Resource Identifier ★★★★

An important component of the Resource Citation is the resource identification element. Similar to the Metadata Identifier, this element holds a code that uniquely identifies the resource and differentiates it from all others. With this, machines and humans can differentiate, reference and link to the resource without ambiguity

Definition

Alphanumeric identifier uniquely identifying this cited resource.

ISO Obligation

• This is an ISO optional element. There may be zero or many [0..*] identifier entries for the cited resource in the MD_DataIdentification.citation package of class MD_Identifier in a metadata record. The resource may be of type data MD_DataIdentification or of type service SV_ServiceIdentification.

Discussion

The Resource Identifier is an identifier for the dataset, not the metadata record. The Metadata Identifier provides an identifier for the metadata. A failure to distinguish between these two elements - especially as they apply to crosswalk between standards such as Dublin Core leads to a great deal of confusion and misunderstanding.

Commonly, standards like Dublin Core do not make a distinction between the metadata identifier and the resource identifier. Emerging practice, such as Google data search beta, suggests that the distinction is useful. Harvested metadata should point to a source metadata record - a ‘point of truth’ or the resource from which the record was harvested. Using this logic, the resource identifier URI would not need to be harvested by a high-level catalogue such as data.gov.au.

A common practice in GA and ABARES is for this identifier to be the same as the metadata identifier. In these cases, it can be said the authoritative metadata serves as the landing page for the data resource.

In the case where a resource may have multiple identifiers, additional instances of this element can be created. The description element must be populated in such situations to distinguish the meaning of the different identifiers.

Best Practice Recommendations

Therefore - it is recommended that this element be populated, preferably once, but more often if there are multiple identifier systems for the same resource. In the case of multiple identifiers, the description element must be populated in such situations to distinguish the meaning of the different identifiers. Code must be populated in all records and it is recommended that codeSpace be populated as well.

Common practice for Dataset metadata has been to populate this field that so that it is the same as or resolves to the metadata record itself. In this case, the metadata can be said to be the landing page for the resource.

If the metadata record is for a resource that contains more than one dataset, a best practice way to document that in the metadata needs be developed. This case may better be addressed through related metadata records.

Development of URI naming conventions to describe how the reference to the resource and the reference to metadata for that resource would be useful. This would allow easy discovery of not only the data from the metadata but solve the often more difficult problem of discovery of the metadata for a given dataset.

For Service metadata, the URL (which is itself a Uniform Resource Identifier) for the Service itself is commonly used as the Resource Identifier.

Recommended Sub-Elements

Follow the general guidance for MD_Identifier with emphasis on the following elements:

• code - (type - charstr) [1..1] Mandatory An alphanumeric value identifying an instance in the namespace.
• codespace - (type - charstr) [0..1] An optional but recommended namespace in which the code is valid. Ideally a URL path by which, when combined with the UUID, the full path to the resource landing page is provided.
• description - (type - charstr) [0..1] An optional but recommended natural language description of the meaning of the code value. Usually prepopulated in the metadata template.

Also Consider

• onlineResource - (MD_Distribution.transferOptions>MD_DigitalTransferOptions.online) is used to provide online linkage to the resource. Reccommended for Service metadata.
• MetadataIdentifier - is the preferred element to be used to provide linkage to the metadata record.
• Resource Citation - parent to this element.

Crosswalk considerations

Examples

<mdb:MD_Metadata>
....
 <mdb:identificationInfo>
  <mri:MD_DataIdentification>
  ....
    <mri:citation>
     <cit:CI_Citation>
       ....
       <cit:identifier>
        <mcc:MD_Identifier>
          <mcc:code>
          <gco:CharacterString>9547e07e-6a15-403b-8b19-488778fe0cf0
          </gco:CharacterString>
          </mcc:code>
          <mcc:codeSpace>
           <gco:CharacterString>
           http://202.49.243.69:8080/geonetwork/srv/eng/metadata/
           </gco:CharacterString>
          </mcc:codeSpace>
        </mcc:MD_Identifier>
       </cit:identifier>
       ....
     </cit:CI_Citation>
    </mri:citation>
   ....
  </mri:MD_DataIdentification>
 </mdb:identificationInfo>
....
</mdb:MD_Metadata>

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