Tuesday, October 04, 2022

Is it okay for a paper or book to say `for more on this topic see Wikipedia Entry BLAH.

 One of the proofreaders for Computational Intractability: A Guide to Algorithmic Lower Bounds

(available here)

made the following objection, which raises some questions.

I object to telling readers to see a Wikipedia Entry.  Wikipedia is marvelous, but it is unstable. I have been led astray by short-lived editorial changes made by trolls. 

The proofreader is surely correct that  `See Wikipedia entry X' should be minimized. And indeed, I have gone through all of the cases we had of such things and tried to minimize them. But there are times when there seems to be no way around it. Or maybe there is but I can't see it. 

a) I want to refer to the set of problems that are (exists R)-complete. The ONLY list I know of is on Wikipedia here.

b) I want to discuss the complexity of the video game braid. There is a nice Wikipedia page about the game braid  here. There are some sites that have videos about the game, but not reallyan  explanations of it. I DID find a site that looks pretty good, here, but is that site more stable than the Wikipedia entry? There did not seem to be an official site. (I had the same issue with the 15-puzzle and some other puzzles that do not seem to have a natural official site). 

c) I want to refer the reader to a list of algorithms for discrete log. Wikipedia has a great site on this here. Is there a good article that does the same? Is it behind paywalls?

I tend to thing that the  Wikipedia sites above are stable and accurate. It helps that they are not on controversial topics.  They should be fine. Articles that are behind paywalls are much worse. As for articles on authors websites- are they more or less stable than Wikipedia?


  1. The Wikipedia license may allow you to post a copy of the page on your website. The Internet Archive lets you save a page: "Save Page Now. Capture a web page as it appears now for use as a trusted citation in the future." https://web.archive.org/

    1. Is the page on my website more stable than Wikipedia? A colleague of mine who is retiring wondered about my pointing to a copy of a paper of his on his website- when he retires will it be taken down. And long-term, when one dies what happens to their webpages? I ask non-rhetorically though I suspect there is no stable policy.

  2. I have often resorted to the Internet Archive (web.archive.org) when internet links have gone dead - just found an old AMS paper posted in the late '90s that way. If you have both the wikipedia page and the date accessed in your book, and you verify that Internet Archive has a copy, it's about the best long-term storage you'll get.

    Wikipedia itself also stores and makes accessible all old revisions, though that can be harder to navigate.

    1. On Wikipedia, you can click "View History", then get a link to a specific version of a page.

  3. For stability you can cite the current version of wikipedia page. The drawback is that you don't get the most recent information though (think of a new discrete log algorithm for instance). Yet if a new version exists the user will see it. I think this way, citing wikipedia is more than fine.

  4. "For stability you can cite the current version of wikipedia page."

    Yes. But. It crosses my mind that a citation to, for example, a recognized book, doesn't really need to be verified by the author of the paper, but if you are going to reference a wiki page, then you sort of have to read it and verify (at least for yourself) that it's not flaky and has what you need. Obviously, it may turn out that Knuth messed up the multipartition generation algorithm on pages 429-430 in Volume 4A, but (a) that's not likely and (b) it's not your problem, whereas it might be seen as your problem if the wiki page you referenced has errors...