Add more flag similarities

[gaetjen]

Countries in flag_similarity.csv were partially ordered alphabetically, partially grouped by similarity. I suggest grouping everything by similarity to make editing and finding related entries easier. Sorting everything alphabetically could also make sense.

Added the following pairs for flag similarity (descriptions only in English and German so far. For other languages I don't know enough to add them so I only added the countries).

• Jordan, Sahrawi Arab Democratic Republic
  • Major difference: decorations of same type in different positions (star on left vs. moon and star in center)
  • Negligible difference: different geometry (Jordan has longer arrow)
• Jordan, Palestine
  • Critical difference: Presence of star (Jordan)
  • Negligible difference: different geometry (Jordan has longer arrow)
• Sahrawi Arab Democratic Republic, Palestine
  • Critical difference: Presence of moon and star (Sahrawi Arab Democratic Republic)
• Slovenia, Slovakia
  • Minor/Negligible difference: slightly different colours (Slovenia has a lighter shade of blue, is not always consistent, darker versions also exist)
  • Minor difference: different decoration of same type in same position (different coat of arms, Slovenian coat of arms slightly smaller and higher)
• Russia, Slovakia
  • Critical difference: presence of coat of arms
• Russia, Slovenia
  • Critical difference: presence of coat of arms

Did NOT include:

• Sudan with Sahrawi Arab Democratic Republic or Jordan
  • 1 critical difference (presense absence of decoration) + 1 major difference (rotated colors)

[aplaice]

Thanks very much for the thoughtful contribution!

Ordering by group definitely makes sense!

Russia, Slovakia, Slovenia

(I delved deep into the colour differences, but they turned out to be mostly irrelevant.)

(I'm using the colours from the SVGs themselves, not from the relevant Wikipedia articles. Slovakia, Slovenia, Russia.)

	Colour/feature			ΔE/similarity	Type of difference
Slovakia-Russia	Red	Slovakia #EE1C25	Russia #D52B1E	11	n
Slovakia-Russia	Blue	Slovakia #0B4EA2	Russia #0039A6	20	n
Slovakia-Russia	Ratio	Slovakia 2:3	Russia 2:3	=	-
Slovenia-Russia	Red	Slovenia #FF0000	Russia #D52B1E	25	n
Slovenia-Russia	Blue	Slovenia #005CE5	Russia #0039A6	19	n
Slovenia-Russia	Ratio	Slovenia 1:2	Russia 2:3	≠	m
Slovakia-Slovenia	Red	Slovakia #EE1C25	Slovenia #FF0000	17	n
Slovakia-Slovenia	Blue	Slovakia #0B4EA2	Slovenia #005CE5	31	m
Slovakia-Slovenia	Ratio	Slovakia 2:3	Slovenia 1:2	≠	m

According to this, Slovakia-Russia is 1C 0M 0m 1n (Coat of arms absent; colours subtly different)
Slovenia-Russia is 1C 0M 1m 1n (Coat of arms absent; proportions different; colours subtly different)
Slovakia-Slovenia is 0C 1M 2m 1n or 0C 0M 3m 1n (depending on whether the coat of arms is determined to be in the same position or a different one — it doesn't affect "passing the criterion") (B31, R17; Proportions different)

(Is a difference in proportion of 2:3 vs. 1:2 slight or subtle? I strongly lean towards slight and that'd be consistent with previous choices — we concluded the Monaco-Indonesia difference in width to be minor (proportions 4:5 vs. 2:3).)

Hence, according to the guidelines, the Slovak-Russian and the Slovak-Slovenian similarities, but not the Slovenian-Russian one should be included...
Guidelines aside, I think that this mostly makes sense — due to the different geometries, it seems unlikely that users would confuse the Russian and Slovenian flags — even if it's slightly weird that similarity isn't transitive.

Jordan, Palestine, SADR

We had previously categorised the Palestine-Jordan triangle difference as "minor" and I still think that that's the case — the length of the triangle differs considerably. Hence, the Jordan-Palestine difference is 1C 0M 1m and the flags are not similar.

I don't think that the difference between Jordan and SADR falls under any of the categories — a crescent and a star is different to a single star (or even any number of stars). (Aruba/Curaçao is a closely related case, but IMO "two stars vs. one star of the same colour, in different positions" is more similar than "a star and a crescent vs. one star, of different colours, in different positions.)

Palestine/SADR are indeed similar. (The greens are identical, the red ΔE* is 5.)

Summary

Hence, overall, I think that only the Slovak-Russian, Slovak-Slovenia and Palestine-Sahrawi Arab Democratic Republic similarities should be added.

Just to clarify, in case the guidelines seem rigid and nonsensical: The idea of the guidelines is that "similarity" is usually on a spectrum, where flags would be extremely easy to confuse on one end (e.g. Nicaragua/El Salvador or Monaco/Indonesia) and rather unlikely to be confused at the other (e.g. France/Italy). Having too many similarity descriptions can potentially distract/annoy/confuse users, so it's important to find a good cut-off point. IMO the current guidelines do a relatively good job of providing such a cut-off point. Obviously, it'd be better if we had hard data on which flags users confused, but unfortunately Anki doesn't collect such data and it'd be pretty hard to collect in a privacy-preserving way.

@axelboc, should/could we have your amazing, extremely thorough categorisation copied somewhere better exposed and globally-editable or easily-commentable (such as a discussion or a Wiki page) and linked to from CONTRIBUTING.md? Having old decisions regarding what was/wasn't accepted and why, is often useful for reference.

[josealberto4444]

Maybe this is a good opportunity for solving #404 as well? =)

[axelboc]

@axelboc, should/could we have your amazing, extremely thorough categorisation copied somewhere better exposed and globally-editable or easily-commentable (such as a discussion or a Wiki page) and linked to from CONTRIBUTING.md? Having old decisions regarding what was/wasn't accepted and why, is often useful for reference.

Done! https://github.com/anki-geo/ultimate-geography/wiki/Flag-similarities - good call on the wiki page 💯 I'll add a link to it in the contributing guide now.

@aplaice can I please leave you to add the country pairs that you've newly audited? (With 🔨 or something next to the three similarities that will be added once this PR is merged, maybe?)

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Hence, overall, I think that only the Slovak-Russian, Slovak-Slovenia and Palestine-Sahrawi Arab Democratic Republic similarities should be added.

@gaetjen can you please update the PR as per @aplaice's feedback? Once you're done, we'll work on the translations. Thanks! 🙌

[axelboc]

I'll add a link to it in the contributing guide now.

... and, done! https://github.com/anki-geo/ultimate-geography/blob/master/CONTRIBUTING.md#flag-similarity-field -- Of course, feel free to edit the wiki page as you see fit @aplaice

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Maybe this is a good opportunity for solving #404 as well? =)

@josealberto4444 I think the fix is pretty much ready to go. There's a couple of extra fields to fix, but seems easy-enough. Want to open a PR?

[josealberto4444]

@josealberto4444 I think the fix is pretty much ready to go. There's a couple of extra fields to fix, but seems easy-enough. Want to open a PR?

Done! ^^ #432

[aplaice]

Thanks @josealberto4444 for taking care of #404!

Thanks @axelboc for creating the wiki page!

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@aplaice can I please leave you to add the country pairs that you've newly audited? (With hammer or something next to the three similarities that will be added once this PR is merged, maybe?)

Done. Relevant parts copied below for ease of reference:

• ❌ Jordan / Palestine => 1C 0M 1m 0n (presence of star, length of triangle)
• ❌ Jordan / Sahrawi Arab Democratic Republic => different symbol in different position
• ✔️ Palestine / Sahrawi Arab Democratic Republic => 1C 0M 0m 1n (presence of symbol, shades of colours G0 R5) 🔨
• ✔️ Russia / Slovakia => 1C 0M 0m 1n (presence of coat of arms, shades of colours B20 R11) 🔨
• ❌ Russia / Slovenia => 1C 0M 1m 1n (presence of coat of arms, width, shades of colours B19 R25)
• ✔️ Slovakia / Slovenia => 0C 0M 3m 1n (coat of arms, width, shade of blue B31 R17) 🔨

[axelboc]

FYI, I'm going to try to finish this PR.

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The case of Jordan/SADR is interesting. The major difference "decorations of same type in different position" was initially meant to care only about the type of decoration (i.e. symbol vs. coat of arms vs. glyph vs. ...), and not the decorations themselves. So two symbols appearing in different positions was supposed to fit the rule, regardless of the symbols themselves.

That being said, from a subjective point of view, I agree with you @aplaice that the symbols of Jordan and SADR are different enough to not qualify for major difference status. If the stars had the same number of branches, maybe ... Anyway, so perhaps we should clarify the guidelines somehow?

Note that if we do add the critical difference suggested in #469 (comment), then Jordan/SADR would still not qualify, as it would have 1C, 0M, 1m (i.e. the minor difference between the two triangles would disqualify it). I don't know if any other pair of flag would qualify. We decided not to add an additional critical difference to the guidelines.

[axelboc]

• Technically narrower should go last because it's a minor difference, but it felt clearer in first position.
• I chose not to mention the position of the coat of arms, as I felt like its size difference was significant-enough on its own and more concise to describe.

[axelboc]

I don't think we need to mention "star and crescent" here -- the term "symbol" seems clear-enough.