On Thu, 26 Aug 2004, Eliot Christian wrote:
> At 06:02 AM 8/26/2004, Robert Sanderson wrote:
>>> I tried using the index "dc.title" with record schema "dc".
>>> But, I get disconcerting results--most of the retrieved
>>> records do not have my search term value in the XML element
>>> called "dc.title". On the surface, this looks badly broken.
>> The perils of data transformation is that information gets lost or
>> translated badly.
> Perhaps so, but in my example at LoC the server behaves correctly
> according to the standard, yet the results are counter-intuitive.
> This is an issue for the standard, not merely an implementation.
I don't think there's anything that the standard can mandate to fix this,
however? If you search a very broad index, and then request a very
narrow schema, then I don't see how we could require that the server put
the matched element into the record.
Equally a very specific index and a very narrow schema are likely to not
coincide. Searching for any of the numeric values in my CCG database
won't show up in a DC representation of the record, because DCMI in their
wisdom didn't include a generic 'numeric value' field.
Or do you mean that servers should have the same mapping for DC schema as
for the DC context set specifically?
>> [...] the issue is more that if you're mapping a field to a
>> dc index, then it should also be mapped to the same dc schema
>> element as they do have the same semantics.
> OK, then it follows that one should NOT use dc elements as
> generalized search access points. The notion of inheriting
> "existing" elements doe not make sense if such elements are
> also associated with a particular record schema.
I don't follow. Nothing (now) says that you have to expose records in the
DC schema. I think we should add a recommendation that if you allow
retrieval via the DC schema then you should have the same mappings for the
schema as for the indexes.
,'/:. Dr Robert Sanderson ([log in to unmask])
,'--/::(@)::. Special Collections and Archives, extension 3142
,'---/::::::::::. University of Liverpool
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