Quote: "RO2B"With this index I can pick the most rare coins out of the export list. Why is there a rarity index if it's useless?
Idolenz and Numismatistuk are right. If you use the NRI to pick "the most rare coins" out of a list, then you're only picking out coins that not many Numista members have recorded. Of course this can be indeed rare medieval coins, but tokens worth next to nothing also have high NRIs.
NRI's name is misleading, I'm sure others have suggested it before but it should be outright renamed "Rarity amongst the Numista community", or something to that effect.
I think sorting by the NRI is not a reliable way to find out which coins are rare but it is quite reliable when you need to determine which coins are not rare.
I support the idea to add the NRI to exported data.
The world's most sought after coin, the legendary 1933 Penny, has a NRI score of 5. If that doesn't make it clear how little relevance it has then I don't know what to tell y'all. It's a fun little number but has no practical use at all.
Non illegitimis carborundum est. Excellent advice for all coins.
Make Numismatics Great Again!
Quote: "numinis"I think sorting by the NRI is not a reliable way to find out which coins are rare but it is quite reliable when you need to determine which coins are not rare.
I support the idea to add the NRI to exported data.
Quote: "pnightingale"The world's most sought after coin, the legendary 1933 Penny, has a NRI score of 5. If that doesn't make it clear how little relevance it has then I don't know what to tell y'all. It's a fun little number but has no practical use at all.
IMHO NRI applies to a type only (KM# 838), not to a particular year. So the legendary 1933 Penny does not have NRI.
Quote: "pnightingale"The world's most sought after coin, the legendary 1933 Penny, has a NRI score of 5. If that doesn't make it clear how little relevance it has then I don't know what to tell y'all. It's a fun little number but has no practical use at all.
IMHO NRI applies to a type only (KM# 838), not to a particular year. So the legendary 1933 Penny does not have NRI.
That's the point he was trying to make; that NRI has little regard for rarities within a common type.
NRI=100 : no Numista member has this coin in a collection
How many catalog coins are in this case?
How many of them do not even have a photo representing her?
I think it can be a useful metric. You have to understand how it is biased towards certain countries, and that some coins, although have high NRI, are not valuable nor rare really (notgeld and german states come to mind). Really modern coins (2010+) are typically 'rarer' too, for obvious reasons. For quick comparisons though, a coin with a NRI of 50 is in most cases going to be rarer and more valuable than one with <10 NRI. The ratings are usually very similar to the colnect rarity metric too.
I think it would be nice to add extra export stats though. I was hoping to have diameter exported so i can calculate how many sized flips i need to buy.
Quote: "WHATEVERR"...
I think it would be nice to add extra export stats though. I was hoping to have diameter exported so i can calculate how many sized flips i need to buy.
I understand that the NRI is an indication of how common, or not, a coin is among Numista members. But swaps ARE AMONG NUMISTA MEMBERS! A coin may be relatively common but, if it has a high NRI and you want to get it from a Numista member you may be in tough luck!
The NRI is a good indicator for a newby to avoid trading harder-to-get coins for very common ones. When I joined I swapped coins with NRI in the 20s for some in the 1s just because I was not aware of this. I could have bartered for better/nicer coins.
I support not only adding it to the export list (which should be simple) as well as to add it to the swap lists (as I also suggested).
Thanks!
Coin enthusiast, always learning
Status changed to Rejected(Xavier, 14 Feb 2019, 22:20)
