Page History

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Technische gezien komen eigenlijk alleen twee oplossingen in aanmerking voor het
beschreven probleem en de bijbehorende randvoorwaarden: URN en DOI/Handle.
Hieronder wordt geschetst hoe deze oplossingen zouden kunnen werken en wat de sterke / zwakke punten zijn van de oplossing.(Zie voor een zeer uitgebreid en volledig overzicht van verschillende benaderingen van implementatie van persistente identifiers ook: Hans-Werner Hilse and Jochen Kothe, Implementing Persistent Identifiers \[Hilse/Kothe, 2006\].)

\[Hakala, 2003\] Hakala, Juha, (NBN), _Identification of Electronic Resources_, 2003, [http://metadata-wg.mannlib.cornell.edu/forum/2003-01-29/juhahakala.ppt/]<span style="color: #0000ff"><a href="http://metadata-wg.mannlib.cornell.edu/forum/2003-01-29/juhahakala.ppt">http://metadata-wg.mannlib.cornell.edu/forum/2003-01-29/juhahakala.ppt</a></span>\\
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\[Hoogerwerf, 2006\] Hoogerwerf, Maarten, _Persistent Identification and linking of Datasets_. Student Thesis, 2006

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*Harvester* \[OAIPMH-definitie\]
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A harvester is a client application that issues OAI-PMH requests. A harvester is operated by a service provider as a means of collecting metadata from <span style="color: #0000ff">repositories</span>.
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Zie: OAI-PMH 2.0: [http://www.openarchives.org/oai/openarchivesprotocol.html#definitionsconcepts/]<span style="color: #0000ff"><a href="http://www.openarchives.org/OAI/openarchivesprotocol.html#DefinitionsConcepts">http://www.openarchives.org/OAI/openarchivesprotocol.html#DefinitionsConcepts</a></span>\\
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*Repository* \[OAIPMH-definitie\]
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A repository is a network accessible server that can process the 6 OAI-PMH requests in the manner described in this document. A repository is managed by a data provider to expose metadata to <span style="color: #0000ff">harvesters</span>. To allow various repository configurations, the OAI-PMH distinguishes between three distinct entities related to the metadata made accessible by the  OAI-PMH.
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\*resource - A resource is the object or "stuff" that metadata is "about". The nature of a   resource, whether it is physical or digital, or whether it is stored in the repository or is a constituent of another database, is outside the scope of the OAI-PMH.
\*item - An <span style="color: #0000ff">item</span> is a constituent of a repository from which metadata about a resource   can be disseminated. That metadata may be disseminated on-the-fly from the associated resource, cross-walked from some canonical form, actually stored in the   repository, etc.
\*record - A <span style="color: #0000ff">record</span> is metadata in a specific <span style="color: #0000ff">metadata format</span>. A record is returned as an   XML-encoded byte stream in response to a protocol request to disseminate a specific   metadata format from a constituent item.
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Zie: OAI-PMH 2.0: [http://www.openarchives.org/oai/openarchivesprotocol.html#definitionsconcepts/]<span style="color: #0000ff"><a href="http://www.openarchives.org/OAI/openarchivesprotocol.html#DefinitionsConcepts">http://www.openarchives.org/OAI/openarchivesprotocol.html#DefinitionsConcepts</a></span>\\
*Item* \[OAIPMH-definitie\]
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An item is a constituent of a repository from which metadata about a resource can be disseminated. An item is conceptually a container that stores or dynamically generates metadata about a single resource in multiple formats, each of which can be harvested as <span style="color: #0000ff">records</span> via the OAI-PMH. Each item has an <span style="color: #0000ff">identifier</span> that is unique within the scope of the repository of which it is a constituent.
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Zie: OAI-PMH 2.0: [http://www.openarchives.org/oai/openarchivesprotocol.html#definitionsconcepts/]<span style="color: #0000ff"><a href="http://www.openarchives.org/OAI/openarchivesprotocol.html#DefinitionsConcepts">http://www.openarchives.org/OAI/openarchivesprotocol.html#DefinitionsConcepts</a></span>\\
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*Unique Identifier* \[OAIPMH-definitie\]
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A unique identifier unambigiously identifies an item within a repository; the unique identifier is used in OAI-PMH requests for extracting metadata from the item. Items
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may contain metadata in <span style="color: #0000ff">multiple formats</span>. The unique identifier maps to the item, and all possible <span style="color: #0000ff">records</span> available from a single item share the same unique identifier.
The format of the unique identifier must correspond to that of the <span style="color: #0000ff">URI (Uniform Resource</span>
<span style="color: #0000ff">Identifier)</span> syntax. Individual communities may develop community-specific <span style="color: #0000ff">URI</span> schemes for coordinated use across repositories. The scheme component of the unique identifiers must not correspond to that of a recognized URI scheme unless the identifiers conform to that  scheme. Repositories may implement the <span style="color: #0000ff">oai-identifier</span> syntax described in the accompanying <span style="color: #0000ff">Implementation Guidelines</span> document.
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Unique identifiers play two roles in the protocol:
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1.  Response: Identifiers are returned by both the <span style="color: #0000ff">ListIdentifiers</span> and <span style="color: #0000ff">ListRecords</span> requests.
2.  Request: An identifier, in combination with a <span style="color: #0000ff">metadataPrefix</span>, is used in the <span style="color: #0000ff">GetRecord</span>
request as a means of requesting a <span style="color: #0000ff">record</span> in a specific metadata format from an item.
Note that the identifier described here is not that of a resource. The nature of a resource
identifier is outside the scope of the OAI-PMH. To facilitate access to the resource associated with harvested metadata, repositories should use an element in metadata records to establish a linkage between the record (and the identifier of its item) and the identifier (URL, URN, DOI, etc.) of the associated resource. The mandatory Dublin Core format provides the identifier  element that should be used for this purpose.
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Zie: OAI-PMH 2.0: [http://www.openarchives.org/oai/openarchivesprotocol.html#definitionsconcepts/]<span style="color: #0000ff"><a href="http://www.openarchives.org/OAI/openarchivesprotocol.html#DefinitionsConcepts">http://www.openarchives.org/OAI/openarchivesprotocol.html#DefinitionsConcepts</a></span>\\
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*Record* \[OAIPMH-definitie\]
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A record is metadata expressed in a single format. A record is returned in an XML\-
encoded byte stream in response to an OAI-PMH request for metadata from an item. A record is identified unambigiously by the combination of the <span style="color: #0000ff">unique identifier</span> of the item from which the record is available, the metadataPrefix identifying the metadata format of the record, and the <span style="color: #0000ff">datestamp</span> of the record. The XML-encoding of records is organized into the  following parts:
\*_header_ \- contains the unique identifier of the item and properties necessary for
selective harvesting. The header consists of the following parts:
o   the <span style="color: #0000ff">unique identifier</span> \- the unique identifier of an item in a repository;
o   the <span style="color: #0000ff">datestamp</span> \- the date of creation, modification or deletion of the record for   the purpose of <span style="color: #0000ff">selective harvesting</span>.
o   zero or more <span style="color: #0000ff">setSpec</span> elements - the <span style="color: #0000ff">set</span> membership of the item for the   purpose of <span style="color: #0000ff">selective harvesting</span>.
o   an optional status attribute with a value of deleted indicates the withdrawal of
availability of the specified metadata format for the item, dependent on the repository support for <span style="color: #0000ff">deletions</span>.
\*_metadata_ \- a single manifestation of the metadata from an item. The OAI-PMH   supports items with multiple manifestations (formats) of metadata. At a minimum, repositories must be able to return records with metadata expressed in the <span style="color: #0000ff">Dublin Core</span> format, without any <span style="color: #0000ff">qualification</span>. Optionally, a repository may also disseminate other formats of metadata. The specific metadata format of the record to be
disseminated is specified by means of an argument - the <span style="color: #0000ff">metadataPrefix</span> \- in the
<span style="color: #0000ff">GetRecord</span> or <span style="color: #0000ff">ListRecords</span> request that produces the record. The <span style="color: #0000ff">ListMetadataFormats</span> request  returns the list of all metadata formats available from a repository, or for a specific item (which can be specified as an argument to the <span style="color: #0000ff">ListMetadataFormats</span> request).
\*_about_ \- an optional and repeatable container to hold data about the metadata part of   the record. The contents of an about container must conform to an XML Schema.   Individual implementation communities may create XML Schema that define specific   uses for the contents of about containers. Two common uses of about containers are:
o   \_rights statements+: some repositories may find it desirable to attach terms of use   to the metadata they make available through the OAI-PMH. No specific set of   XML tags for rights expression is defined by OAI-PMH, but the about   container is provided to allow for encapsulating community-defined rights   tags.
o _provenance statements_: One suggested use of the about container is to indicate   the provenance of a metadata record, e.g. whether it has been harvested itself   and if so from which repository, and when. An XML Schema for such a   provenance container, as well as some supporting information is available   from the accompanying <span style="color: #0000ff">Implementation Guidelines</span> document.
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Zie: OAI-PMH 2.0: [http://www.openarchives.org/oai/openarchivesprotocol.html#definitionsconcepts/]<span style="color: #0000ff"><a href="http://www.openarchives.org/OAI/openarchivesprotocol.html#DefinitionsConcepts">http://www.openarchives.org/OAI/openarchivesprotocol.html#DefinitionsConcepts</a></span>\\
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*Persistent* \[OAIPMH-definitie\]
The repository maintains information about deletions with no time limit. A repository that
indicates this level of support must persistently keep track of the full history of deletions and consistently reveal the status of a deleted record over time.
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*Identifier* \[W3C-definitie\]
An identifier embodies the information required to distinguish what is being identified from all other things within its scope of identification.  Our use of the terms "identify" and "identifying" refer to this purpose of distinguishing one resource from all other resources, regardless of how that purpose is accomplished (e.g., by name, address, or context).  These terms should not be mistaken as an assumption that an identifier defines or embodies the identity of what is referenced, though that may be the case for some identifiers.  Nor should it be assumed that a system using URIs will access the resource identified: in many cases, URIs  are used to denote resources without any intention that they be accessed.  Likewise, the "one"  resource identified might not be singular in nature (e.g., a resource might be a named set or a  mapping that varies over time).
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Zie: Tim Berners-Lee, Roy T. Fielding, Larry Masinter. (January 2005). "Uniform Resource Identifier (URI): Generic Syntax". Internet Society. RFC 3986; STD 66. [http://gbiv.com/protocols/uri/rfc/rfc3986.html]<span style="color: #0000ff"><a href="http://gbiv.com/protocols/uri/rfc/rfc3986.html">http://gbiv.com/protocols/uri/rfc/rfc3986.html</a></span>

*Resource* \[W3C-definitie\]
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This specification does not limit the scope of what might be a resource; rather, the term
"resource" is used in a general sense for whatever might be identified by a URI.  Familiar
examples include an electronic document, an image, a source of information with a consistent purpose (e.g., "today's weather report for Los Angeles"), a service (e.g., an HTTP-to-SMS gateway), and a collection of other resources.  A resource is not necessarily accessible via the Internet; e.g., human beings, corporations, and bound books in a library can also be resources. Likewise, abstract concepts can be resources, such as the operators and operands of a mathematical equation, the types of a relationship (e.g., "parent" or "employee"), or numeric values (e.g., zero,one, and infinity).
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Zie: Tim Berners-Lee, Roy T. Fielding, Larry Masinter. (January 2005). "Uniform Resource Identifier (URI): Generic Syntax". Internet Society. RFC 3986; STD 66. [http://gbiv.com/protocols/uri/rfc/rfc3986.html]<span style="color: #0000ff"><a href="http://gbiv.com/protocols/uri/rfc/rfc3986.html">http://gbiv.com/protocols/uri/rfc/rfc3986.html</a></span>\\
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*URL* \[W3C-definitie\]
The term "Uniform Resource Locator" (URL) refers to the subset of URIs that, in addition to identifying a resource, provide a means of locating the resource by describing its primary access mechanism (e.g., its network "location").
Zie: Tim Berners-Lee, Roy T. Fielding, Larry Masinter. (January 2005). "Uniform Resource Identifier (URI): Generic Syntax". Internet Society. RFC 3986; STD 66. [http://gbiv.com/protocols/uri/rfc/rfc3986.html]<span style="color: #0000ff"><a href="http://gbiv.com/protocols/uri/rfc/rfc3986.html">http://gbiv.com/protocols/uri/rfc/rfc3986.html</a></span>\\
*URI* \[W3C-definitie\]
A Uniform Resource Identifier (URI) is a compact sequence of characters that identifies an abstract or physical resource. This specification defines the generic URI syntax and a process for resolving URI references that might be in relative form, along with guidelines and security considerations for the use of URIs on the Internet. The URI syntax defines a grammar that is a superset of all valid URIs, allowing an implementation to parse the common components of a URI reference without knowing the scheme-specific requirements of every possible identifier. This specification does not define a generative grammar for URIs; that task is performed by the individual specifications of each URI scheme.
The following are two example URIs and their component parts:
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foo://example.com:8042/over/there?name=ferret#nose
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