I offer my two cents on versioned terms, prompted by the 'absolutely right' phrasing :->. I am firmly straddling the fence on this question.
There are multiple science users and many technical opinions that say not having versions is absolutely wrong. The circumstances that could make 'current' *not* what you want include:
- you need to understand what definition (or other statements) was in effect when the tag was applied
- you want to understand the transitions that the definition (or other statements) has undergone over time
- the meaning of a term actually is significantly different than it used to be
- additional meanings are associated with a term (e.g., an acronym is repurposed by another organization) at a later date
I believe the last happens much more often than your confidence suggest -- perhaps especially in emerging fields or those that are newly developing documented vocabularies, extremely advanced or subjective fields, and concepts that get 'culturally adopted', e.g., turned into a pejorative (slang (that last not our problem, for the most part). I don't see how the exclusive use of non-versioned terms supports these situations.
So while I appreciate the motivations for not including versions, I think versions have to be offered by the system, and ideally should be used where unique persistent identifiers are required.
John
On Dec 16, 2010, at 13:08, Jeff deLaBeaujardiere wrote:
> Actually, my recollection is that EPSG & OGC proposed to include version numbers, and several of us argued against it and managed to convince them. I would have to dig up old emails to find out for certain who was in which camp, however.
>
> Regards,
> Jeff DLB
>
> On 2010-12-16 15:57, Lowry, Roy K. wrote:
>> Hi Jeff,
>>
>> It's interesting to see the difference of opinion between the standards developers (the idea of version number in URI came from the OGC URN specification: interesting how EPSG came to a different conclusion) and those who have to live with the consequences. The more I think about it, the more I think you and Benno are absolutely right.
>>
>> Cheers, Roy.
>> ________________________________________
>> From: cf-metadata-bounces at cgd.ucar.edu [cf-metadata-bounces at cgd.ucar.edu] On Behalf Of Jeff deLaBeaujardiere [Jeff.deLaBeaujardiere at noaa.gov]
>> Sent: 16 December 2010 19:40
>> To: John Graybeal
>> Cc: cf-metadata at cgd.ucar.edu
>> Subject: Re: [CF-metadata] Web reference to a standard name?
>>
>> On 2010-12-14 12:56, John Graybeal wrote:
>>> Just to be crystal clear, the places where you have '16' could also have 'current' (if I understand correctly what Roy was saying about their server), and the mmisw one could also be served with a particular version ID (analogous to the NERC example).
>>
>> I think it is of the utmost importance to have a URI that does not include a version number
>> and always provides the latest answer. Otherwise you have a proliferation of identifiers
>> mean the same thing but appear to change every time the overall vocabulary is updated. You
>> can also have a version-specific entry if desired.
>>
>> There were similar discussions regarding identifiers for coordinate reference system
>> identifiers from EPSG (European Petroleum Survey Group), and it was fortunately
>> recognized that a version-less URI was essential.
>>
>> -Jeff
>>
>>
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John Graybeal <mailto:jgraybeal at ucsd.edu>
phone: 858-534-2162
System Development Manager
Ocean Observatories Initiative Cyberinfrastructure Project:
http://ci.oceanobservatories.org
Marine Metadata Interoperability Project:
http://marinemetadata.org
Received on Thu Dec 16 2010 - 17:16:05 GMT
