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# User talk:Richard D. Gill

## Contents

- 1 Welcome!
- 2 Congratulations upon becoming a Mathematics workgroup Editor
- 3 Odds
- 4 Bayes
- 5 The Problem
- 6 You haven't actually been 'edit warring' on Wikipedia
- 7 New mathematics author
- 8 Financial Report as of March 15, 2011
- 9 Returning to Citizendium: an update on the project and how to get involved
- 10 Reality

## Welcome!

**Welcome to Citizendium as a new author!** We're very glad you've joined us. We hope you will contribute boldly and well. Here are pointers for a quick start. You'll probably also want to know how to get started as an author. Just look at Getting Started for other helpful "startup" pages, and at CZ:Home for a complete listing of help and other community pages. If you wish, just ask me to create a "personal sandbox" for you where you can test out editing and writing articles. If you need help to get going, it is a good idea to join our discussion forums. That's where we discuss policy, proposals or technical problems. You can ask any constable for help, too. Just put a note on their "talk" page. Again, welcome and thank you! We appreciate your willingness to share your expertise, and we hope to see you begin actively editing and contributing to Citizendium. Milton Beychok 18:22, 13 January 2011 (UTC)

- Hi Rick, nice to meet you here. Welcome to the club! --Boris Tsirelson 20:49, 13 January 2011 (UTC)

- Thanks Boris, it's good to be here! --Richard D. Gill 22:59, 13 January 2011 (UTC)

- Hi, Rick. A warm welcome by me, too. I am curious: What was the trouble with the Monty Hall problem? --Peter Schmitt 23:08, 13 January 2011 (UTC)

- Maybe this is a partial answer to Peter's question :-) --Boris Tsirelson 07:19, 14 January 2011 (UTC)

Everyone knows the answer is 2/3, not 1/3, and you should switch. But why? For me it is interesting that most "ordinary people" are perfectly happy with simple and convincing informal arguments, while quite a few mathematicians will endlessly argue that the "simple solutions" are plain wrong and that the problem has to be solved by a careful use of conditional probabililty. Both parties - well, on wikipedia at least - are somewhat incapable of appreciating subtleties which I think are rather important, both on points of logic and on points of model-building. So I find MHP a fantastic case-study on how to communicate probability to laypersons, on navigating the interface between mathematics and the real world. I am presently involved in forensic statistics and the role of the scientist in a (criminal) law court. It is not trivial.

It's an interesting challenge for me to try to get something of this across in the context of collaborative encyclopaedia editing, but now in a situation where professional qualifications might be a help, rather than a hindrance.

I have written a rather opinionated and argumentative paper, the preprint is on arXiv, [1], and is about to appear in print. And want to re-present some of that material here. Richard D. Gill 08:13, 14 January 2011 (UTC)

- I am aware of the many arguments this question has caused and that discussion (mainly, but not only, didactical) is still ongoing. I meant to ask what type of opposition you met on WP ... --Peter Schmitt 09:33, 14 January 2011 (UTC)

It's a question of demarcation, ownership. Hundreds of articles and several books are written on MHP (Monty Hall Problem) by popularizers of science, journalists, psychologists, educationalists. The problem was defined in a couple of sentences of rather ambiguous plain English in a popular weekly magazine. A rather smaller number of articles are written by "mathematicians", who are mostly not particularly great minds. It is not clear that the way the probem is conventionally mathematized in introductory statistics texts is the only legitimate way. Most of the "mathematicians" who pretend to offer solutions to MHP in articles (on how to teach probability and statistics) or in introductory textbooks do not analyse the original wording of the originally posed problem but rewrite the problem in a solution driven way so as to lead their students to solve it using Bayes' theorem. In order to do so they have to fill in all kinds of missing model assumptions. No attempt is ever made to motivate these assumptions. No attempt is ever made to motivate solving the problem by computation of a conditional probability. I haven't seen anywhere where the modelling stage - how to go from informal problem description to a mathematical problem which can be solved by straight forward deduction - is discussed seriously, nor anywhere where a decent motivation is given for solving the problem by computation of a conditional probability. I think it is essential that the model-building and problem-formulation stage of MHP is treated at a decent intellectual level. No wonder probability and statistics are so much abused if the difficult part of it - the model building, the bridge-building between reality and mathematics - is not taught to students ( or is taught by teachers with zero experience in that field).

The problem with WP is that any logical or mathematical analysis, however elementary, which is not recognisably present in existing published sources is forbidden. Discussions between amateurs about how to solve mathematical problems are resolved by waving rule-books. "The Truth" is an irrelevant concept. The existing literature is of rather poor quality. Most writers on MHP are not particularly good probabilists. Some highly cited references contain startling blunders. So the dedicated WP editor has no option but to write their own "reliable sources" and then hope other people will cite them, so that maybe in ten years time, new WP editors can write a decent article.

WP is, I think, generally of quite high quality in serious mathematics. The articles on elementary probability and especially on elementary statistics are however pretty abysmal. Richard D. Gill 00:35, 15 January 2011 (UTC)

- Yes, they are... But, Rick, you've created Monty Hall Problem on the mainspace (rather than your sandbox), thus, I think, it should not remain a stub for long; or are you seeking massive collaboration? :-) --Boris Tsirelson 07:05, 19 January 2011 (UTC)

- This incredibly wide and deep subject with ramifications throughout science, social science, the humanities, and leisure, needs truly massive collaboration. Richard D. Gill 00:10, 27 January 2011 (UTC)

- I'll certainly have a look, but -- right now -- don't have time for it. --Peter Schmitt 01:19, 27 January 2011 (UTC)

## Congratulations upon becoming a Mathematics workgroup Editor

Richard, I have just granted you a Mathematics workgroup Editorship. Also, as per your agreement via email that I could use your online CV, I have added a somewhat abbreviated version of your biography details and qualifications as required of Editors by the Proposal PR-2010-024 passed by our Editorial Council.

Congratulations and best regards! Milton Beychok 00:49, 18 January 2011 (UTC)

- If you should find that I have incorrectly stated anything in the Biography section of your user page, please let me know and I will make any changes required. Proposal PR-2010-024 stipulates that your biography must always remain publicly revealable. You are free to augment, delete or revise the rest of the user page in any way you wish at any time. Milton Beychok 00:49, 18 January 2011 (UTC)

- Many, many thanks! Richard D. Gill 08:21, 18 January 2011 (UTC)

## Odds

I started a new page on odds and did some work on odds ratio. Comments, rewrites, further material (links, references, examples) welcome. Richard D. Gill 17:17, 26 January 2011 (UTC)

## Bayes

I added some stuff on Bayes' theorem, in particular introduced Bayes' rule, "posterior odds equals prior odds times likelihood ratio" (or if you prefer, Bayes factor). Comments, rewrites, further material (links, references, examples) welcome. Richard D. Gill 17:17, 26 January 2011 (UTC)

- Good to see work done on Statistical significance and Bayes. I can not follow one sentence, "However it is suspect to be computing the Bayes factor or the posterior odds for a hypothesis, mean is 1.96, which is actually suggested by the data itself, z=1.06." I added a reference for the discussion of the posterior probability of 13% being associated with a frequentist P-value of 0.05 (Bayes Factor of 0.15). See the paragraph that starts with "The right-hand part" at http://www.annals.org/content/130/12/1005.full for the origin of this discussion. The goal of the discussion was to show that frequentist statistics may overstate the strength of evidence. Thanks Robert Badgett 10:49, 13 June 2011 (UTC)

## The Problem

Apologies for my blunder! Ro Thorpe 14:31, 27 January 2011 (UTC)

- No problem... and it forced me to learn how to do it myself. Richard D. Gill 08:14, 28 January 2011 (UTC)

## You haven't actually been 'edit warring' on Wikipedia

Your biography says 'edit warring'. That has a specific, negative meaning. You have been enthusiastically discussing. Garry L. Kanter 02:24, 29 January 2011 (UTC)

- True. That was quite an exaggeration. I should have added a ;-) Richard D. Gill 16:34, 29 January 2011 (UTC)

## New mathematics author

In case you don't get automatic notifications of these things, there is a new author, User:Wietze Nijdam, in your workgroup. Bruce M. Tindall 16:38, 31 January 2011 (UTC)

- Thanks!

## Financial Report as of March 15, 2011

Please read our Financial Report as of March 15, 2001 for complete details on our financial history and our current financial situation. If you have any questions, please ask them on CZ Talk:Donate. Milton Beychok 00:57, 18 March 2011 (UTC)

## Returning to Citizendium: an update on the project and how to get involved

Hello - some time ago you became part of the Citizendium project, but we haven't seen you around for a while. Perhaps you'd like to update your public biography or check on the progress of any pages you've edited so far.

Citizendium now has 16,917 articles, with 0 approved by specialist Editors such as yourself, but our contributor numbers require a boost. We have an initiative called 'Eduzendium' that brings in students enrolled on university courses to write articles for credit, but we still need more Editors across the community to write, discuss and approve material. There are some developed Mathematics articles that could be improved and approved, and some high-priority Natural Sciences articles that we don't have yet. You can also create new articles via this guide, and contribute to some Mathematics pages that have been recently edited - or to any others on Citizendium, since you're a general Author as well as a specialist Editor. You may like to contribute to discussions in the forums, and might consider running for an elected position on the Management and Editorial Councils that oversee the project.

If you have any questions, let me know via my Talk page or by leaving a message below this one. Thank you for signing up and reading this update; I hope that you will look in on our community soon. John Stephenson 16:15, 30 October 2011 (UTC)

## Reality

You might like to have a look at what's said about mathematics here. There's been some discussion already. Peter Jackson 10:51, 10 November 2011 (UTC)