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Re: [higgins-dev] Higgins data model for attribute values
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In RDF there is no such thing as attributes without values. And there is no such thing as attributes with multiple values. There are only triples.
So whether in the IdAS API you have
1) 0..1 occurence of an Attribute, with 1..N occurence of Value for each Attribute, or
2) 0..N occurence of an Attribute, with 1 occurence of Value for each Attribute, or
3) 1 occurence of an Attribute, with 0..N occurence of Value for each Attribute
.. is just a matter of taste. It makes no difference in the underlying RDF data model and the higgins.owl that is built on it.
The choice that would be most consistent with the RDF way of thinking is 2).
Markus
On Jan 8, 2008 8:51 AM, Michael McIntosh <
mikemci@xxxxxxxxxx
> wrote:
higgins-dev-bounces@xxxxxxxxxxx
wrote on 01/04/2008 09:19:47 PM:
> Before addressing bug #190594, I need to know more about what the
> Higgins data model allows in an attribute's instance data.
>
> In IdAS, my understanding is that a Digital Subject may have 0..1
> occurrence of a particular Attribute, and that an Attribute may have
> 1..N occurrences of a particular type of Value.
In the case of an Attribute X, I would like to better understand the
semantic intended by the difference between the two cases where:
a) there is 0 occurence of X,,
b) there is 1 occurence of X with 0 values.
Is there a difference? What is it?
If this model changed to allow 0..N occurence of an Attribute, with 1
occurence of Value for each Attribute, what would be the difference?
If this model changed to allow 1 occurence of an Attribute, with 0..N
occurence of Value for each Attribute, what would be the difference?
> It's my understanding that each of an Attribute's values must be of
> the same data type, but that restriction isn't obvious to me in the
> Higgins OWL, and in fact, the opposite is reflected in the IdAS
> APIs. In IdAS, one can state the data type of each value they add
> to an attribute.
>
> So, we need to agree on the Higgins data model regarding the types
> of attribute values. Should the Higgins data model dictate that
> they all be of the same type, or should it allow their types to be mixed?
