OAIPMH

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OAI-PMH

• The Open Archives Initiative Protocol for
  Metadata Harvesting

Presenter Knud Möller Friday, 30.07.2004
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Content

• Basic idea behind OAI-PMH
• Architectural Overview
• Repositories and Harvesters
• Resources, Items and Records
• Internal Record Format
• Sets
• Selective Harvesting
• Response Format
• Command Overview

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Basic idea behind OAI-PMH

• provide a standard protocol for the harvesting/
  querying of metadata about any kind of resource -
  What kind of resources can you provide and what
  are their properties?
• OAI-PMH is only the protocol, needs to be
  implemented
• some implementations exist
• Emblem Project Utrecht
• http//emblems.let.uu.nl/emblems/html/techoai.htm
  l
• Virginia Tech (VTOAI)
• http//www.dlib.vt.edu/projects/OAI/software/vtoa
  i/vtoai.html

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Architectural Overview Repositories and
Harvesters
Harvester
Harvester
Repository
Harvester
Harvester
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Architectural Overview Repositories and
Harvesters
Harvester
Harvester
Repository
Harvester
Harvester
Harvesters issue OAI-PMH requests for metadata
via HTTP.
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Architectural Overview Repositories and
Harvesters
Harvester
Harvester
Repository
Harvester
Harvester
Harvesters issue OAI-PMH requests for metadata
via HTTP. A Repository processes the OAI-PMH
requests and has to implement the protocol.
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Architectural Overview Resources, Items and
Records
Anything - physical artifact, a digital
resource, a concept, etc. Whatever the metadata
is about.
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Architectural Overview Resources, Items and
Records
Representation of resource in repository. Can
disseminate metadata in various formats. Must
always provide Dublin Core. Has unique
identifier.
Item
oaiarXiv.orgcs/0112017
Anything - physical artifact, a digital
resource, a concept, etc. Whatever the metadata
is about.
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Architectural Overview Resources, Items and
Records
XML-encoded byte stream of actual metadata.
Representation of resource in repository. Can
disseminate metadata in various formats. Must
always provide Dublin Core. Has unique
identifier.
Item
oaiarXiv.orgcs/0112017
Anything - physical artifact, a digital
resource, a concept, etc. Whatever the metadata
is about.
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Internal Record Format I
ltrecordgt ltheadergt lt!-- blabla --gt
lt/headergt ltmetadatagt lt!-- blabla --gt
lt/metadatagt ltaboutgt lt!-- blabla
--gt lt/aboutgt lt/recordgt
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Internal Record Format I
ltrecordgt ltheadergt lt!-- blabla --gt
lt/headergt ltmetadatagt lt!-- blabla --gt
lt/metadatagt ltaboutgt lt!-- blabla
--gt lt/aboutgt lt/recordgt
ltheadergt ltidentifiergtoaiarXiv.orgcs/0112017lt
/identifiergt ltdatestampgt2002-02-28lt/datestampgt
ltsetSpecgtcslt/setSpecgt ltsetSpecgtmathlt/setS
pecgt lt/headergt
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Internal Record Format II
ltmetadatagt ltoai_dcdc
xmlnsoai_dc"http//www.openarchives.org/OAI/2.0/
oai_dc/" xmlnsdc"http//purl.org/dc/elem
ents/1.1/" xmlnsxsi"http//www.w3.org/20
01/XMLSchema-instance xsischemaLocation
"http//www.openarchives.org/OAI/2.0/o
ai_dc/ http//www.openarchives.org/OAI
/2.0/oai_dc.xsd"gt ltdctitlegtUsing
Structural Metadata to Localize Experience
of Digital Contentlt/dctitlegt
ltdccreatorgtDushay, Naomilt/dccreatorgt
ltdcsubjectgtDigital Librarieslt/dcsubjectgt
ltdcdescriptiongtWith the increasing ..bla.. to
particular communities of users.
lt/dcdescriptiongt ltdcdategt2001-12-14lt/dc
dategt ltdctypegte-printlt/dctypegt
ltdcidentifiergt http//arXiv.org/abs/c
s/0112017 lt/dcidentifiergt
lt/oai_dcdcgt lt/metadatagt
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Internal Record Format III
ltaboutgt ltprovenance
xmlns"http//www.openarchives.org/OAI/2.0/provena
nce" xmlnsxsi"http//www.w3.org/2001/XML
Schema-instance" xsischemaLocation
"http//www.openarchives.org/OAI/2.0/proven
ance http//www.openarchives.org/OAI/
2.0/provenance.xsd"gt ltoriginDescription
harvestDate"2002-02-02T141002Z"
altered"true"gt ltbaseURLgthttp//the.oa
.orglt/baseURLgt ltidentifiergtoair2.org
klik001lt/identifiergt
ltdatestampgt2002-01-01lt/datestampgt
ltmetadataNamespacegt
http//www.openarchives.org/OAI/2.0/oai_dc/
lt/metadataNamespacegt
lt/originDescriptiongt lt/provenancegt lt/aboutgt
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Sets

• Items can be organized into sets.
• Sets can either be organized flat or
  hierarchically.

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Selective Harvesting

• Harvesters can specify some constraints on which
  items they are interested in
• Regarding datestamps
• only items that where created, modified or
  deleted (optional) in a certain time period
• Regarding sets
• only items that belong to a specific set (or any
  of its subsets)

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Response Format
lt?xml version"1.0" encoding"UTF-8" ?gt
ltOAI-PMH xmlns"http//www.openarchives.org/OAI/2.
0/ xmlnsxsi"http//www.w3.org/2001/XMLS
chema-instance xsischemaLocation
"http//www.openarchives.org/OAI/2.0/
http//www.openarchives.org/OAI/2.0/OAI-PMH
.xsd"gt ltresponseDategt2002-05-01T192030Zlt
/responseDategt ltrequest verb"GetRecord"
identifier"oaiarXiv.orghep-th/9901
001 metadataPrefix"oai_dc"gt
http//an.oa.org/OAI-script
lt/requestgt ltGetRecordgt
ltrecordgt...lt/recordgt lt/GetRecordgt lt/OAI-PMHgt
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Command Overview I

• GetRecord get a specific record, must specify
  items URI and metadata prefix
• Identify retrieve information about a repository
  (name, protocol version, supports deletion, ...)
• ListRecords get either all records or a subset,
  must specify metadata prefix
• ListIdentifiers like ListRecords, but retrieves
  only headers

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Command Overview II

• ListMetadataFormats lists the available metadata
  formats of a repository
• ListSets returns the set structure of a
  repository

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References

• OAI-PMH specification http//www.openarchives.org
  /OAI/2.0/openarchivesprotocol.htm

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Thanks and goodbye!