Edurep:Identifiers/en

Nederlands

English

Identifiers are used to uniquely identify an entity. In the context of Edurep we need 3 types of identifiers: object identifiers, record identifiers and collection identifiers.

Object Identifier

The object identifier is used to uniquely identify the learning resource.

• not to be confused with the record identifier
• the object identifier is not intended to metadata the URL to the learning resource:
  • the URL to the learning resource may be used additionally as an object identifier, please note that the order of URL parameters does not determine the functionality of a URL, but it does determine its use as an object identifier
  • unlike the URL, the object identifier must not change if the physical location of the learning object changes.

The object identifier is also used to create links between entities in Edurep, specifically between a learning resource metadata record and a social metadata record.

Such a metadata link can only be made with a URI. RFC 2396 is used as the definition of a URI. Since an object identifier may appear multiple times, a URI definition may appear alongside other definitions. For example, a formal URN naming can be chosen when it is available.

NL LOM

Specification

(leading)

<!-- to enable linking, Urn ISBN notation is preferred -->
<lom>
  <general>
    <catalogentry> 
      <catalog>URI</catalog>
      <entry> 
        <langstring xml:lang="x-none">urn:isbn:0-395-36341-1<langstring>
      <entry>
    </catalogentry> 
    <catalogentry> 
      <catalog>ISBN</catalog>
      <entry> 
        <langstring xml:lang="x-none">0-395-36341-1<langstring>
      <entry>
    </catalogentry> 
  </general>
</lom>

If there is no formal URN scheme, a custom scheme can also be used in the URI. The homemade scheme may not be one of the known URI schemes .

<lom>
  <general>
    <catalogentry> 
      <catalog>URI</catalog>
      <entry> 
        <langstring xml:lang="x-none">lesidee:138<langstring>
      <entry>
    </catalogentry> 
    <catalogentry> 
      <catalog>LESIDEE.NL</catalog>
      <entry> 
        <langstring xml:lang="x-none">138<langstring>
      <entry>
    </catalogentry>
  </general>
</lom>

Schema.org

Specification (identifier)

(leading)

In schema.org, object identifiers are placed in the schema:identifier field. Furthermore, depending on the type of entity, a number of specific identifier fields are available, for example:

• schema:isbn for the Book type
• schema:gtin for the Product type

{
  "@context": {
    "schema": "https://schema.org/"
  },
  "schema:identifier": [
    "http://example.org/resource/1",
    "urn:isbn:978-1-56619-909-4"
  ],
  "schema:isbn": "978-1-56619-909-4"

}

SMO

In a metadata record of an SMO review, the object identifier of the learning material that is the subject of the review is placed in the hreview:info field. This value is used to create the link with the learning material metadata record.

<smd:smo xmlns:smd="http://xsd.kennisnet.nl/smd/1.0/" xmlns:hreview="http://xsd.kennisnet.nl/smd/hreview/1.0/">
  <hreview:hReview>
    <hreview:info>https://www.kennisnet.nl</hreview:info>
  </hreview:hReview>
</sdm:smo>

In the schema.org Review representation this is the schema:itemReviewed attribute.

{
  "@context": {
    "schema": "https://schema.org/"
  },
  "schema:review": {
    "@type": "schema:Review",
    "schema:itemReviewed": "https://www.kennisnet.nl"
  }
}

Record Identifier

The record identifier is used to identify a metadata record in Edurep.

• not to be confused with the object identifier

We distinguish a number of record identifiers in Edurep:

• recordId: the identifier with which the record was placed in Edurep by the provider (usually the OAI-PMH record identifier) (not guaranteed unique within Edurep)
• uploadId: the recordId prefixed with the identifier of the repository (making it unique within Edurep)
• jsonldId: the upload identifier that can be used in the @id of a schema.org record (for LOM collections prefixed with "jsonld-from-lom")
• smoId: the record identifier of a SMO

Response

The identifiers can be found in various places in the response.

type record identifier	where to find	interface
recordId	about recordSchema	SRU
recordId	meta recordSchema	SRU
uploadId	about recordSchema	SRU
uploadId	meta recordSchema	SRU
uploadId	recordIdentifier in SRU response	SRU
jsonldId	about recordSchema	SRU
jsonldId	@id attribuut in jsonld recordSchema's	SRU/Jsonsearch
smoId	recordIdentifier in SRU response	SMO SRU
smoId	smoId veld in smo recordSchema	SMO SRU
smoId	schema:itemReviewed veld in jsonld recordSchema van Review	SRU/Jsonsearch

Search

The identifiers can be used as a search field within the search query.

type record identifier	search field
uploadId	about.identifier
uploadId	meta.upload.id
recordId	about.record.identifier
recordId	meta.record.id
jsonldId	about.jsonldIdentifier
jsonldId	@id
smoId	about.record.identifier
smoId	smo.smoId
smoId	schema:itemReviewed

Collection Identifier

The collection identifier is the identifier under which the connected repository within Edurep is known. This identifier can be found as a prefix in the upload identifier, but also separately in the about recordSchema. An overview of all collections can be found via a drilldown or through our collection overview.

Since the collection identifier has only a technical (and not content) value, we do not recommend searching with this field. If there is a need, there are two options: white list or black list. The whitelist explicitly indicates which collections should be searched for each search query. The blacklist specifically indicates which collections should not be searched.

When the majority of available collections are whitelisted, the search becomes unnecessarily long and will slow down the speed of the search. In that case, using a blacklist is better. Another advantage of a blacklist is that new collections are automatically searched without having to explicitly include them in the whitelist. Below is an example of a blacklist search.

/edurep/sruns: query=fiets NOT (about.repository exact anno OR about.repository exact nationaalarchief)