But RDA doesn't define classes -- that's the problem. We can try to
define them for RDA, but that isn't a concept in the RDA elements that
we've been given. And I'm not at all sure that the aggregate elements
will work as classes, for reasons I gave above. So I'm trying to find
a practical solution for the moment, one that doesn't violate RDA.
(Note that RDA may NOT be RDF compatible as defined in the current RDA
documentation, and we need to work around that at the moment.)

kc

On Fri, Jan 2, 2009 at 1:54 PM, Mikael Nilsson <[log in to unmask]> wrote:
> The "right" RDF-y way to do it is to set the range of the properties to
> the appropriate class.
>
> That way, values are known to be of the right type. Application profiles
> can then decide how they want to describe instances of that class.
>
> Thus, there is no conceptual difference between the two kinds of
> "properties" you see in RDA. The substructure is only an artifact of the
> application profile.
>
> /Mikael
>
> fre 2009-01-02 klockan 13:18 -0800 skrev Karen Coyle:
>> Back to place and date...
>>
>> On Mon, Dec 22, 2008 at 9:00 AM, Alistair Miles
>> <[log in to unmask]> wrote:
>>
>> > Not directly related to any scenarios, I found that rda:placeOfCapture
>> > is a sub-property of rda:placeAndDateOfCapture, which doesn't look
>> > right. This looks like a case where Tom Delsey's "sub-elements"
>> > pattern got wrongly translated to RDF sub-properties, where rather it
>> > should be modelled in RDF as an n-ary relation.
>>
>> This still leaves us with the question of what to do with these in the
>> registry. I don't think there is an 'n-ary' capability, whatever that
>> would look like. Also, I'm not sure that these empty properties make
>> sense in the property list... I think you would want to manage them in
>> an application profile. Here are some examples from RDA:
>>
>> Place and date of capture (empty)
>>   - Place of capture
>>   - Date of capture
>>
>> Publication statement (empty)
>>   - Place of publication
>>   - Parallel place of publication
>>   - Publisher's name
>>   - Parallel publisher's name
>>   - Date of publication
>>
>> If we can imagine any use of these properties OUTSIDE of the
>> particular empty node, then I think they need to be separately defined
>> as properties, not as dependent on the empty node. We also have the
>> problem that RDA doesn't make use of classes so that there is a great
>> deal of repetition in the property/element list. As an example, there
>> are four different sets of elements that are the same as the
>> Publication statement, but that substitute one of these words for
>> Publication: Production/Publication/Distribution/Manufacture. And as
>> you can see, they also share some meaning with the "capture" concept,
>> in terms of place and date. I immediately want to take these and
>> rationalize them by defining simple properties:
>>
>>  - date
>>  - agent name
>>  - place
>>
>> ... and allowing any element to have a 'parallel' (which is the same
>> value in a different language).
>>
>> Unfortunately, at the moment we are trying to be true to RDA's
>> definition of its properties, so I need to sit on my virtual hands and
>> not mess with what they have defined.
>>
>> Any ideas what we can do with our empty nodes/Tom's sub-elements,
>> given this info? In many cases we just entered each element as a
>> separate property, including the empty node one. Is there a down side
>> to this solution?
>>
>> kc
>>
>>
>>
> --
> <[log in to unmask]>
>
> Varning! E-post till och från Sverige, eller som passerar servrar i
> Sverige, avlyssnas av Försvarets Radioanstalt, FRA.
> WARNING! E-mail to and from Sweden, or via servers in Sweden, is
> monitored by the National Defence Radio Establishment.
>



-- 
--  ---
Karen Coyle / Digital Library Consultant
[log in to unmask] http://www.kcoyle.net
ph.: 510-540-7596   skype: kcoylenet
mo.: 510-435-8234
------------------------------------