Scientific Names and UUIDs ∞
Why Scientific Names are Bad Identifiers for Computers
Scientific names are very important in biodiversity informatics, and are way better than numbers or strange combination of characters for human to human communication. However, they are not the best choice as global identifiers for computers.
Scientific name strings have different length
More often than not identifiers end up in databases and used as a primary index to sort, connect and search data. Scientific name strings vary from 2 bytes to more than 500 bytes in length. So if they are used as keys in database they are inefficient, they waste a lot of space, become less efficient for finding or sorting information – indexes key size is usually determined by the the largest key.
UUIDs have always the same, rather small size – 16 bytes. Even when UUIDs are used in their “standard” string representation – they are still reasonably small – 36 characters. Storing them in a database as a number is obviously more efficient.
It is hard to spot differences in name strings
It is very hard for human eye to spot the difference between strings like this
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Corchoropsis tomentosa var. psilocarpa (Harms & Loes.) C.Y.Wu & Y.Tang
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Corchoropsis tomentosa var. psilocanpa (Harms & Loes.) C.Y.Wu & Y.Tang
Much easier for their corresponding UUIDs
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5edecb2b-903f-54f1-a087-b47b3b021fcd
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833c664b-7d00-5c3b-97a4-98b0ab7d0a9a
Name strings come in different encodings.
Currently Latin1, UTF-8 and UTF-16 are most popular encodings used in biodiversity. If authorship or name itself has characters outside of the 128bits of ASCII code – identically looking names will be quite different for computers.
Name strings are less stable because of their encoding
When names are moved from one database to another, from one paper to another sometimes they do not survive the trip. If you spent any time looking at scientific names in electronic form you did see something like this:
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Acacia ampliceps ? Acacia bivenosa
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Absidia macrospora V�nov� 1968
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Absidia sphaerosporangioides Man<acute>ka & Truszk., 1958
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Cnemisus kaszabi Endr?di 1964
Usually names like these had been submitted in a “wrong” encoding and some characters in them were misinterpreted. UUID on the other hand is just a hexadecimal number, which can be transitioned between various encodings more safely.
Name strings might look the same in print or on screen, but be different
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Homo sapiens
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Homo sаpiens
These two strings might look exactly the same on a screen or printed on paper, but in reality they are different. Here are their UUIDs:
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16f235a0-e4a3-529c-9b83-bd15fe722110
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093dc7f7-5915-56a5-87de-033e20310b14
The difference is that the second name has a Cyrillic а
character, which in
most cases will look exactly the same as Latin a
character. And when the
names are printed on paper there is absolutely no way to tell the difference.
UUID will tell us that these two name strings are not the same.
Nothing prevents to continue to use name strings for human interaction
One argument that people often give – it is much easier for users to type
http://biosite.org/Parus_major
than
http://biosite.org/47d61c81-5a0f-5448-964a-34bbfb54ce8b
For most of us it is definitely true and nothing prevents developers to create links of the first type, while still using UUIDs behind the scene.
Why UUIDs v5 are better than any other UUIDs as a scientific name identifier
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They can be generated independently by anybody and still be the same to the same name string
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They use SHA1 algorithm which does not have (extremely rare) collisions found for MD5 algorithm
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Same ID can be generated in any popular language following well-defined algorithm