[QUANTITY] Choosing default accuracy/units values

[Brian Thomas]

On Tuesday 18 May 2004 04:10 am, Pierre Didelon wrote:
> Hi Patrick,
>
> Patrick Dowler wrote:
> > I agree that default units and default accuracy/error should follow the
> > same rules. However, to be successful the VO really needs to get people
> > (force them if necessary) to not be lazy, so I would prefer making
> > specification of units and accuracy mandatory (in the schema) and have
> > some special values that can be easily used, like <unitless> and <exact>
> > and <uknownUnits> and <unknownAccuracy>. There should be no default
> > value.
>
> Isn't specila tag values <units>Number</units>, <accuracy>exact</accuracy>,
> <units>unknown</units> and <accuracy>unknown</accuracy> better  than
> special tag names?

	I don't think so, in particular for the units. Having representation of individual
	values as elements (tags) makes it possible to more easily restrict "valid" 
	values for accuracy/units. Tags are more amenable to use within ontologies 
	as well.

	=b.t.

-- 

  * Dr. Brian Thomas 

  * Dept of Astronomy/University of Maryland-College Park 
  * Code 630.1/Goddard Space Flight Center-NASA

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