Wikipedia talk:WikiProject Game theory

WP 1.0 bot announcement

This message is being sent to each WikiProject that participates in the WP 1.0 assessment system. On Saturday, January 23, 2010, the WP 1.0 bot will be upgraded. Your project does not need to take any action, but the appearance of your project's summary table will change. The upgrade will make many new, optional features available to all WikiProjects. Additional information is available at the WP 1.0 project homepage. — Carl (CBM · talk) 03:20, 22 January 2010 (UTC)

Request for comment on Biographies of living people

Hello Wikiproject! Currently there is a discussion which will decide whether wikipedia will delete 49,000 articles about a living person without references, here:

Wikipedia:Requests for comment/Biographies of living people

Since biographies of living people covers so many topics, many wikiproject topics will be effected.

The two opposing positions which have the most support is:

1. supports the deletion of unreferenced articles about a living person, User:Jehochman
2. opposes the deletion of unreferenced articles about a living person, except in limited circumstances, User:Collect

Comments are welcome. Keep in mind that by default, editor's comments are hidden. Simply press edit next to the section to add your comment.

Please keep in mind that at this point, it seems that editors support deleting unreferenced BLP articles if they are not sourced, so your project may want to source these articles as soon as possible. See the next, message, which may help.

Tools to help your project with unreferenced Biographies of living people

List of cleanup articles for your project

If you don't already have this and are interested in creating a list of articles which need cleanup for your wikiproject see: Cleanup listings A list of examples is here

Moving unreferenced blp articles to a special "incubation pages"

If you are interested in moving unreferenced blp articles that your project covers, to a special "incubation page", contact me, User talk:Ikip

Watchlisting all unreferenced articles

If you are interested in watchlisting all of the unreferenced articles once you install Cleanup_listings, contact me, User talk:Ikip

Ikip 05:29, 26 January 2010 (UTC)

Wikipedia:Articles for deletion/Blackmailer Paradox

All opinions welcome. ^walk victor falk ^talk 00:29, 17 July 2010 (UTC)

Multicomponent Attrition Game

I am thinking of begining the page for the Multicomponent Attrition Game. I had added it to the list of suggestions some time back, as I found it to be an interesting game which no one had started yet. If anyone has any info, references, ect, which would be useful on this article feel free to suggest them here or on my talk page. Keep in mind that I am a bit of a wikiogre, so once the interesting bits are done, there will probably still need to be some amount of cleanup, additional citations, and detail work, but the idea for me at least is to get the page started in the right direction.(I say this in the interest of honesty, not condescention)--Scorpion451 rant 18:16, 30 July 2010 (UTC)

I have created a draft of this article, and would welcome any and all comments and suggestions.--Scorpion451 rant 17:13, 6 August 2010 (UTC)

Game theory articles have been selected for the Wikipedia 0.8 release

Version 0.8 is a collection of Wikipedia articles selected by the Wikipedia 1.0 team for offline release on USB key, DVD and mobile phone. Articles were selected based on their assessed importance and quality, then article versions (revisionIDs) were chosen for trustworthiness (freedom from vandalism) using an adaptation of the WikiTrust algorithm.

We would like to ask you to review the Game theory articles and revisionIDs we have chosen. Selected articles are marked with a diamond symbol (♦) to the right of each article, and this symbol links to the selected version of each article. If you believe we have included or excluded articles inappropriately, please contact us at Wikipedia talk:Version 0.8 with the details. You may wish to look at your WikiProject's articles with cleanup tags and try to improve any that need work; if you do, please give us the new revisionID at Wikipedia talk:Version 0.8. We would like to complete this consultation period by midnight UTC on Monday, October 11th.

We have greatly streamlined the process since the Version 0.7 release, so we aim to have the collection ready for distribution by the end of October, 2010. As a result, we are planning to distribute the collection much more widely, while continuing to work with groups such as One Laptop per Child and Wikipedia for Schools to extend the reach of Wikipedia worldwide. Please help us, with your WikiProject's feedback!

For the Wikipedia 1.0 editorial team, SelectionBot 23:04, 19 September 2010 (UTC)

Some original research

on using game theory to analyze Wikipedia itself: [1]. Comments are very much welcome.radek (talk) 22:44, 20 September 2010 (UTC)

Shapley–Folkman lemma

Often used in mathematical economics and game theory, the Shapley–Folkman lemma concerns the approximate convexity of Minkowski sums of non-convex sets.

The article has received a substantial (Wikipedia) peer-review. The additional suggestions (including article assessment) of (mathematical) game-theorists would be especially helpful now.

Thanks! Best regards, Kiefer.Wolfowitz (talk) 19:32, 11 November 2010 (UTC)

Mathematical economics: Shapley-Folkman, Chichilnisky, & Mas-Colell, and Guesnerie

Re: Updates

This week User:David Eppstein created articles on the mathematical economists Andreu Mas-Colell and Graciela Chichilnisky (yesterday).

Chichilnisky iher work on international trade, development, and environmental economics has received international attention; she is known for her development of continuous social choice theory. Further, she has received national attention in the USA because of a (now settled) sex-discrimination law-suit.

I translated part of the article from French WP on Roger Guesnerie last week.

Also, another economics article started by David, the Shapley-Folkman lemma, received "Good Article" status yesterday, thanks to the reviewing of User:Jakob.scholbach, who guided the needed revisions. Further editing, especially copy-editing, would be appreciated.

Best regards,

Citation templates now support more identifiers

Recent changes were made to citations templates (such as {{citation}}, {{cite journal}}, {{cite web}}...). In addition to what was previously supported (bibcode, doi, jstor, isbn, ...), templates now support arXiv, ASIN, JFM, LCCN, MR, OL, OSTI, RFC, SSRN and Zbl. Before, you needed to place |id={{arxiv|0123.4567}} (or worse |url=http://arxiv.org/abs/0123.4567), now you can simply use |arxiv=0123.4567, likewise for |id={{JSTOR|0123456789}} and |url=http://www.jstor.org/stable/0123456789 → |jstor=0123456789.

The full list of supported identifiers is given here (with dummy values):

• {{cite journal |author=John Smith |year=2000 |title=How to Put Things into Other Things |journal=Journal of Foobar |volume=1 |issue=2 |pages=3–4 |arxiv=0123456789 |asin=0123456789 |bibcode=0123456789 |doi=0123456789 |jfm=0123456789 |jstor=0123456789 |lccn=0123456789 |isbn=0123456789 |issn=0123456789 |mr=0123456789 |oclc=0123456789 |ol=0123456789 |osti=0123456789 |rfc=0123456789 |pmc=0123456789 |pmid=0123456789 |ssrn=0123456789 |zbl=0123456789 |id={{para|id|____}} }}

Obviously not all citations needs all parameters, but this streamlines the most popular ones and gives both better metadata and better appearances when printed. Headbomb {talk / contribs / physics / books} 02:51, 8 March 2011 (UTC)

ArbCom decision on Monty Hall Problem: Decision theory

The arbitration on the Monty Hall problem is of interest to game theorists and decision theorists.

The proposed decision contains wording about "complex Bayesian solution", I note.

Also, it may be useful to be aware of the language regarding original research versus exposition using secondary sources, which is also discussed on the WikiProject Mathematics's talk page. Sincerely,  Kiefer.Wolfowitz  (Discussion) 12:21, 14 March 2011 (UTC)

Request for input in discussion forum

Given the closely linked subjects of the various religion, mythology, and philosophy groups, it seems to me that we might benefit from having some sort of regular topical discussion forum to discuss the relevant content. I have put together the beginnings of an outline for such discussion at Wikipedia:WikiProject Religion/2011 meeting, and would very much appreciate the input of any interested editors. I am thinking that it might run over two months, the first of which would be to bring forward and discuss the current state of the content, and the second for perhaps some more focused discussion on what, if any, specific efforts might be taken in the near future. Any and all input is more than welcome. John Carter (talk)

_{Automated message by Project Messenger Bot from John Carter at 15:44, 5 April 2011}

MHP FAR

I have nominated Monty Hall problem for a featured article review here. Please join the discussion on whether this article meets featured article criteria. Articles are typically reviewed for two weeks. If substantial concerns are not addressed during the review period, the article will be moved to the Featured Article Removal Candidates list for a further period, where editors may declare "Keep" or "Delist" the article's featured status. The instructions for the review process are here. Tijfo098 (talk) 22:59, 7 April 2011 (UTC)

Partnership game

There are zero links to this one-paragraph article and no discussion except the project banner. If the concept is important there should be some in-links from other game theory articles.

There are partnership games in another sense, played by four or more people in pairs: whist, doubles tennis, best ball golf, and so on.--P64 (talk) 20:03, 8 April 2011 (UTC)

Adding link for easier examination: partnership game CRETOG8(t/c) 20:50, 8 April 2011 (UTC)

That article needs more context before it's worth linking to. My quick search just now for partnership game stuff makes it look like it refers to something like a symmetric principal-agent problem, where there are partners who jointly benefit from an enterprise, but each has incentive to shirk. Two links: [2], [3]. CRETOG8(t/c) 20:56, 8 April 2011 (UTC)

That is worth an article, even if limited to two partners which seems unnecessary. The current stub makes it seem trivial to me, specifying identical payoffs pairs ^P P^ for all strategy pairs ^S1 S2^, I think it means.

Perhaps the others may be called "pairs game" or "doubles game". At the moment I would write that article only about five times longer than this one ;-) which content that would not justify getting started, certainly not worth disambiguation! --P64 (talk) 17:05, 9 April 2011 (UTC)

I've asked for feedback from the original creator of the article. It's possible they can provide more context. CRETOG8(t/c) 17:57, 9 April 2011 (UTC)

I'm not sure if they invented the term, but I first encountered it in Josef Hofbauer and Karl Sigmund's Evolutionary games and population dynamics. On page 82 they define it in terms of symmetry of payoff matrices. A game is a partnership game if the payoff to all players is the same for a given strategy profile. For H&S, partnership games are pure coordination games.

A quick google search reveals some inconsistency in usage. [4] use it to define a class of games that includes prisoner's dilemma like games. It looks like H&S use is common in biology, while partnership games have more than one different meaning in the economics. --best, kevin [kzollman][talk] 17:21, 19 April 2011 (UTC)

Economics sidebar: Game theory and Mathematical methods

Outside thoughts are requested for the economics sidebar. One question is whether the term the JEL's Mathematical and Quantitative Methods should be called "Technical Methods", following the old New Palgrave (but not the current NP, which follows the JEL). Another question is whether game theory should be classified among the mathematical/quantitative methods (following the JEL) or among the economic subfields, alongside information economics and industrial organization (not following the JEL). Thanks,  Kiefer.Wolfowitz  (Discussion) 08:56, 11 April 2011 (UTC)

Typology and toplogy of 2x2 games

We have a semi-haphazard collection of articles on 2x2 (matrix) games, and some typologies there of, e.g. coordination game. Besides that well-known class, there are bunch of ad-hoc typologies that vary between authors, e.g. some define anti-coordination game [5], others define discoordination games [6]. More recently 2x2 games have been classified using topology with some elements of graph and group theory by "alikeness" in [7], e.g. symmetric games. If someone has broad knowledge in this area an overview article would be nice; call it 2x2 games perhaps? Tijfo098 (talk) 06:39, 9 May 2011 (UTC)

I see we have symmetric game, so that's a good start (even though not citing that book yet). Tijfo098 (talk) 07:09, 9 May 2011 (UTC)

2x2 isn't the best way to categorize these. Coordination games and symmetric games aren't only 2x2. I'm not sure about the others. That said, 2x2 games are used a lot in illustrations, so a list-article like List of 2x2 games might be worthwhile. CRETOG8(t/c) 15:43, 9 May 2011 (UTC)

I know that symmetric and coordination games generalize to more than 2x2 (even though the coordination game article doesn't seem to give the general def [8]). There is is however substantial literature on the taxonomy of 2x2 games (see links above), which justifies an article. It is probably better to create 2x2 games than to cram the taxonomy at Coordination game#Other games with externalities as it's currently done. Tijfo098 (talk) 16:05, 9 May 2011 (UTC)

Monty Hall Problem

Progress on the article on Monty Hall Problem continues to be mired in fruitless debate: not on the question of whether you should switch or stay, but on the question whether the problem is a wonderful brain-teaser whose surprising solution can be understood by anyone, or whether it is a probability paradox which has to be solved using probability calculus and Bayes' theorem. There are indeed different literatures on the problem: popular; elementary probability; elementary game theoretic ... and hence readers with very different needs.

The reason I draw attention to the topic here is that just recently, A.V. Gnedin (in several preprints on arXiv.org) has discovered that the game theoretic notion of domination can be used to splendid effect, leading to a powerful argument for switching which does not need any probability input at all!

So 1) I hope that this will entertain all lovers of game theory on wikipedia, and 2) I hope it will motivate some people here to join in the editing of the article on Monty Hall problem. What that article badly needs, in my opinion, is fresh editors who have enough mathematical background that they can appreciate different solutions from different points of view and with talent for explaining mathematical ideas to ordinary people. Richard Gill (talk) 09:52, 11 June 2011 (UTC)

From a purely expositional point of view, I guess I must disappoint you. Neither the matrix form (as used in the article by Gnedin), nor the game tree form is particularly easy to understand for casual readers. Moreover, in analysing this as a game, one has to make assumptions about the utility of the game host, which, while interesting, further complicate the picture. I doubt that this will help anyone without a good knowledge of gametheory to understand the problem. --Xeeron (talk) 10:27, 16 June 2011 (UTC)

Shapley–Folkman lemma: FA copy-editing

Today mathematician Lloyd Shapley won the Nobel Prize in Economics (finally), and so Nobel Week would be a good time for a related featured-article.

The featured-article nomination for Shapley–Folkman lemma was stalled because of concerns about the professional-prose criterion. Help with copy-editing would be great.

In my dreams, I could imagine an animated illustration ... :)

Kiefer.Wolfowitz 17:26, 15 October 2012 (UTC)

Hobbesian trap

Hobbesian trap: help appreciated :) --Tobias1984 (talk) 10:27, 3 April 2013 (UTC)

Bankruptcy problem is up for deletion

Note that the Bankruptcy problem is up for deletion at Wikipedia:Articles for deletion/Bankruptcy problem. Comments welcome. --Mark viking (talk) 20:31, 1 March 2014 (UTC)

Leaflet for Wikiproject Game Theory at Wikimania 2014

Hi all,

My name is Adi Khajuria and I am helping out with Wikimania 2014 in London.

One of our initiatives is to create leaflets to increase the discoverability of various wikimedia projects, and showcase the breadth of activity within wikimedia. Any kind of project can have a physical paper leaflet designed - for free - as a tool to help recruit new contributors. These leaflets will be printed at Wikimania 2014, and the designs can be re-used in the future at other events and locations.

This is particularly aimed at highlighting less discoverable but successful projects, e.g:

• Active Wikiprojects: Wikiproject Medicine, WikiProject Video Games, Wikiproject Film

• Tech projects/Tools, which may be looking for either users or developers.

• Less known major projects: Wikinews, Wikidata, Wikivoyage, etc.

• Wiki Loves Parliaments, Wiki Loves Monuments, Wiki Loves ____

• Wikimedia thematic organisations, Wikiwomen’s Collaborative, The Signpost

The deadline for submissions is 1st July 2014

For more information or to sign up for one for your project, go to:

Project leaflets
Adikhajuria (talk) 12:59, 27 June 2014 (UTC)

Comment on the WikiProject X proposal

Hello there! As you may already know, most WikiProjects here on Wikipedia struggle to stay active after they've been founded. I believe there is a lot of potential for WikiProjects to facilitate collaboration across subject areas, so I have submitted a grant proposal with the Wikimedia Foundation for the "WikiProject X" project. WikiProject X will study what makes WikiProjects succeed in retaining editors and then design a prototype WikiProject system that will recruit contributors to WikiProjects and help them run effectively. Please review the proposal here and leave feedback. If you have any questions, you can ask on the proposal page or leave a message on my talk page. Thank you for your time! (Also, sorry about the posting mistake earlier. If someone already moved my message to the talk page, feel free to remove this posting.) Harej (talk) 22:47, 1 October 2014 (UTC)

One of your project's articles has been featured

Hello, Please note that Game design, which is within this project's scope, has been selected as one of Today's articles for improvement. The article was scheduled to appear on Wikipedia's Community portal in the "Today's articles for improvement" section for one week, beginning today. Everyone is encouraged to collaborate to improve the article. Thanks, and happy editing! Delivered by Theo's Little Bot at 01:00, 8 December 2014 (UTC) on behalf of the TAFI team

WikiProject X is live!

Hello everyone!

You may have received a message from me earlier asking you to comment on my WikiProject X proposal. The good news is that WikiProject X is now live! In our first phase, we are focusing on research. At this time, we are looking for people to share their experiences with WikiProjects: good, bad, or neutral. We are also looking for WikiProjects that may be interested in trying out new tools and layouts that will make participating easier and projects easier to maintain. If you or your WikiProject are interested, check us out! Note that this is an opt-in program; no WikiProject will be required to change anything against its wishes. Please let me know if you have any questions. Thank you!

Note: To receive additional notifications about WikiProject X on this talk page, please add this page to Wikipedia:WikiProject X/Newsletter. Otherwise, this will be the last notification sent about WikiProject X.

Harej (talk) 16:57, 14 January 2015 (UTC)

Braess's paradox listed at Requested moves

A requested move discussion has been initiated for Braess's paradox to be moved to Braess' paradox. This page is of interest to this WikiProject and interested members may want to participate in the discussion here. —RMCD bot 22:33, 28 May 2015 (UTC)

Voting paradox listed at Requested moves

A requested move discussion has been initiated for Voting paradox to be moved to Condorcet voting paradox. This page is of interest to this WikiProject and interested members may want to participate in the discussion here. —RMCD bot 01:45, 9 January 2017 (UTC)

To opt out of RM notifications on this page, transclude {{bots|deny=RMCD bot}}, or set up Article alerts for this WikiProject.

Range voting listed at Requested moves

A requested move discussion has been initiated for Range voting to be moved to Score voting. This page is of interest to this WikiProject and interested members may want to participate in the discussion here. —RMCD bot 00:45, 19 January 2017 (UTC)

To opt out of RM notifications on this page, transclude {{bots|deny=RMCD bot}}, or set up Article alerts for this WikiProject.

WikiJournal of Science promotion

The WikiJournal of Science is a start-up academic journal which aims to provide a new mechanism for ensuring the accuracy of Wikipedia's scientific content. It is part of a WikiJournal User Group that includes the flagship WikiJournal of Medicine.. Like Wiki.J.Med, it intends to bridge the academia-Wikipedia gap by encouraging contributions by non-Wikipedians, and by putting content through peer review before integrating it into Wikipedia. Since it is just starting out, it is looking for contributors in two main areas: Editors See submissions through external academic peer review Format accepted articles Promote the journal Authors Original articles on topics that don't yet have a Wikipedia page, or only a stub/start Wikipedia articles that you are willing to see through external peer review (either solo or as in a group, process analagous to GA / FA review) Image articles, based around an important medical image or summary diagram If you're interested, please come and discuss the project on the journal's talk page, or the general discussion page for the WikiJournal User group.

T.Shafee(Evo&Evo)^talk 10:29, 24 January 2017 (UTC)

Rock–paper–scissors listed at Requested moves

A requested move discussion has been initiated for Rock–paper–scissors to be moved to Rock, paper, scissors. This page is of interest to this WikiProject and interested members may want to participate in the discussion here. —RMCD bot 07:29, 25 May 2017 (UTC)

To opt out of RM notifications on this page, transclude {{bots|deny=RMCD bot}}, or set up Article alerts for this WikiProject.

Rock-paper-scissors listed at Requested moves

A requested move discussion has been initiated for Rock-paper-scissors to be moved to Rock, paper, scissors. This page is of interest to this WikiProject and interested members may want to participate in the discussion here. —RMCD bot 04:29, 26 May 2017 (UTC)

To opt out of RM notifications on this page, transclude {{bots|deny=RMCD bot}}, or set up Article alerts for this WikiProject.

WikiProject collaboration notice from the Portals WikiProject

The reason I am contacting you is because there are one or more portals that fall under this subject, and the Portals WikiProject is currently undertaking a major drive to automate portals that may affect them.

Portals are being redesigned.

The new design features are being applied to existing portals.

At present, we are gearing up for a maintenance pass of portals in which the introduction section will be upgraded to no longer need a subpage. In place of static copied and pasted excerpts will be self-updating excerpts displayed through selective transclusion, using the template {{Transclude lead excerpt}}.

The discussion about this can be found here.

Maintainers of specific portals are encouraged to sign up as project members here, noting the portals they maintain, so that those portals are skipped by the maintenance pass. Currently, we are interested in upgrading neglected and abandoned portals. There will be opportunity for maintained portals to opt-in later, or the portal maintainers can handle upgrading (the portals they maintain) personally at any time.

Background

On April 8th, 2018, an RfC ("Request for comment") proposal was made to eliminate all portals and the portal namespace. On April 17th, the Portals WikiProject was rebooted to handle the revitalization of the portal system. On May 12th, the RfC was closed with the result to keep portals, by a margin of about 2 to 1 in favor of keeping portals.

There's an article in the current edition of the Signpost interviewing project members about the RfC and the Portals WikiProject.

Since the reboot, the Portals WikiProject has been busy building tools and components to upgrade portals.

So far, 84 editors have joined.

If you would like to keep abreast of what is happening with portals, see the newsletter archive.

If you have any questions about what is happening with portals or the Portals WikiProject, please post them on the WikiProject's talk page.

Thank you.    — The Transhumanist   10:57, 31 May 2018 (UTC)

Nucleolus

Why is nucleolus included in the list of articles to create? - Astrophobe (talk) 22:08, 12 September 2019 (UTC)

Nucleolus, the cell biology topic, is created. But nucleolus (game theory) has not. We do have Cooperative_game_theory#The_nucleolus. Expanding that section and then splitting out if it gets too big, may be the way to go. --{{u|Mark viking}} {Talk} 22:34, 12 September 2019 (UTC)

Request for information on WP1.0 web tool

Hello and greetings from the maintainers of the WP 1.0 Bot! As you may or may not know, we are currently involved in an overhaul of the bot, in order to make it more modern and maintainable. As part of this process, we will be rewriting the web tool that is part of the project. You might have noticed this tool if you click through the links on the project assessment summary tables.

We'd like to collect information on how the current tool is used by....you! How do you yourself and the other maintainers of your project use the web tool? Which of its features do you need? How frequently do you use these features? And what features is the tool missing that would be useful to you? We have collected all of these questions at this Google form where you can leave your response. Walkerma (talk) 04:24, 27 October 2019 (UTC)

Rock–paper–scissors listed at Requested moves

A requested move discussion has been initiated for Rock–paper–scissors to be moved to Rock-paper-scissors. This page is of interest to this WikiProject and interested members may want to participate in the discussion here. —RMCD bot 11:15, 31 October 2019 (UTC)

To opt out of RM notifications on this page, transclude {{bots|deny=RMCD bot}}, or set up Article alerts for this WikiProject.

John Forbes Nash Jr. listed at Requested moves

A requested move discussion has been initiated for John Forbes Nash Jr. to be moved to John Nash. This page is of interest to this WikiProject and interested members may want to participate in the discussion here. —RMCD bot 05:16, 18 January 2022 (UTC)

To opt out of RM notifications on this page, transclude {{bots|deny=RMCD bot}}, or set up Article alerts for this WikiProject.

Project-independent quality assessments

Quality assessments by Wikipedia editors rate articles in terms of completeness, organization, prose quality, sourcing, etc. Most wikiprojects follow the general guidelines at Wikipedia:Content assessment, but some have specialized assessment guidelines. A recent Village pump proposal was approved and has been implemented to add a |class= parameter to {{WikiProject banner shell}}, which can display a general quality assessment for an article, and to let project banner templates "inherit" this assessment.

No action is required if your wikiproject follows the standard assessment approach. Over time, quality assessments will be migrated up to {{WikiProject banner shell}}, and your project banner will automatically "inherit" any changes to the general assessments for the purpose of assigning categories.

However, if your project has decided to "opt out" and follow a non-standard quality assessment approach, all you have to do is modify your wikiproject banner template to pass {{WPBannerMeta}} a new |QUALITY_CRITERIA=custom parameter. If this is done, changes to the general quality assessment will be ignored, and your project-level assessment will be displayed and used to create categories, as at present. Aymatth2 (talk) 14:03, 11 April 2023 (UTC)

Condorcet paradox listed at Requested moves

A requested move discussion has been initiated for Condorcet paradox to be moved to Condorcet cycle. This page is of interest to this WikiProject and interested members may want to participate in the discussion here. —RMCD bot 19:01, 13 August 2024 (UTC)

To opt out of RM notifications on this page, transclude {{bots|deny=RMCD bot}}, or set up Article alerts for this WikiProject.