Talk:Convex hull/GA1

GA Review

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Reviewer: Bryanrutherford0 (talk · contribs) 01:24, 9 April 2020 (UTC)

GA review (see here for what the criteria are, and here for what they are not)

1. It is reasonably well written.

   a (prose, spelling, and grammar): b (MoS for lead, layout, word choice, fiction, and lists):

   The prose standard is good. The article complies with the indicated portions of MoS, with a possible minor exception in the lead: MoS suggests that the lead section of an article this long should contain "two or three paragraphs", where this article currently has four. It's a guideline, so I won't hold back the nomination over it, but it's something to consider.

   Now three paragraphs, with more or less the same material. —David Eppstein (talk) 23:46, 9 April 2020 (UTC)

2. It is factually accurate and verifiable.

   a (reference section): b (citations to reliable sources): c (OR): d (copyvio and plagiarism):

   The article contains many citations to reputable published sources. I see no signs of plagiarism from online sources, though one random site seems to have copied text from here. Spot-checking through the sources, it looks to me as though the Artin citation should link to page 37 of the text rather than page 3, and the de Berg et al. should link to page 3 rather than page 2. Is there some convention about linking the beginning of the section rather than the cited text that I'm not aware of? For verifiability's sake it seems more helpful to have the GBooks links point to the pages that are being cited.

   I'm pretty sure the Artin link was just a copy-and-paste error (not including the final character of the url); I fixed it. For the 4 Marks book, we are citing too many different pages to choose a single one for the link in the main reference, so I just removed the link. —David Eppstein (talk) 03:50, 11 April 2020 (UTC)

3. It is broad in its coverage.

   a (major aspects): b (focused):

   The article maintains a suitable focus on its topic, and it generally achieves broad coverage, with a small exception for the concept's history. Is it known who coined this term or first began using it in its modern sense? The article mentions an early use but doesn't assert whether that is in fact the first. Is it known how or why this term came to be the standard one, rather than e.g. the other used earlier that is mentioned? The history section feels thin relative to the rest of the document, and I wish it told me more.

4. It follows the neutral point of view policy.

   Fair representation without bias:

   The article maintains a suitably neutral tone and stance toward the topic, not e.g. exaggerating its significance.

5. It is stable.

   No edit wars, etc.:

6. It is illustrated by images and other media, where possible and appropriate.

   a (images are tagged and non-free content have fair use rationales): b (appropriate use with suitable captions):

   The images used in the article have suitable tagged licenses, and they are relevant and helpful to explaining the topic. I feel that File:3D Convex Hull.tiff would be better placed in "Special cases/Finite point sets", but there's already a good 2-D illustration there, and I don't think there's room for both; it's probably still helpful where it is.

7. Overall:

   Pass/Fail:

   Excellent work! -Bryan Rutherford (talk) 13:06, 11 April 2020 (UTC)

Thanks! Re the history: I wish I knew more but have been unable to find much. I did ask on the history of science stackexchange, not about Birkhoff and the name but about Newton [1] but didn't get any usable responses. —David Eppstein (talk) 04:32, 9 April 2020 (UTC)

The history intrigued me, too. I managed to dig up a couple articles by L. L. Dines (1936, 1938) who noted the use in German of "konvexe Hülle" and complained that "hull" should properly mean the outside surface rather than the whole body. I can find "konvexe Hülle" in this doctoral thesis from 1930, for example, though I rather doubt the database coverage for German-language papers from that era is very comprehensive. XOR'easter (talk) 23:15, 9 April 2020 (UTC)

Oh, hey, thanks, XOR! Haha I love what a collaborative effort WP is! Great work, David; I should have time to check through the sources tomorrow. -Bryan Rutherford (talk) 00:08, 10 April 2020 (UTC)

The German phrase is a good suggestion; thanks! I found, from 1922, Rademacher's review of König's "Über konvexe Körper" [2] and Fejer's "Über die Lage der Nullstellen von Polynomen, die aus Minimumforderungen gewisser Art entspringen" [3]. Curiously, König himself (also 1922, [4]) doesn't appear to call it a convex hull, but merely the smallest convex body (containing a given set). I'm a bit worried this is all verging too close to WP:OR, though. —David Eppstein (talk) 04:32, 10 April 2020 (UTC)

Yes, there is a hazard of WP:OR in pursuing this. I believe that what the current version says is acceptable in this regard, since it does not synthesize the data points to argue for a conclusion (e.g., claiming that these early examples are definitively the earliest on record). To me, it seems acceptable. We could possibly add Dines' claim that by 1938, the term convex hull was "firmly intrenched in the mathematical vocabulary". XOR'easter (talk) 18:58, 10 April 2020 (UTC)

Added. That part of the Dines source actually is about the terminology and not just an example of use of the terminology. —David Eppstein (talk) 23:13, 10 April 2020 (UTC)

That is excellent work, and I'm now totally satisfied on that front. Thank you, both! One tiny concern about some of the links to source texts, and we'll be there. -Bryan Rutherford (talk) 01:22, 11 April 2020 (UTC)

And, that'll do it! This article now meets the GA standard and is promoted. Thank you for your service! -Bryan Rutherford (talk) 13:06, 11 April 2020 (UTC)