[QUANTITY] Why quantities always have errors (Was: Re: [QUANTIT] Use-cases, role in larger scheme)

[DIDELON Pierre]

> From brian.thomas at gsfc.nasa.gov Mon Nov 17 18:03:03 2003
> From: Brian Thomas <brian.thomas at gsfc.nasa.gov>
> To: DIDELON Pierre <dide at discovery.saclay.cea.fr>
> Subject: [QUANTITY] Why quantities always have errors (Was: Re: [QUANTIT] Use-cases, role in larger scheme)
> Date: Mon, 17 Nov 2003 12:01:11 -0500
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> On Monday 17 November 2003 11:21 am, DIDELON Pierre wrote:
> > Why trying to forbidd the concept of number without error
> > if it can be introduce (for free) and claim as necessary by some people?
> 
> 	I for one believe it is "an error" to have a number without an error. 

If you have to pass a parameter to an application, to specify some input value,
you may need to transmit a value (without error), it can even be a flag.
This is a very immediat example, and we can not rule out in VO (IMO),
the usage of numbers without error, once for all, 
even if today it seems more natural to you,
SOME PEOPLE outside here want to use numbers without errors,
and ask for that possibility several times on the list (and off the list),
and it would certainly be appropriate in some cases.
Pierre.