[tdwg-content] 'quantity'

Tue Dec 16 23:47:38 CET 2014

My intention in raising this concern is not to suggest that you don't need the concept of measurable-property-type-whose-value-is-an-item-from-an-enumerated(-possibly-ordered)-set, but rather just to caution that people from other domains might be surprised to see such a thing referred to as a 'quantity'. My concern is the loss of interoperability. If the latter is a goal, then you might consider tweaking the terminology. Of course if there is a unique mapping from values in the enumerated(-and-ordered)-set to scaled numbers, then 'quantity' is fine. But if the set of 'quantityTypes' that have enumerated values is distinct from the set that have scaled numeric values, then why not recognise this in the name? 

Simon

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Message: 4
Date: Tue, 16 Dec 2014 09:02:19 +0100
From: ?amonn ? Tuama [GBIF] <eotuama at gbif.org>
Subject: Re: [tdwg-content] Fwd: [dwc] quantity (#12)
To: 'Markus D?ring' <m.doering at mac.com>,	"'Paul J. Morris'"
	<mole at morris.net>
Cc: 'TDWG Content Mailing List' <tdwg-content at lists.tdwg.org>
Message-ID: <000101d01906$9d8f3250$d8ad96f0$@org>
Content-Type: text/plain;	charset="utf-8"

Simon's distinction of scaled number vs discrete set could probably be captured using DWC MeasurementOrFact properties. However, as discussed previously, we felt that because measurements of abundance/density/coverage were of fundamental importance in field studies, and in the spirit of DwC's pragmatic approach, they merited their own high level term(s), rather than "burying" them under MeasurementOrFact - hence the proposal of "quantity" and "quantityType" where the term "quantity" seems the most inclusive label for what we are trying to express.

Following John's recommendation, we have removed the references to examples in the definitions and expanded the examples in the comment section so it is clear how they are to be used.

quantity

#Definition
A number or enumeration value for the entity being quantified in quantityType.
#Comment
The terms quantity and quantityType are required to be used as a pair. The value of quantity is a number or enumeration, e.g.,  ?27? for a quantityType ?individuals?, ?12.5? for a quantityType ?%biomass?, or ?r? for a quantityType ?BraunBlanquetScale?.

quantityType

#Definition
The entity to which the number or enumeration reported in quantity refers.
#Comment
The terms quantity and quantityType are required to be used as a pair. The value of quantityType (i.e., the entity being measured) is expected to be drawn from a small controlled vocabulary with terms such as ?Individuals?, ?%Biomass?, ?%Biovolume?, ?%Species?, ?%Coverage?, ?BraunBlanquetScale?, ?DominScale?. Examples when combined with quantity values: + on DominScale; 5 on BraunBlanquetScale; 45 for %Biomass.

?amonn

-----Original Message-----
From: tdwg-content-bounces at lists.tdwg.org [mailto:tdwg-content-bounces at lists.tdwg.org] On Behalf Of Markus D?ring
Sent: 15 December 2014 15:48
To: Paul J. Morris
Cc: TDWG Content Mailing List
Subject: Re: [tdwg-content] Fwd: [dwc] quantity (#12)

"r" is a value for very few individuals in the Braun Blanquet cover abundance scale which is used a lot in vegetation studies. It is like various others a non continous scale with discrete values. I do not think we should restrict quantity to contious numeric scales. 

Markus

> Am 15.12.2014 um 15:36 schrieb Paul J. Morris <mole at morris.net>:
> 
> Markus can probably answer this question: 
> 
> What would be the expected value of QuantityType for a Quantity of "r"?
> 
> A comment Bob Morris occasionally makes is: "1 is greater than 2 for 
> sufficently large values of 1".  If some particular quantity type has 
> a standard set of codes that represent numbers, then it might be 
> appropriate to use those standard codes as values of quantity.
> 
> -Paul
> 
> On Mon, 15 Dec 2014 12:48:06 +0100
> John Wieczorek <tuco at berkeley.edu> wrote:
> 
>> Der all,
>> 
>> I am forwarding this comment from Simon Cox, which was submitted to 
>> the Darwin Core development site on Github.
>> 
>> Cheers,
>> 
>> John
>> 
>> ---------- Forwarded message ----------
>> From: Simon Cox <notifications at github.com>
>> Date: Mon, Dec 15, 2014 at 4:47 AM
>> Subject: Re: [dwc] quantity (#12)
>> To: tdwg/dwc <dwc at noreply.github.com>
>> Cc: John Wieczorek <tuco at berkeley.edu>
>> 
>> 
>> 'quantity' usually implies an amount, encoded as a scaled number.
>> In most other domains it does not include a value from an enumerated 
>> set. The latter may be called 'quality'.
>> Both quantity and quality are subclasses of 'property'.
>> 
>> ?
>> Reply to this email directly or view it on GitHub 
>> <https://github.com/tdwg/dwc/issues/12#issuecomment-66946784>.
> 
> 
> --
> Paul J. Morris
> Biodiversity Informatics Manager
> Harvard University Herbaria/Museum of Comparative Zo?logy 
> mole at morris.net  AA3SD  PGP public key available 
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> tdwg-content mailing list
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