Hi Andrew,
I'm very much unsure I understand your exact question (which is
certainly not simple-minded), but let me try to shed some light upon
some aspects of your mail.
On Fri, 2004-02-20 at 04:25, Andrew Wilson wrote:
> If (for example) 'extent' is a property of a resource and 'format' is a
> property of a resource,
I'm unsure if you mean that a resource has both a format and an extent
as separate properties? Let's be even more concrete: a resource has
format IMT:application/pdf
extent 20 pages
The meaning of "extent refines format" is then that: it is *also* true
that
format 20 pages
Is it this part you have problems with? Look at the definition of
format:
"Typically, Format may include the media-type or dimensions of the
resource. Format may be used to determine the software, hardware or
other equipment needed to display or operate the resource. Examples of
dimensions include size and duration."
It does seem to include the definition of "extent", which is precisely
"The size or duration of the resource."
> how does the abstract model explain that 'extent'
> is a refinement of 'format'? Doesn't that mean that 'extent' is not the
> same type (class?) of property as 'format'? I know the AM says properties
> can be in one-to-one refines relationships but these are only one-way
> relationships.
Yes and no. I would not call the relationship "one-way", but rather
"directed". So you can say that "format" extends "extent" if you like.
Or in other words: "the meaning of format is wider than the meaning of
extent, but includes the meaning of extent". If that is what you meant?
> So ,eg., 'extent' refines 'format' but 'format' does not and
> cannot refine 'extent'. There is another type of relationship at work here:
> one in which 'format' extends (as it were) 'extent'. If this is in the AM I
> can't see it, but, even if it is, I still have a conceptual problem because
> format and extent are *not* the same class of element, it seems to me. They
> look like they are operating at different levels of description...yes I
> supposed I am confused.
Could you elaborate on the notion of them being different classes of
elements?
/Mikael
--
Plus ça change, plus c'est la même chose
The more things change, the more they stay the same
|