into two different pages I still think is a mistake, so I have raised this at WT:WPSTAT to try to get wider input. Jheald (talk) 17:27, 30 June 2009 (UTC)

Empirical statistical laws[edit]

I have nominated the article for deletion on the grounds stated. Please provide a prominent source per Wikipedia:Verification. I understand the motivation for having an article like this but question it on the grounds of this policy. I'll leave the content in regression to the mean for the moment but the linked article needs to sources for the content to remain. I am assuming good faith, I hope my concerns are clear. Please discuss if not. Cheers. Holon (talk) 12:58, 30 July 2009 (UTC)

"Phenomena"?[edit]

The Cambridge Dictionary includes this: "The term is now generally used to label the phenomena that a variable that is extreme on its first measurement will tend to be closer to the centre of the distribution for a later measurement.

Does it really say "phenomena" instead of "phenomenon"? Michael Hardy (talk) 21:41, 1 August 2009 (UTC)

Statistics outlines[edit]

I noticed you are interested in statistics, and access to statistics articles.

Please take a look at these:

What is your initial impression?

What's missing?

Are they structured well? That is, do they present their respective subjects well?

How can we make them more useful?

For more information, see WP:OOK, WP:OUTLINE, WP:WPOOK.

For examples of well developed outlines on other subjects see Outline of Japan, Outline of Buddhism, Outline of robotics, and Outline of cell biology, and Outline of forestry.

I look forward to your reply.

The Transhumanist 00:32, 16 September 2009 (UTC)

Null hypothesis article[edit]

Your revert of my edits seem to be a bit hasty, not only are you incorrect in your summary later edits incorrectly changed meaning & number was correct as prob was for either 3 heads or three tails which clearly none of my revisions altered (see my diffs), but you have reverted my correction for the probability of 3 heads or tails which is 0.5*0.5*0.5 = 1/8 or an eighth not a quarter. --Zven (talk) 08:46, 24 September 2009 (UTC)

Right I now see what you are getting at, however you also reverted my other edits which probably didn't need to go. --Zven (talk) 08:57, 24 September 2009 (UTC)
Actually, the example is misleading, no wonder there is so much confusion, it states a two headed coin, so three tails is not an outcome at all, only three heads. --Zven (talk) 09:01, 24 September 2009 (UTC)

Dice/Die - Random Variable[edit]

Doh! I knew that! :) Mia Culpa. Cheers. Jwesley78 (talk) 14:25, 22 October 2009 (UTC)

Chi-square distribution vs. Chi distribution.[edit]

You're right. Thanks! Quantling (talk) 17:32, 17 November 2009 (UTC)

Total variation[edit]

Should we have a separate article for the notion of total variation in probability theory and measure theory? I don't like the current arrangement where the material on probability theory has been forked off from the material on measure theory, even though they are essentially the same thing. What seems better to me is to have an article total variation in measure theory and probability theory that deals with both of these notions. Sławomir Biały (talk) 12:15, 9 December 2009 (UTC)

MSWD[edit]

A general technique that is used in statistical methods applied to geochronology.

The mathematics provided deal with general cases, split into the two typical ways MSWD is utlized.

First, to provide a way to analyse the outcome of repeated attempts to measure the same "age", each attempt associated with a known variance (obtained by repeated sampling during the individual attempt. This assumes the sample has a single age.

Second, to provide a way to analyse an isochron, usually defined on a plot of two ratios (e.g. 36Ar/39Ar versus 39Ar/40Ar). —Preceding unsigned comment added by 202.55.153.53 (talk) 09:10, 7 January 2010 (UTC)

Contingency table[edit]

That was a nice edit of the contingency table page. Thanks. Iss246 (talk) 22:36, 11 January 2010 (UTC)

Negative binomial distribution[edit]

Please, before reverting the edit and asserting that I “completely ignored the discussion on the talk page”, make sure you have read that discussion. There was a 1-month old proposal (section Major Changes) to simplify the exposition down to only 1 main definition, and that proposal was met with a (cautious) support.

The main reason why we had 2-column infobox is because readers were frequently confused when they seen apparent discrepancies between the article and their textbooks. Such confusion can be avoided either by bloating the infobox (and actually there are more than 2 possible definitions), or by including a very noticeable alertbox, warning about potential discrepancies when comparing this info to existing textbooks, which is the way we are dealing with the problem right now.  … stpasha »  18:55, 19 January 2010 (UTC)

See User talk:Stpasha for reply. Melcombe (talk) 10:28, 20 January 2010 (UTC)

Sigma algebra too technical?[edit]

Hi Melcombe, please see talk:Sigma-algebra#Too technical?, thanks. Paul August 15:18, 20 January 2010 (UTC)

Just my 2p: the {{context}} template is a lot more self-explanatory (to me at least) for an article where the lede needs to be expanded to explain what the topic is about. — Carl (CBM · talk) 20:20, 20 January 2010 (UTC)

Studentization[edit]

Somehow this mangled sentence found its way into the article:

The consequence of "Studentization" is tcentralhat the complication of treating the probability distribution of the mean,

Can you clarify? Michael Hardy (talk) 23:10, 4 February 2010 (UTC)

Pietro Balesta (economist)[edit]

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Talk:Climate change[edit]

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Experiment Thanks[edit]

Thanks for correcting my spelling, which was surprisingly bad. Thanks also for expanding the bibiographical details of Freedman's Statistics. Best regards, Kiefer.Wolfowitz (talk) 14:33, 12 February 2010 (UTC)

Category on Obsolete statistical procedures[edit]

Melcombe, you purged the category of procedures whose text already named them as obsolete. I don't understand your comment that categories shouldn't have just one item, given your purging behavior of Box-Pierce (whose text described it as obsolete) and the F-test. Kiefer.Wolfowitz (talk) 20:13, 8 March 2010 (UTC)

Hi[edit]

Hi there. Thanks for the post. It seems that everything here is done by editing a page. I hope this is the right way to "reply" a message. I didn't see any post on the discussion page about LAD, only those links to the stats groups, so there I went! Thanks for the pointers, I will write this down later.

Best,

--Gpfreitas (talk) 13:13, 9 March 2010 (UTC)

Is there a stats ER list somewhere?[edit]

Hi, I saw that you edit stats pages. Is there an ambulance/ER type list for articles in real trouble, e.g. Random sequence is in bad shape, Statistical randomness is barely ok, but has errors, and both are almost reference free. Applications of randomness probably wins the worst article award and Randomness is no gem either. Is there a "help needed" list somewhere? Thanks. History2007 (talk) 13:30, 10 March 2010 (UTC)

Thanks, I think I will just add the templates on the pages. These pages are not my priority, I was just amazed how low quality they all are - compared with info on Paris Hilton that gets great attention in Wikipedia. Thanks. History2007 (talk) 16:35, 10 March 2010 (UTC)

Complete Spatial Randomness[edit]

Dear Melcombe,

I was wondering if you have a reference for the derivation of the probability of locating the N^{th} nearest neighbor at some radial distance r, shown at the Complete spatial randomness page? A more detail outline of the derivation would be greatly appreciated.

Thank you very much,

Bsesar (talk) 21:46, 8 April 2010 (UTC)

Best regards[edit]

Dear Melcombe, I trust that you are in good health and spirits. I have been a fan of your editing for a long time. I am sorry for my part in sometimes contentious editing on "statistical inference", but I think that the resulting article was improved, certainly over my rather crude initial contributions. Sincerely, Kiefer.Wolfowitz (talk) 22:36, 14 April 2010 (UTC)

Rice distribution: The Koay inversion technique[edit]

Dear Melcombe,

The Koay inversion technique is indeed a parameter estimation if viewed from a statistical point of view but it is also an inversion technique when viewed from the "inverse problems" point of view. Of course, there are other estimation techniques but as an inversion technique the Koay inversion technique is very original and peculiar at the same time. As far as I can tell, I have not seen anything like this before. Your comment on the technique would be a welcome addition to the Wikipedia. Therefore, I think a more specific name for this inversion technique is not at all inappropriate.

-Carl —Preceding unsigned comment added by StanfordCommSci (talkcontribs) 16:52, 14 May 2010 (UTC)

Statistics education and Making Mathematics Count (Smith inquiry)[edit]

Hi Melcombe! I updated the references and modified some statements in the article statistics education. Perhaps you could add something to the stub Making Mathematics Count, about the report of Adrian Smith (academic). Thanks, Kiefer.Wolfowitz (talk) 13:12, 15 May 2010 (UTC)

Statistical Hypothesis Testing[edit]

Hello, I'm still not sure why you think a composite null hypothesis is ok. You can't compute the probability of a type I error if your null hypothesis is composite. I have gone into greater detail on the Statistical Hypothesis Testing talk page.

Tank (talk) 09:55, 19 May 2010 (UTC)

Statistics Template[edit]

Hello Melcombe! I appreciate your retaining the mean-unbiased and median-unbiased estimators in your latest edits (which only partially reverted mine). Could you (briefly) explain why you keep removing "questionaire" and "survey" from social statistics? (IMHO, surveys are intrinsically human-subjects statistics.) Also, I am sincerly puzzled by your repeated comment about the equality of sampling and experiments: Please explain a bit! Thanks, and best regards, Kiefer.Wolfowitz (talk) 19:16, 25 May 2010 (UTC)

Sawilowsky's Paradox[edit]

Hi Melcombe - Thanks for questioning the validity of references at that article. Actually, the 2003 article does not use the term, either. It's easy to check because it is a free journal. Apparently, the term is introduced by the 2010 reference. And not only is that not independent, it is not verifiable, because the Publisher's website says it won't be released until August 30. Nor is it peer-reviewed. But I'm not sure whether this is a case for AfD or speedy, that's up to you.

Also: watch out for possible sockpuppets, like 76.112.241.229. Best regards, Iulus Ascanius (talk) 19:47, 1 June 2010 (UTC)

I have marked you as a reviewer[edit]

I have added the "reviewers" property to your user account. This property is related to the Pending changes system that is currently being tried. This system loosens page protection by allowing anonymous users to make "pending" changes which don't become "live" until they're "reviewed". However, logged-in users always see the very latest version of each page with no delay. A good explanation of the system is given in this image. The system is only being used for pages that would otherwise be protected from editing.

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To use the system, you can simply edit the page as you normally would, but you should also mark the latest revision as "reviewed" if you have looked at it to ensure it isn't problematic. Edits should generally be accepted if you wouldn't undo them in normal editing: they don't have obvious vandalism, personal attacks, etc. If an edit is problematic, you can fix it by editing or undoing it, just like normal. You are permitted to mark your own changes as reviewed.

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Correlation[edit]

Melcombe,

You deleted my link to modecube.com saying that the link was of no use -which is rather a harsh statment-.

Please note that the first editor, Debivort, said it wasn't a clear call.

Then, people who don't have a PhD in statistics may have some legit questions such as where the covariance formula comes from, why the variance is derived from the covariance etc.

So, if:

  • those question are indeed questions some people might have,
  • there are no simple answers to that in the article and the existing links,
  • the explanations in modecube.com make sense,

then I dont see why the link is of no use.

I may be wrong, I just would like to understand why (my goal is just to help as many people as I think those explanations would have helped me so much when I was a student)

Regards, Philippe 86.183.200.206 (talk) 13:33, 23 June 2010 (UTC)

Dear Melcombe,

Thanks you for your welcolme, your useful links and your answer.

My understanding of the later is that my points are valid (questions one can ask, answers not in article, answers in the external website) but that the explanations look like textbook, they are "how to" (calculate) material, and thus should not belong to Wikipedia but rather to some Wiki etc.

I can understand that, even if I would advocate that Wikipedia could give some further explanations/example when a subject is complex. For example, an article that helped me a lot when studying for the CFA exam is http://en.wikipedia.org/wiki/Bond_duration. And this article displays a short proof/explanation for the modififed duration.

What's more, I do believe that, even if Wikipedia should keep to an introductional level, it still could/should offer some further reading leads. As a case in point, programming articles usually provides in depth examples and links to detailed implementations (http://en.wikipedia.org/wiki/Factory_method_pattern etc.)

Best Regards, Philippe Vergnetp (talk) 08:40, 24 June 2010 (UTC)

Quantitative research and experiment[edit]

Anova treatments are typically nominal. A Bernoulli response is often nominal. It is fallacious to say that experiments are quantitative, although this fallacy has been common in the lower regions of some social-science disciplines, particularly under the influence of 19th Century German fallacies. Please reconsider your adding "quantitative research" as a category for experiments.

It would be appropriate to put experiments under "mathematical methods" or "statistical methods", which are wider categories than "quantitative methods". Bets regards , Kiefer.Wolfowitz (talk) 15:06, 10 July 2010 (UTC)

V-Optimal Histograms[edit]

Respected Melcombe,

I have looked at the description given for V-Optimal Histograms, Could you kindly elaborate how the weighted variance is calculated in the examples. It's formula is given as W = sum(nj, Vj). But using this formula I am not able to get the weighted variance of 2.28 for the given data. Please clarify it as soon as possible.

Thanks, Nagesh Bhattu,PhD Student —Preceding unsigned comment added by 220.225.248.2 (talk) 13:17, 15 July 2010 (UTC)

I don't know. I merely copied a formula from one of the papers that were cited but which no longer seem to be available online. There may a problem with know which version of variance to use (divided by N or N-1). You might try contacting the oroginal author of the article. Melcombe (talk) 15:29, 15 July 2010 (UTC)

John C. Gittins[edit]

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Total probability[edit]

Hi, why did you revert my changes? What is the definition of E_B and Pr(A|B) where B is a random variable? B must be an event, or in general a sigma-algebra, not a random variable. —Preceding unsigned comment added by 121.102.42.138 (talk) 13:29, 10 September 2010 (UTC)

You said ... You said ... Hi, why did you revert my changes? What is the definition of E_B and Pr(A|B) where B is a random variable? B must be an event, or in general a sigma-algebra, not a random variable. —Preceding unsigned comment added by 121.102.42.138 (talk) 13:29, 10 September 2010 (UTC)

       The line immediately above defined B as a random variable. I will change it back to X to avoid more confusion. But introducing =n here was wrong because n has a different meaning later, and the quantity condioned on has to be a random variable, otherwise the expectation can'y be taken. Melcombe (talk) 13:53, 10 September 2010 (UTC)

Uhm... it is also true that Pr(A|X) is not defined if X is a random variable. It needs to be an event or (more generally) a sigma-algebra - in this case a sigma algebra generated by X. —Preceding unsigned comment added by 121.102.42.138 (talk) 14:31, 10 September 2010 (UTC)

Thank you![edit]

Hello Melcombe. As a newbie, I'd like to thank you for helping out in cleaning up the Multifactor Design of Experiments Software article. If you have more suggestions, I'd be most welcome to follow your advice. Again, thanks! Agatecat2700 09:35, 13 September 2010 (UTC) —Preceding unsigned comment added by Agatecat2700 (talkcontribs)

Thanks[edit]

Thank you for tidying up Category:Monte Carlo methods by creating Category:Monte Carlo methodologists. Fintor (talk) 10:48, 14 September 2010 (UTC)

Proposed deletion of E-net (metric spaces)[edit]

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The article E-net (metric spaces) has been proposed for deletion because of the following concern:

Doesn't seem to provide any more than a dictionary definition, albeit a technical one. WP:NOTDICT.

While all contributions to Wikipedia are appreciated, content or articles may be deleted for any of several reasons.

You may prevent the proposed deletion by removing the {{dated prod}} notice, but please explain why in your edit summary or on the article's talk page.

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Statistical hypothesis testing[edit]

Could you please have a look at the changes Joe The-tenth-zdog made in the article statistical hypothesis testing. There are errors in them, inconsistencies, a strange way of introducing and superfluous tables. Nijdam (talk) 14:09, 23 September 2010 (UTC)

Thanks for interfering. Nijdam (talk) 22:27, 23 September 2010 (UTC)

Law of total expectation[edit]

Just thought I'd drop you a line that I undid your recent correction. I think the original time series formulation was correct and I added a reference supporting it. The original way also conforms better with the preceding equation. Do you want to add an additional formulation? --Bequw (talk) 05:07, 29 September 2010 (UTC)

Significance (journal)[edit]

Hello, how do you do? I also work in statistics (kind of) in the UK. Many thanks for the Significance page. I just overwrote a recent correction you made as I feared it could sound a little advertise-y..what do you think? Also, how could I change the title from 'journal' to 'magazine'? As you're the initial author of the piece would it be you who could change this or must I contact an editor? Thank you. Abdelhk (talk) 05 November 2010 15:11 (UTC)

Nassim Nicholas Taleb[edit]

I made a few edits to Nassim Nicholas Taleb and tagged it. I noticed your remarks on the closed AfD merge discussion and wonder if you'd be interested in working on the article to bring it up to GA or at least not a collection of fan club effusions. I've already gotten some push-back from one of the keepers of the flame, and it's something I woouldn't want to try to do alone. Tom Reedy (talk) 13:36, 9 December 2010 (UTC)

Poisson Binomial Distribution[edit]

Hi Dr. Melcombe,

I recently have come across the "Poisson Binomial Distribution", which turns out to be something that greatly helps with a statistical problem I am currently dealing with. I know for a fact that a number of statistics textbooks do not have this distribution listed and Google does not really return hits that describe this distribution. When I showed the distribution to a few colleagues in the Math Department, they claimed they've never seen this distribution before as well (and they are pretty smart individuals). Since I am not a statistician myself, I don't exactly know how well-known this distribution is. Given that a paper about it was published in 1993 by Wang, I'd presume there would've been 17 years for statisticians to absorb this distribution into the fold. Do you think you can tell me how often this distribution is used in practice and whether or not it is accepted by the statistics community? If it is relatively obscure, then I might have to spend a bit of time to check over the math just to make sure I am not using something that's wrong (although on the surface, the pdf and mean equations look reasonable).

Thanks. Bobthefish2 (talk) 08:04, 20 December 2010 (UTC)

There may be some confusion here. The prime source I have uses "Poisson Binomial Distribution" for a different distribution than that set out in Poisson binomial distribution. However, it does have that distribution under the name "Poissonian binomial sampling", but does say that has been known also under that "Poisson Binomial Distribution" and as the "binomial distribution of Poisson". References go back to Poisson in 1837. My source is: Johnson NL; Kotz, S.; Kemp, A.W.(1993) Univariate Discrete Distributions, 2nd edition. Wiley ISBN 0-471-54897-9 (page138 for "Poissonian binomial sampling"). I think that perhaps this hasn't been generally counted as a "distribution" because it has so many parameters, but it has certainly been studied. Melcombe (talk) 10:00, 21 December 2010 (UTC) (Placed on user's talk page also) Melcombe (talk) 10:03, 21 December 2010 (UTC)

Mathematical Reviews template[edit]

Dear Melcombe,

You have repeatedly removed the Mathematical Reviews template from (my) citations. Would you please cease removing this information, or argue against this template at the its talk page (with a notice at the Mathematics Project)?

Many readers of mathematical articles are at universities or institutes with subscriptions to Mathematical Reviews, and these readers benefit from the links. I know that I do! Even when a book or an article has been merely listed without a review, the Mathematical Reviews database provides helpful links to publisher, other articles by the author, forward citations to other references (sometimes later editions with reviews), and sometimes backwards citations, all of which are helpful.

(I have tried to improve my citation practice, following your suggestions. Please see my best efforts at the article on the Shapley-Folkman lemma, which is under good article review, and which would benefit from your scrutiny.)

Sincerely, Kiefer.Wolfowitz (talk) 11:49, 21 December 2010 (UTC)

Harvard citation templates[edit]

Dear Melcombe,

You might like the harvard citation templates that are used in the Shapley-Folkman lemma article. They allow page referencing with links to the original citation information.

Best regards, Kiefer.Wolfowitz (talk) 22:33, 19 January 2011 (UTC)

Thanks for tidying up DoE[edit]

Hi Melcombe,

I appreciate your updating the citations on DoE, particularly after you have expressed concern that I should consider whether Peirce needs to be cited so much (if my memory is correct). Your updating the Peirce citations is another sign of your good character!

Best regards,  Kiefer.Wolfowitz  (Discussion) 14:53, 15 March 2011 (UTC)

Categories[edit]

Hi, I wondered if you could explain your reasoning in changing categories for example in V-statistic. You changed Category:Statistics + Category:Probability + Category:Theory of probability distributions to just Category:Estimation theory.

I don't think that Estimation theory adequately covers the scope of V-statistis as they are not used just for estimation. In fact, in the many examples involving degenerate kernels typically the statistic is used for hypothesis testing and does not have a good application for estimation (e.g. Cramer-von Mises type statistics, and others). I could give more examples. Also I don't understand why general categories such as Statistics or Probability should be deleted. V-statistics encompass a wide class of statistics, so I thought category Statistics is applicable. But then I noticed that you called it a "silly" category for U-statistics. Perhaps I do not understand the rationale of a category. In biographies all categories that apply are used, even if one or more is a superset of the other. Why is it different here? When I pull up a page of categories on say Theory of probability distributions, I would hope that I can find most relevant articles and not just the ones that failed to fall into a more specific category. Have I missed the point? A good explanation would help me. Mathstat (talk) 20:20, 22 February 2011 (UTC)

Hi, thanks for your reply. Maybe the real problem is that there is not a broad enough yet narrow enough category for some articles. I replied more on my talk page below your explanation. Mathstat (talk) 17:48, 25 February 2011 (UTC)

Probabilities which are the reverse of each other[edit]

Probabilities which are one another's reverse is meaningless, I think. Bayes theorem is about updating of beliefs given new evidence. Please explain what you think was wrong in my edit. Richard Gill (talk) 21:01, 3 March 2011 (UTC)

I have made another attempt at improvement. Richard Gill (talk) 09:33, 4 March 2011 (UTC)

Mean squared error, etc.[edit]

Hi, Melcombe, thanks for redoing mean square error as mean squared error. Probably this has already occurred to you, but I hope you can do the same thing with Root mean square deviation. Duoduoduo (talk) 18:11, 16 March 2011 (UTC)

Georges Romme[edit]

Hi, I wikified the whole article, and considered the fact that this is about a respectable Dutch professor. I don't think there is a need to restore those tags unless the original editor starts making mayor changes again. -- Mdd (talk) 19:14, 22 March 2011 (UTC)

Talk:Completeness_(statistics)[edit]

please check Talk:Completeness_(statistics). I mean would you please provide an example that a complete statistic is not sufficient. We know sufficiency does not imply completeness, but can you provide an example that a minimal sufficient statistic which is not complete. So in total 2 examples. Jackzhp (talk) 15:06, 25 March 2011 (UTC)

Copulas[edit]

Hi Melcombe. As you are one of the most active wiki-mathematicians and you once made some edits to the article Copula (statistics), I would like to ask you about something. I would like to develop and improve the latter article. Started with that on sunday, but got completely reverted by some guy who calls probability theory a small subset of statistics... I dont want to start an edit war. could you have a look at my edits and comment? or even better, if you have some time free, help editing? that would be great! I dont insist on the renaming, but the content revertions i do not understand. regards, Philtime (talk) 19:05, 17 May 2011 (UTC)

Hi melcombe, thank you very much for your constructive comments. I'll work over my edits in the near future according to the stated manual. Philtime (talk) 16:41, 21 May 2011 (UTC)

Undeletion following AfD[edit]

An article you deleted following an AfD has been restored (not by me). Is it possible that you could restore the old version of the Talk page. The detail for the Talk page seems to be:

  • 12:56, 11 June 2009 Stifle (talk | contribs) deleted "Talk:Lukaszyk-Karmowski metric" ‎ (Wikipedia:Articles for deletion/Lukaszyk-Karmowski metric)

This is probably not very important but it might be helpful to have the old discussion. Melcombe (talk) 16:03, 18 May 2011 (UTC)

Done, although in future you will find you will get requests like this completed more quickly at WP:REFUND. Stifle (talk) 09:13, 19 May 2011 (UTC)

Orphaned article[edit]

Hi Melcombe. Thank you very much for your edits - most helpful. There are now at least 3 links pointing to SABRE Research UK. How does the page get deorphaned? SBGREEN. P.S. I am very new to Wiki and any help or advice most welcome. —Preceding undated comment added 15:07, 2 June 2011 (UTC). PPS. Sorry forgot tilde thing - will add now. SBGREEN (talk) 15:16, 2 June 2011 (UTC)

Elementary event[edit]

Alright I saw you reinsert tags and added a few new ones. So what exactly is the problem? I don't quite see we need inline references for an article that at best 1/3 of page unless there is something controversial in there. If that's the case however it should be pointed out on the discussion page.--Kmhkmh (talk) 17:29, 9 June 2011 (UTC)

Hyphens[edit]

It's best not omit the hyphens that cue the reader to the structure of a phrase, in an encyclopedia that's intended to be as clear as possible, so could you fix your new categories, in which the compound nouns time domain and frequency domain are used without hyphens as adjectives modifying analysis? Dicklyon (talk) 14:24, 16 June 2011 (UTC)

Derivation of Dirichlet distribution from gamma distributed variables[edit]

Dear Melcombe,

I just wanted to ask you whether you can explain to me what has happened to the Jacobian during the derivation of the dirichlet distribution from gamma distributed variables (in the proof you have removed in the article 'Dirichlet ditribution')? I think it's more or less the same proof as in Luc Devroyes book referenced in that article, but I don't understand this one either.

Much thanks in advance — Preceding unsigned comment added by Tuonawa (talkcontribs) 11:43, 17 June 2011 (UTC)

Convolution of probability distributions[edit]

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Proposed deletion of Confidence in statistical conclusions[edit]

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The article Confidence in statistical conclusions has been proposed for deletion because of the following concern:

No sources, OR, reads like an essay

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Reduction in categories[edit]

Melcolme, thanks for cleaning up the categories on Marketing science . (I'm a newbie when it comes to new Wikipedia articles). I inherited the categories from Operations research , from which Marketing science has a heritage, so I don't appreciate whether the categories (e.g. Applied mathematics) apply or not. Marketing science without mathematics (wouldn't be much of a science). Daviding (talk) 15:04, 5 July 2011 (UTC)

Progressively measurable processes[edit]

Melcolme, I disagree with your reversion of an edit of mine. The lead that you have reverted to is simply incorrect. Progressively measurable processes can "see into the future": case point: deterministic processes can be progressively measurable. I'm not aware of any intuitive definition of it. The most that can be said is that it is a property that certain stochastic processes have. RobertHannah89 (talk) 10:15, 5 August 2011 (UTC)

Right, but let's just be clear, you're reverting an edit because the FALSE information met the understandability criterion. I have asked lecturers and I have trawled the internet and I cannot find an intuitive definition of progressively measurable. It is better to have a correct but difficult definition than a completely false one. Would you please undo your reversion?RobertHannah89 (talk) 00:52, 11 August 2011 (UTC)

\Pr[edit]

Please notice my recent edit to stochastic equicontinuity. \Pr is a standard operatorname, and on some browsers looks different from \text{Pr}. Michael Hardy (talk) 11:17, 17 August 2011 (UTC)

clarifying things[edit]

You wrote:

Let  \{ H_n(\theta): n \geq 1 \} be a family of functions defined from \Theta \rightarrow \reals, where \Theta is any normed metric space. Here \{ H_n(\theta) \} might represent a sequence of estimators applied to datasets of size n given that the data arises from a population for which the parameter indexing the statistical model for the data is θ. Then \{ H_n \} is stochastically equicontinuous if, for every  \epsilon > 0, there is a \delta > 0 such that:

 \lim_{n \rightarrow \infty} \Pr\left( \sup_{\theta \in \Theta} \sup_{\theta' \in B(\theta, \delta)} |H_n(\theta') - H_n(\theta)| > \epsilon \right) < \delta .

Here B(θ, δ) represents a ball in the parameter space, centred at θ and whose radius depends on δ.

What exactly do you mean by the term "normed metric space"? Do you mean a normed vector space? Or maybe just a metric space?

How can a family of functions from the parameter space to the reals "represent a sequence of estimators"? Generally an estimator depends on data and not on the parameter, since an estimator is observable and a parameter being estimated is not.

Later you write of the probability that Hn(θ) differs from Hn(θ') by more than a certain amount. That seems to presuppose that Hn(θ) does not simply depend on θ, but also depends on the data, so it has a random component. That being the case, it seems misleading to say earlier in the paragraph simply that Hn is a function from the parameter space into the reals. Michael Hardy (talk) 11:52, 17 August 2011 (UTC)

The text here was mainly copied from article equicontinuity, and the problems originated there. Melcombe (talk) 08:29, 18 August 2011 (UTC)
There are generalizations of absolutely homogeneous norms (B* norms or for complete spaces B norms) to Frechet spaces and more generally to metric linear spaces, where they are called F* norms (or F-norms for complete spaces). (More generally, there are modular spaces, etc.) Kibbitzingly,  Kiefer.Wolfowitz 16:49, 16 September 2011 (UTC)

Economic methodology[edit]

Surprising how much more balanced that little-to-start-with article looks with the "Scope" heading. --Thomasmeeks (talk) 18:08, 20 August 2011 (UTC)

Hi Melcombe, A few days ago I noticed this entry on your talk page and decided to take a look at economic methodology. I found a page with great sources but no content. I decided to make it into a bibliography, which is what it really was. However, now I find myself in need of guidance as to how to jump start a real article for this topic, and reformat the old article as a bibliography. This is an important field, which overlaps with statistics quite a bit, but as most economists, I do not know much about it. Any suggestion would be appreciated. Yaniv256 (talk) 19:55, 28 July 2012 (UTC)

http://en.wikipedia.org/wiki/Haplogroup_J1_(Y-DNA)[edit]

Please review the map, the work of Tofanelli et al, Hassan et al, and comment in the discussions:

http://en.wikipedia.org/wiki/File:HG_J1_(ADN-Y)
http://hpgl.stanford.edu/publications/AJHG_2004_v74_p1023-1034.pdf http://ychrom.invint.net/upload/iblock/94d/Hassan%202008%20Y-Chromosome%20Variation%20Among%20Sudanese.pdf
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC384897/figure/FG1/ http://en.wikipedia.org/wiki/Haplogroup_J1_(Y-DNA)
http://en.wikipedia.org/wiki/Talk:Haplogroup_J1_(Y-DNA)
Essentially, the issue is whether J1 dominates in Sudan and the Caucasus at over 60%. John Lloyd Scharf 10:18, 23 August 2011 (UTC)

Bayesian inference[edit]

Hi Melcombe. You inserted a OR warning in the article, and I commented on the discussion page, but you did not respond for several months, and so I removed the OR warning. Now you reinserted it. Why not use the discussion page? Do you need further proof? Bo Jacoby (talk) 22:01, 15 September 2011 (UTC).

Melcombe. While still not using the discussion page you remove useful subsections. That is plain vandalism on your part. Bo Jacoby (talk) 23:44, 20 February 2012 (UTC).

This is of course nonsense. The material is plainly WP:OR as no WP:Reliable sources have been included. It also fails the test of being important to the description of Bayesian inference in general terms, and serves only to get in the way of expansion in useful directions. Moreover, it fails any reasonable excuse for being included as a "proof" of a result such as outlined as possibilities in WP:MOSMATH. Applying the rules of Wikipedia standards is clearly not vandalism. If this stuff were "useful" someone could provide a source for it and it might then be sensible to construct an article specific to Bayesian inference for that specific distribution, in which this stuff could be included. Melcombe (talk) 22:40, 22 February 2012 (UTC)

Thank you for answering after 5 months. I will comment on Bayesian inference#Deletion of unnecessary maths portions. Bo Jacoby (talk) 03:51, 23 February 2012 (UTC).

Sampling (statistics) and template:Social surveys[edit]

Hi Melcombe!

Thanks for your help with the article.

(I did everything from memory, so there is some chance of minor mismatches between content in our article and the citation to Lohr or the 3 Swedes, which to me is tolerable.... As you have reminded me before, page references are preferable, but my time is limited ....)

You might wish to look at the template on social surveys, template:Social surveys, which I've tried to upgrade.

Best regards,  Kiefer.Wolfowitz 16:45, 16 September 2011 (UTC)

Spectral risk measure[edit]

I noticed you put the notability tag on spectral risk measure. I have decided over the next few days to try to improve that page to the best of my ability (since I am currently working on my PhD with research on risk measures). I was wondering if you can remember what about that topic made you think it was non-notable. Thank you. Zfeinst (talk) 04:57, 12 October 2011 (UTC)

Thank you for your comments, I believe I have dealt with them (at a minimum at least) and have removed the notability tag. If you have any other comments I would appreciate it, but you have helped a lot already, thank you.Zfeinst (talk) 17:59, 14 October 2011 (UTC)

Multivariate Normal[edit]

Hi could you revert the changes back for now? It was my intention to change the text to follow "Zero's" copy further down, through the part about definitions, and maybe add my paragraph only as a clarification somewhere further down. I'm pretty new to this, sorry if I'm not putting my comments in the right place. Marc.coram (talk) 10:45, 28 October 2011 (UTC) Oh I see, kinda, you put that material into "other representations". Hmmm. But those are the *real* definitions. Bother, I'm too tired to figure this out right now. I'll return to the MVN chat page tomorrow, and try to draft a fix /discuss it there. Marc.coram (talk) 11:00, 28 October 2011 (UTC) Hi Melcombe. I made some edits last Friday. Seem ok? Thanks for your help. — Preceding unsigned comment added by Marc.coram (talkcontribs) 06:05, 31 October 2011 (UTC)

M/G/1 queue or M/G/1 model[edit]

Thanks for your recent contributions to the M/G/1 queue article. Particularly in the definition section I feel you've significantly improved readability. I'm less certain about renaming the page though. Google scholar suggests M/G/1 queue being a much more common name for the model. I was tempted to move the M/M/1 model article to M/M/1 queue. Was your rename based just on the existing M/M/1 articles? Gareth Jones (talk) 14:49, 1 November 2011 (UTC)

Yes, this was based on the existing M/M/1 and M/M/c articles. However, I slightly prefer the M/G/1 queue type of name, so why not go ahead and rename all 3 to that style. Melcombe (talk) 17:53, 1 November 2011 (UTC)

Also, I've corrected your clarification request about the queue length distribution. Gareth Jones (talk) 17:28, 1 November 2011 (UTC)

Statistical proof[edit]

Hi there. You might like to check what is happening to Statistical proof since you've been there before! Tayste (edits) 01:41, 11 November 2011 (UTC)

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comment - R programming language[edit]

Dear Sir,

Although indeed all the bugs should be reported to R's developers, I think that these bugs also SHOULD be put in Wikipedia, because a) this is known and reproducible and b) is something of intellectual value. I disagree that Wikipedia should consist of flashy ads for buggy software. Please do not exclude this material. — Preceding unsigned comment added by 75.150.66.10 (talk) 17:46, 10 January 2012 (UTC)

The template "{{dice}}"[edit]

Hi Melcombe. I see that you have reverted two of my edits, eliminating the use of the template "{{dice}}". I'd like to understand your reasoning for these reverts. I have several concerns with regard to the use of this template: It is confusing to find "{{dice}}" instead of the natural "die" when the singular is wanted, it generates a link, which can result in violations of WP:OVERLINK, it will encourage, it seems to me, the very ignorance that is the root of the problem, and finally I don't see how it, in any way, avoids the problem of editors changing "die" to "dice" inappropriately. Regards, Paul August 15:28, 11 January 2012 (UTC)

Exponentially modified Gaussian distribution[edit]

I see you're improving the EMG distribution page (http://en.wikipedia.org/wiki/Exponentially_modified_Gaussian_distribution). I noticed there is another page of similar content, should it be changed to a redirect? http://en.wikipedia.org/wiki/Exponentially_Modified_Gaussian Shawn@garbett.org (talk) 21:42, 23 January 2012 (UTC)

A redirect would be good, but it may be worth saving the figure which shows the "chromatography" notation. I notice that you had a comment about characteristic functions having been removed ... I haven't seen where these were, but it would be good to have a formula for the characteristic function. Melcombe (talk) 21:54, 23 January 2012 (UTC)

I think the characteristic function is in one of the earliest references. I can add that. I'll can do the redirect if you don't beat me to it. Shawn@garbett.org (talk) 21:58, 23 January 2012 (UTC)

I have merged the material from the page I created with this one. The estimators of the parameters should be useful for users of this distribution. DrMicro (talk) 19:18, 24 January 2012 (UTC)

I had posed a question here. Please ignore what I wrote earlier. I was in error.DrMicro (talk) 23:13, 24 January 2012 (UTC)

Odds and ends[edit]

First thank you for your help on the articles I have been working on.

Second a question

You edited the sample variances for the kurtosis and skewness. Normally these statistics are used to test for departures from normality.

for example [[1]]

For that reason are the comments regarding normality required or are they possibly redundant? This is potentially a tricky technical issue and I would value your opinion on it. Thank you in advance. DrMicro (talk) 17:57, 26 January 2012 (UTC)

Thanks you for your note. This was an issue I was not completely clear on.DrMicro (talk) 20:03, 26 January 2012 (UTC)

Citation needed[edit]

Can you explain why you replaced the 'citation needed' flag in standard deviation? I think it is nonsense to put citations to every easily provable fact that can be checked in many different standard textbooks. What is then, according to you, the wikipedia standard? Why is a citation needed for this mathematical fact and not for all the other mathematical facts, formulae, etc. in this article. Or do you think that those should be tagged also. By the way, what do you think how it looks to the reader? It looks as if there is doubt about these facts, which is absolutely nonsense. KKoolstra (talk) 20:16, 28 January 2012 (UTC)

Citation Claim on Absorbing Markov Chain[edit]

Hi, I would like to discuss your recent edit to the Absorbing Markov chain article on its talk page. If you could respond to my question there, that would be great. Thanks :) Bender2k14 (talk) 21:46, 28 January 2012 (UTC)

Hello again. Do you have another response for me on the talk page? Bender2k14 (talk) 13:00, 19 March 2012 (UTC)

ODDS external site[edit]

Hello Melcombe,

Few days ago I place a link at http://en.wikipedia.org/wiki/Odds which was heading to http://www.oddsarchive.com That site is quite unique (provides all sports odds in graphical mode for past and future events) and has no hide advertising or affiliation system included.

I would like to ask you why did not let it there ?

Thank you, Marcel — Preceding unsigned comment added by Psiaii (talkcontribs) 08:37, 1 February 2012 (UTC)

I see it as an advert for the betting industry in general. It seems out of context in the Odds article and fails WP:EL there. You might try placing the link in Sports betting, which at least has the same context. Melcombe (talk) 09:22, 1 February 2012 (UTC)

Categories[edit]

Hello Melcombe,

you attributed to me an opinion which I do not hold. If you ask me whether I agree with all the edits of Brad7777, the answer is probably negative. However, I also do not think they are blatantly inappropriate. There is nothing inherently wrong with changing the category structure, and the word "consensus" is abused in the discussion (or so it seems to me).

I do not retract my statement that you cited, and I think it applies to your comment as well. In this thread, only the comments of Tkuvho and David Eppstein contributed to constructive discussion.

Best regards, Sasha (talk) 22:23, 5 February 2012 (UTC)

You said (....)
The constructive criticism is that the destructive activity of wholesale arbitrary restructuring of categories should stop. User:Melcombe
Thanks for your reply. I moved the discussion here (to make it easier to follow, please correct me if I have not reproduced your comment precisely).
As to substance, I have nothing more to say.
Best regards,
Sasha (talk) 22:37, 5 February 2012 (UTC)

Category:Probability journals[edit]

Hi, I was you created this cat. How does it distinguish itself from Category:Statistics journals? --Guillaume2303 (talk) 05:19, 10 February 2012 (UTC)

Melcombe: sorry for stalking (I hope I am not yet non grata here);
Guillaume: although the boundary between probability and statistics is not very sharp, we do keep Category:Probabilistic inequalities and Category:Statistical inequalities, et cet. The journals in the new category (except perhaps for Annals of Mathematical Statistics) are clearly in probability and not in statistics; as to Annals of Mathematical Statistics — it is also reasonable to categorise it in both categories (see its history described in the article). Sasha (talk) 05:39, 10 February 2012 (UTC)

Just to note that categories have talk pages, just as do articles. But see also list of probability journals. Melcombe (talk) 08:50, 10 February 2012 (UTC)

  • I'm aware they have talk pages, but often people create a cat without putting it on their watchlist, which is why I posted here. I find the difference between statistics and probability a bit difficult to grasp (and me usually priding myself on being statistic-literate - although admittedly in the land of the blind: neuroscientists). To insert "probability journals" in the scientific journals category tree, would you say that they are a subcategory of "statistics journals"? Or better to put them under "mathematics journals"? Or is probability as a field on a par with mathematics? Thanks for further clarification. Also, if I am confused, other editors also might be. To reduce the risk of misclassifications, it would perhaps be helpful to include a short note at the top of the category explaining what exactly it should include. --Guillaume2303 (talk) 09:01, 10 February 2012 (UTC)
My suggestion would be to leave notes on people's talk pages, and also on project talk pages (here the mathematics and statistics projects at least, although I think there is also a journals project), that a discussion has been started, so that a range of people can join in. See probability and statistics for the distiction between probability and statistic. For the category, I was really thinking of "probability theory" rather than "probability", but retained the name used in the already-existing list of probability journals. I see "probability theory" as entirely contained within "mathematics", in parallel to, but separate from (and partly overlapping "statistics") ... but with "statistics" extending well outside just "mathematics", since it covers things that are not mathematical. Melcombe (talk) 09:21, 10 February 2012 (UTC)
  • You are of course free to start a discussion, but to me this exchnage here is not a "discussion" in the sense of people arguing different sides of an issue. All I'm doing is asking for guidance. "Probability journals" is categorized under "mathematics" journals and "statistical journals" is on the same level as mathematical journals, which seems to square with what you say above. I'll put a link to the "probability and statistics" at the top of the two journal categories, to enlighten other editors :-) --Guillaume2303 (talk) 09:42, 10 February 2012 (UTC)

List of probability journals[edit]

Hi, regarding this issue, the problem in general with this kind of lists is that they attract all those crappy OA journals that pop up all over the world, trying to make a fast buck. For an editor not in that particular field, it is very difficult to distinguish what is spam and what is legit. So I routinely remove journals that are either redlinked or (even worse) only have an external link. If you have this list watchlisted and will check for inclusion of non-notable trash, I'm fine with leaving it as it is (and can then safely remove it from my own watchlist, which is full enough), but if this is a one time thing, I'd prefer that journals only are added if they are really notable (i.e. after they have gotten an article). Thanks. --Guillaume2303 (talk) 18:16, 10 February 2012 (UTC)

The content of articles should be discussed on article talk pages. Melcombe (talk) 11:31, 13 February 2012 (UTC)
  • I am talking directlky to you and asking you a simple question. That belongs here. Are you watching that page for inclusion of spam links? --Guillaume2303 (talk) 13:18, 13 February 2012 (UTC)
You are trying to impose a policy over what should or should not appear in an article, and that belongs on an article's talk page for all to see. Melcombe (talk) 13:26, 13 February 2012 (UTC)

Citation[edit]

Re: Compound distributions. Here's the link: http://www.springerlink.com/content/u750hg4630387205/ I don't know how to cite this for wikipedia. MisterSheik (talk) 00:54, 29 February 2012 (UTC)

I have added this to compound distribution in a way that is quick and fills in details automatically. See WP:CITE for a long description of possibilities. Melcombe (talk) 01:11, 29 February 2012 (UTC)

Synthesis, eh...?[edit]

How it is OR or OR by synthesis to quote Kolmogorov, LeCam, and Pfanzagl all saying the triviality that limiting theory is irrelevant to finite samples, which is true by definition ("for every epsilon, there exists an n(epsilon) such that ...").

Also, Kolmogorov, Le Cam and Pfanzagl are not just some guys offering their opinion. Le Cam and Pfanzagl are unmatched in asymptotic theory.  Kiefer.Wolfowitz 20:42, 2 March 2012 (UTC)

See WP:SYNTHESIS (redirects to WP:OR). At the top it says "This page in a nutshell: Wikipedia does not publish original thought: all material in Wikipedia must be attributable to a reliable, published source. Articles may not contain any new analysis or synthesis of published material that serves to advance a position not clearly advanced by the sources." You have selected some valid points made by some authors in other contexts and are using them in support of some completely different thesis. Note that frequency probability is radically different from frequentist inference. The applicability (or otherwise) of limiting theory to finite samples is a completely different question from the validity of a frequency interpretation of probability or the validity of frequentist inference. Clearly only frequency inference is relevant to the statistical inference article. Melcombe (talk) 22:32, 2 March 2012 (UTC)
Melcombe, this is a case where you have not swayed me.
In the past, I have been able to see your point. This time, I think you should ask for another opinion at the mathematics project, please.  Kiefer.Wolfowitz 21:38, 3 March 2012 (UTC)
Hmmm, I've been away, but see that you've not put this back in the article. Such discussions are much better on talk pages of articles concerned. If you think Kolmogorov, LeCam, and Pfanzagl have something to say relevant to frequency probabilities then perhaps that would be a more suitable page. Melcombe (talk) 19:05, 12 April 2012 (UTC)

Coefficient of Variation[edit]

Hi Melcombe,

Thank you for reviewing my recent edits of the Coefficient of Variation article. One of my reasons for abbreviating "Geometric coefficient of variation" to "Geometric CV" was in the hope of increasing the relevance of this page for anyone googling the phrase "geometric CV" (OK, so the current 4th rank isn't bad...). I also felt that "CV" was a fairly established abbreviation within this article, so I thought I was actually making it more readable, not less so.

Also, given the references I located about GCV, do you think there is a case for deleting the external link at the bottom of the article, which refers to yet another (somewhat speculative) 'definition' of the term?

PeteLaud (talk) 15:08, 5 March 2012 (UTC)

Frequentism[edit]

Instead of edit-warring, please feel free to express yourself in a more friendly fashion. The current title, "frequency probability", is clearly an awkward, ungrammatical construction; the only thing it gets across is that wikipedia authors are illiterate dolts. Almost any article title would be better. Would "frequentist interpretation of probability" suit you better? Or just plain "frequentist interpretation"? We should continue this conversation at the talk page. linas (talk) 18:49, 12 April 2012 (UTC)

See article talk page. Melcombe (talk) 18:52, 12 April 2012 (UTC)

Thanks, an undo explained, and a long deleted article[edit]

Dear Melcombe:

Thanks for your recent declaration of a category 'Probability bounds analysis' and for putting some articles into it. I reverted an ancillary change you made to the article Applications of p-boxes and probability bounds analysis, namely the omission of the 'noinclude' tag around the reference list. Without this tag, the articles that transcluded this Applications article had screwed-up reference lists. I checked that there are no other articles linking to the Applications article, so I think the reversion should be safe.

By the way, I happened to notice a mention on your talk page of a now deleted article User_talk:Melcombe#Proposed_deletion_of_Confidence_in_statistical_conclusions. I am very intrigued by the title, even though it may "read like an essay". I cannot tell who originally wrote the article. Was it you by chance? If so, do you think I might access it somewhere?

Best regards, Scwarebang (talk) 19:58, 8 May 2012 (UTC)

I think it is somewhat unusual to include separate articles within another in the way you have, so I didn't see the point of the 'noinclude' tags. I have seen something with similar outcome using a template instead of a separate article but I don't know if that would work in this case. The problem with having an apparently separate article is that it seems not to meet the standard requirements for a good article; e.g. a lead section giving basic information about meaning and importance. You might want to seek advice on this if you have not already done so.
As to the article Confidence_in_statistical_conclusions, I did formally create this but mainly by splitting it out of the then version of Confidence interval, where an editor kept on re-inserting it despite the fact that it nothing to do with confidence intervals, but with the supposed justification that it needed to be somewhere. I did make some minor additions in an effort to turn it into a stand-alone article, but with the success you have seen. I didn't think it worth pursuing it further... I don't think I found any external sources who were worried about the sort of things that the original writer was. I don't have a copy of the final version of the article before deletion (or of any version), but you may be able to gain access via an administrator. The version immediately before removal from confidence interval was as follows (extracted from the history of confidence interval)
Section heading : Meaning of the term confidence
There is a difference in meaning between the common usage of the word 'confidence' and its statistical usage, which is often confusing to the layman. In common usage, a claim to 95% confidence in something is normally taken as indicating virtual certainty. In statistics, a claim to 95% confidence simply means that the researcher has seen something occur that only happens one time in twenty or less. If one were to roll two dice and get double six, few would claim this as proof that the dice were fixed, although statistically speaking one could have 97% confidence that they were. Similarly, the finding of a statistical link at 95% confidence is not proof, nor even very good evidence, that there is any real connection between the things linked.
When a study involves multiple statistical tests, some laymen assume that the confidence associated with individual tests is the confidence one should have in the results of the study itself. In fact, the results of all the statistical tests conducted during a study must be judged as a whole in determining what confidence one may place in the positive links it produces. If a researcher conducting a study performs 40 statistical tests at 95% confidence, she can expect about two of the tests to return false positives. If she in fact finds 3 links, the confidence associated with those links 'as the result of the survey' is actually about 32%; it's what she should expect to see two-thirds of the time.
The details of the deletion of the article are "21:55, 11 July 2011 JohnCD (talk | contribs) deleted page Confidence in statistical conclusions (Expired PROD, concern was: No sources, OR, reads like an essay)" so you may be able to contact JohnCD as a starting point, although I guess any admin would do. I suggest asking if it can be placed in your user space as it is not suitable for immediate full restoration.
I think that is as helpful as I can be. Melcombe (talk) 21:05, 8 May 2012 (UTC)

Thanks a lot for your reply. I worried about my experiment in transclusion creating a separate malformed article, and had originally presumed I could do it as a template that did not create a separate article, but was advised otherwise by the written help on the subject. Perhaps I misread it; I'll look again.

You were more than helpful about the deleted article. I can already see, alas, that it is not what I was hoping it was.

Thanks again! Scwarebang (talk) 21:36, 8 May 2012 (UTC)

Confidence?[edit]

Hi Melcombe, could you please have a look at Confidence interval#Meaning of the term "confidence". Some anonymous reverted your removal of this section and as I removed it again, restored it. From the discussion on the talk page it becomes clear he has no good understanding of the terms. Nijdam (talk) 20:28, 19 May 2012 (UTC)

I don't know what to suggest. If you look further up the articles's talk page you will see that that this has gone on since at least 2008, with the same IP editor replacing the section after removal by many different editors. Melcombe (talk) 08:29, 21 May 2012 (UTC)

Maybe you, like me, revert his reverts, to force him to be blocked for some time, if he makes to much reverts. Nijdam (talk)

Deletion of corp yields as a logistic function[edit]

Melcombe: You deleted this instead of posting a need for citation tag, which is impolite in addition to being unhelpful. There was a main listing some sources. I assume that when there is a main it is unnecessary to go back and re reference. So I have no idea what you problem is. I thought the chart of wheat yields was obviously a logistic function, and it contained a tag: FAO which of course is the Food and Agriculture Organization.

If Wikipedia is going to improve, people need to put in the citation needed tags and not arbitrarily delete things. No wonder experienced editors are quitting.Phmoreno (talk) 01:19, 3 June 2012 (UTC)

Wikipedia articles should not rely on other linked articles to explain simple concepts and they should not rely on other linked articles for citations for opinions being expressed. A ain is a pointer to wider discussion. No wonder experienced editors are quitting when experienced editors cannot follow the simplest of principles in regard to providing sources. Melcombe (talk) 11:19, 3 June 2012 (UTC)

Misleading graph[edit]

Hi. I noticed you added a link for misleading graph, which I recently created, to misuse of statistics. Being a statistician, would you care to comment on the article...if I'm missing anything major....(it still needs some expansion, but it's surprising it didn't exist before).Smallman12q (talk) 23:57, 9 July 2012 (UTC)

tag spam[edit]

I was surprised that you reverted my deletion of the tag spam on the article Arithmetic mean. References are required wherever a fact may be challenged, but not otherwise. Are there any facts you want to challenge here? I'd think that, being a statistician, you'd see immediately that this is all very basic stuff that nobody would challenge. Correct me if I'm wrong and I'll get a reference to that particular fact. Better yet, why don't you just pull down your nearest textbook and add the reference yourself. You can do it as quickly as anybody. Please don't tell me that it is too much work for you to do, but that others have to do it!

Putting up useless tags is not ok. How do I know these tags were useless? They've been up for two years, and they haven't attracted any editors to add refs. They are ugly and distract readers from the content of the article.

And please do remove any unexplained and useless tags that you see. Is two years too short for you to call them useless? Then just look seriously at unexplained tags that are 3 years old. You'll almost certainly see that they are calling for material that is not required by our policies. Once you've looked seriously at a couple of the older tags, I'm confident that you'll see the problem with tag spam. It just doesn't accomplish anything to tag without explanation.

BTW, it took me about 10 seconds to search google books and find a reference to Arithmetic mean. It may not be the best reference, but it is a reliable source. I'll remove the tag spam, and add the ref.

All the best,

Smallbones (talk) 19:52, 16 July 2012 (UTC)

WP:Cite says "However, editors are advised to provide citations for all material added to Wikipedia". In addition there is the question of notability: WP:NOTE says "Information on Wikipedia must be verifiable; if no reliable third-party sources can be found on a topic, then it should not have a separate article". So do look seriously at these tags and provide acceptable citations. And do try to understand "our policies". Melcombe (talk) 20:10, 16 July 2012 (UTC)
Seriously, you should know that the arithmetic mean material is not likely to be challenged. And I don't believe for one moment that you believe that the concept of arithmetic mean is not notable. WP:Cite is a guideline, not a policy. But it and WP:V (the policy) both say "All quotations and any material challenged or likely to be challenged must be attributed to a reliable published source using an inline citation." If you have any material there that you'd like to challenge, please do. But if you are just adding tags because you think there might possibly be a problem, you should know that this has nothing to do with any policy on Wikipedia. You can look it up. Smallbones (talk) 22:32, 16 July 2012 (UTC)
Seriously, WP:V says "However, in practice it is only necessary to provide inline citations for quotations and for any information that has been challenged or that is likely to be challenged." The adding of the tag must be considered a challenge. And no I didn't add the original tag. It is clearly inappropriate to arbitarily remove such tags without doing something to resolve the issue. Melcombe (talk) 07:38, 17 July 2012 (UTC)

"Re: User talk:MistyMorn#A_deletion[edit]

Your deletion of "A More Practical Example"[edit]

Hello

why do you think that summarizing 25 measurements with the mean and its confidence interval rather than the median is a natural thing ? Can you justify this ?

Leboudec (talk) 07:10, 20 July 2012 (UTC)

A diversion into the comparative merits of means or medians is out of place in an article about confidence intervals: Wikipedia is an encylopedia not a textbook and not a place to "teach" good satistical practice. The stuff this was added was in an introductory section intended to give a first idea of what a confidence interval is. There are is a later section "Confidence intervals for proportions and related quantities" and entries in the see also list pointing to other particular cases of using confidence intervals and it might be appropiate to add a link to confidence interval material in the article median if there is any, or even a separate section in the confidence interval article, depending on what is in median. Melcombe (talk) 10:49, 21 July 2012 (UTC)


Mizar system external links[edit]

Review request[edit]

Hi Melcombe, I made some improvements to the Mizar system page. Would you mind giving it a read, providing feedback, and discussing if, where and how it would be appropriate to inform Wikipedia readers of relevant formalized mathematical content? Yaniv256 (talk) 07:21, 22 July 2012 (UTC)

Arguments in favor of Mizar system external links[edit]

Dear Melcombe,

Your wish not to engage in a lengthy discussion is understandable. I am aware of the fact that Wikipedia is a primary target of many commercial and ideological self-promotion campaigns and pursuing discussion with such Wikipedia editors is fruitless. However, I truly believe that I do not fall in that category.

I am an economics PhD student. To the degree that I am motivated by ideology, it is my wish to help fellow Wikipedia readers appreciate the beauty of mathematical rigor. As an economist, I deal mostly with probability theory and real analysis, so this is the focus of my effort. I am not associated with any proof assistant software development group or formal reasoning research effort. In fact, I am only an amateur in the field. I may wish to do some work in it in the future, but only if and when I become convinced that my work in economics would benefit from it.

I thank you for providing some more detail about where, in your view, I was in violation of Wikimedia policy. I have read the external links guidelines and would like to make the argument that Mizar system links, of the type I have been placing, do not violate any of its directives. To make the discussion concrete I am posting here the link I placed on the sigma-field article external links section.


WP:EL states that "some acceptable links include those that contain further research that is accurate and on-topic, information that could not be added to the article for reasons such as copyright or amount of detail, or other meaningful, relevant content that is not suitable for inclusion in an article for reasons unrelated to its accuracy". The formal definition of sigma-field and the collection of proofs that have been formalized on it is on-topic on the sigma-field page. It cannot be added to the article because the amount of detail and form of presentation would overwhelm the typical reader. However, it is of interest, I believe, to current mathematics and computer science students in the advanced undergraduate and graduate level, as it allows them to sort out exactly what a sigma field is and how its properties are proved in absolute rigor.


WP:ELNO.1 states that linking to "any site that does not provide a unique resource beyond what the article would contain if it became a featured article" should be avoided. Clearly, a sigma-field featured article would not contain the body of all formalized proofs on sigma-fields. It may contain the formalized definition, one day in the future, if and when the formal language in which it is stated becomes commonly used in higher education.


WP:ELNO.13 states that "the link should be directly related to the subject of the article. A general site that has information about a variety of subjects should usually not be linked to from an article on a more specific subject ... If a section of a general website is devoted to the subject of the article, and meets the other criteria for linking, then that part of the site could be deep linked". I could not agree more. My insertion includes one internal off-topic link, the Mizar system link, that is needed in order to introduce the two on-topic external deep links.


I do hope we can have some productive discussion about these issues, as I am sure that together we can improve the way in which Wikipedia readers are made aware of formalized mathematical structures in the topic of the page they are reading.

Kind regards, Yaniv256 (talk) 05:47, 24 July 2012 (UTC)

Moving to the Mizar system talk page[edit]

I opened a Mizar system external links pro and con section to the Mizar system talk page and pasted the above arguments there too. Please feel free to contribute.Yaniv256 (talk) 15:30, 24 July 2012 (UTC)

External links should provide something recognizably useful to the topic of the page: these external links just lead to gibberish. Some abstract scheme for proving things related to sigma-fields is not directly connected to sigma-fields. Consider all the other similar schemes described in Category:Theorem proving software systems (and similar categories)... are all of these to be mentioned in every mathematical article? I don't see any of these as having been treated in the way you are trying. Why do you think that Wikipedia readers need to be made aware of formalized mathematical structures in the topic of the page they are reading? Do you think that Principia Mathematica should also be linked in the same places? I suggest you start a discussion on the mathematics project talk page ...Wikipedia talk:WikiProject Mathematics ... for a sensible/agreed way of dealing with these topics. Melcombe (talk) 15:47, 24 July 2012 (UTC)

Invitation to comment at Monty Hall problem RfC[edit]

You are invited to comment on the following probability-related RfC:

Talk:Monty Hall problem#Conditional or Simple solutions for the Monty Hall problem?

--Guy Macon (talk) 17:12, 8 September 2012 (UTC)

Errors-in-variable models : citation needed[edit]

Dear Melcombe,

About two years ago you edited a part in "Motivational Example" adding very important information on the properties of OLS. Specifically, you added a claim that the estimate is best linear predictor and that this property holds as long as the variance of errors in x_* is fixed. Today I added a "citation needed" tag to the paragraph and I think that you are the best person to edit it.

Best regards! — Preceding unsigned comment added by Karoolc (talkcontribs) 09:40, 15 October 2012 (UTC)

Category Econometrics removed: Just curious[edit]

Hi Melcombe, just curious why you removed Category: Econometrics from Multinomial logistic regression. Duoduoduo (talk) 18:11, 29 March 2013 (UTC)

...Because I saw it was in Category:Mathematical and quantitative methods (economics) which I assumed was a uncategory of Category:Econometrics, but I now see that they are the other way round. But in general I think that Category:Econometrics has too many non-specific articles which might be better accessed via subcategories. Possibly there is scope for a multinomial regression category but there are few articles that might be better merged. I'll put things back for now. However, there is essentially no econometric content, other than the single reference. Melcombe (talk) 18:23, 29 March 2013 (UTC)
Basically anything involving regression is econometric in nature and appears in various econometrics textbooks. And any kind of logistic regression is certainly used in econometrics. Duoduoduo (talk) 19:55, 29 March 2013 (UTC)
But Category:Regression analysis already appears in Category:Econometrics. Is that not enough? Certainly the content of the present article does not demonstrate any immediate relevance to econometrics. Melcombe (talk) 14:36, 30 March 2013 (UTC)
Okay. It seems to me that a good definition of econometrics would be "the theory, and the application to economic data, of regression analysis". That is, it seems to me that the two categories are identical except to the extent that an article about the application of regression specifically to some field other than economics would be in the regression category but not the econometrics category. So I would think of econometrics as a major subset of regression. As for the present article, obviously it was written by someone in a field other than economics, with non-economics examples, but that doesn't mean the topic is irrelevant to econometrics. I'll see if I can put in some economics examples. Duoduoduo (talk) 15:53, 30 March 2013 (UTC)
To me, regression analysis does not include time series anlaysis (at all), while econometrics includes much of the time-domain part of time series. Anyway, would you agree in removing the article from Category:Mathematical and quantitative methods (economics) since that includes Category:Econometrics. Melcombe (talk) 16:47, 30 March 2013 (UTC)
Yes, I agree. Duoduoduo (talk) 17:36, 30 March 2013 (UTC)
I would mention that a key part of time series analysis is autoregression and more broadly vector autoregression, and I think that "regression" includes "autoregression" and hence includes a big part of time series. Duoduoduo (talk) 17:47, 30 March 2013 (UTC)

Welcome back.[edit]

Your 8 months of silence were noted with concern.75.80.32.44 (talk) 19:46, 15 April 2013 (UTC)

Central tendency[edit]

Etiquette 101, Melcombe: If you disagree with an edit, just revert it, with a polite reason. As for my replacing information from a reliable source with something sloppily expressed and wrong, firstly mine wasn't wrong but rather just vague ("the 'center' of the data according to some definition of 'center'") in accordance with the imprecise nature of the concept itself, and secondly it appears that the sloppy thing that I replaced was not a faithful paraphrase of the source it cited, despite your assertion that you were sure since you have seen the source, as indicated by your subsequent edit summary "revise lead to accord with sources". The badly worded original would still be in there if not for my challenging it, and then re-challenging it. Duoduoduo (talk) 20:51, 20 April 2013 (UTC)

Etiquette 102: Don't remove things from other people's talk page comments, as you did here. Duoduoduo (talk) 21:01, 20 April 2013 (UTC)

Citation style of Additive model[edit]

As the sole non-anonymous content contributor to this article, could you please give your opinion on this topic? Thanks. --bender235 (talk) 08:25, 29 August 2013 (UTC)

Just to let you know -- Missing Wikipedians[edit]

You have been mentioned at Wikipedia:Missing Wikipedians. XOttawahitech (talk) 16:08, 3 January 2014 (UTC)

Category:Examples of misuse of statistics[edit]

Category:Examples of misuse of statistics, which you created, has been nominated for possible deletion, merging, or renaming. If you would like to participate in the discussion, you are invited to add your comments at the category's entry on the Categories for discussion page. Thank you. DexDor (talk) 13:55, 25 January 2014 (UTC)

Statistical population[edit]

Dear Melcombe, in 2010 you added a Noreferences in the article about Statistical population. Although I really wonder if you would need any references for such basic terminology, I still added two references now. Is it okay to remove the Noreferences? Marcocapelle (talk) 10:31, 17 May 2014 (UTC)