EML and OAI-PMH

[Matt Jones]

Lillian,

I hadn't looked at the OAI Protocol for Metadata Harvesting (OAI-PMH) 
in a while, so I just glanced over it as a refresher.  EML is somewhat 
orthogonal to the OAI Protocol for Metadata Harvesting, in that EML is a 
metadata content standard while OAI Protocol for Metadata Harvesting is 
a specification about how metadata harvesting systems interoperate.  It 
is much more appropriate to compare EML with other metadata standards 
such as Dublin Core.  From my reading, EML can't be compared to the OAI 
harvesting protocol in a way that indicates whether it is 'compliant' or 
not.  Nevertheless, here are the correspondences that I see:

1) EML identifiers are just strings, while the harvesting protocol 
requires that metadata records that are returned have identifiers that 
are URIs.  Thus, some EML documents might have incompatible identifiers 
because of the URI restriction. Presumably these could be transformed 
into URIs easily within the context of an OAI request, so this is really 
a trivial problem.

2) If the identifiers in an EML document are URIs, the EML document 
could be returned from an OAI harvest request as one of the metadata 
types supported by OAI-PHM.

3) EML is compatible with Dublin Core in that it contains all of the 
metadata needed to create a full Dublin Core record. Thus, because every 
OAI metadata repository must be able to return a Dublin Core record for 
each metadata item, EML could be used as the basis for such a system by 
transforming the basic EML contents into Dublin Core on request.

4) EML is far more detailed about the scientific content of ecological 
and environmental data than Dublin Core.  Dublin Core is concerned with 
bibliographic descriptors at a very coarse level, while EML includes 
these and all of the other syntax, schema, and semantic information 
needed to interpret and use a set of data in a scientific analysis.

In summary, I see no obstacles to using EML as a metadata format for the 
OAI Protocol for Metadata Harvesting.  It would be great to hear if you 
or others are considering using or are using EML in this or other ways.

Matt

Gassie, Lillian USA wrote:
> Hi:
> I'm doing some research on metadata standards.  Is EML compliant with 
> the Open Archives Initiative Protocol for Metadata Harvesting?
> 
> Thanks,
> 
> --Lillian Gassie
> Naval Postgraduate School
>