Kort introduktion til OAIS

1
Kort introduktion til OAIS

• Open
• Archival
• Information
• System

2
Program

• DEL 1
• OAIS
• Arkivbegrebet
• Informationsbegrebet
• Processerne
• Relaterede standarder

3
Historie

• NASA National Space Science Data Center er NASAs
  første digitale arkiv siden 1966
• Consultative Committee for Space Data Systems
  (CCSDS) har deltaget i ISO-arbejde siden 1990
• Blue book fra CCSDS i 2002
• Nu en CCSDS Recommendation og en ISO Standard

4
OAIS

• DEKLARATION
• ------------
• Informationsbegreb 40
• Procesbeskrivelser 40
• Interfaces 10
• Diverse fyldstoffer 10

5
En Reference model

• Abstrakt top-down
• Forstå sammenhænge arkivarer, ledere, brugere
• Rammemodel for yderligere standardisering
• Fokus på elektroniske arkivalier, men også
  ikke-elektroniske

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Hvem bruger det?

• Alle
• Digitale biblioteker
• Papirarkiver
• Videnskabelige datacentre

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Hvad er et Arkiv?

• OAIS Et arkivs hovedopgave er at bevare en
  samling information og gøre denne tilgængelig i
  en forståelig og brugbar form for et udpeget
  Designated Community (udpeget målgruppe ?)

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Model View of an OAIS Environment

• Producer is the role played by those persons, or
  client systems, who provide the information to be
  preserved
• Management is the role played by those who set
  overall OAIS policy as one component in a broader
  policy domain
• Consumer is the role played by those persons, or
  client systems, who interact with OAIS services
  to find and acquire preserved information of
  interest

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Open Archival Information SystemSix Functional
Entities
Preservation Planning
P R O D U C E R
C O N S U M E R
Data Management
queries
result sets
SIP
Ingest
Access
orders
Archival Storage
DIP
Administration
MANAGEMENT
SIP Submission Information Package
AIP Archival Information Package
DIP Dissemination Information Package
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OAIS Information Definition

• Information is always expressed (i.e.,
  represented) by some type of data
• Data interpreted using its Representation
  Information yields Information
• Information Object preservation requires clear
  identification and understanding of the Data
  Object and its associated Representation
  Information

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Information Package Definition
Preservation Description Information
Content Information

• An Information Package is a conceptual container
  holding two types of information
• Content Information
• Preservation Description Information (PDI)

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Information Object
Information Object
1
Interpreted using
1
Data Object
Representation Information
Interpreted using
Physical Object
Digital Object
1
Bit Sequence
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Recursive Nature ofRepresentation Information
Interpreted using

• Structure Information
• Semantic Information
• Other Representation Information

Representation Information
1
1

Other Representation Information

Semantic Information
Structure Information



adds meaning to
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Types of Information Used in OAIS
Information Object
. . .
Packaging Information
Preservation Description Information
Descriptive Information
Content Information
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Content Information

• The information which is the primary object of
  preservation
• An instance of Content Information is the
  information that an archive is tasked to
  preserve.
• Deciding what is the Content Information may not
  be obvious and may need to be negotiated with the
  Producer
• The Data Object in the Content Information may be
  either a Digital Object or a Physical Object
  (e.g., a physical sample, microfilm)

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Preservation Description Information

• Provenance Information
• Describes the source of Content Information, who
  has had custody of it, what is its history
• Context Information
• Describes how the Content Information relates to
  other information outside the Information Package
• Reference Information
• Provides one or more identifiers, or systems of
  identifiers, by which the Content Information may
  be uniquely identified
• Fixity Information
• Protects the Content Information from
  undocumented alteration

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PDI Examples
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Descriptive Information

• Contain the data that serves as the input to
  documents or applications called Access Aids.
• Access Aids can be used by a consumer to locate,
  analyze, retrieve, or order information from the
  OAIS.

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Packaging Information

• Information which, either actually or logically,
  binds and relates the components of the package
  into an identifiable entity on specific media
• Examples of Packaging Information include tape
  marks, directory structures and filenames

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OAIS Archival Information Package
Archival Information Package (AIP)
Packaging Information
Package Description
delimited by
derived from
e.g., How to find Content information and PDI
on some medium
e.g., Information supporting customer searches
for AIP
Preservation Description Information (PDI)
Content Information
further described by
e.g., Hardcopy document Document as an
electronic file together with its format
description Scientific data set consisting
of image file, text file, and format
descriptions file describing the other files
e.g., How the Content Information came into
being, who has held it, how it relates to
other information, and how its integrity is
assured
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AIP Types

• Archival Information Unit (AIU) contains a single
  Data Object as the Content Object
• Archival Information Collection (AIC) contains
  multiple AIPs in its Content Object
• Each member of an AIC is an AIP containing
  Content Information and PDI
• The AIC contains unique PDI on the collection
  process

Archival Information Package
Archival Information Unit
Archival Information Collection
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Package Descriptions and Access Aids

• Package Descriptions are needed by an OAIS to
  provide visibility and access to the OAIS
  holdings
• Package Descriptions contain 1 or more Associated
  Descriptions which describe the AIP Content
  Information from the point of view of a single
  Access Aid
• Some example of Access Aids Include
• Finding Aids - assist the consumer in locating
  information of interest
• Ordering Aids - allow the consumer to discover
  the cost of and order AIUs of interest
• Retrieval Aids - enable authorized users to
  retrieve the AIU described by the Unit Descriptor
  from Archival Storage

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Information Model Summary

• Presented a model of information objects as
  containing data objects and representation
  objects
• Classified information required for Long-term
  archiving into 4 classes Content Information,
  PDI, Packaging Information and Descriptive
  Information
• Described how these classes would be aggregated
  and related in an AIP to fully describe an
  instance of Content Information
• Presented information needed for Access, in
  addition to that needed for Long-term
  Preservation
• Put the Access oriented structures in the context
  of the other data needed to operate an OAIS

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Detailed Models

• Functional View

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General Principles

• Highlight the major functional areas important to
  digital archiving
• Use functional decomposition to clarify the range
  of functionality that might be encountered
• Don't decompose beyond two levels to avoid
  becoming too implementation dependent
• Provide a useful set of terms and concepts
• Do not imply that all archives need to implement
  all the sub-functions
• Identify some common services which are likely to
  be needed, and are assumed to be available, as
  underlying support

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Open Archival Information SystemSix Functional
Entities
Preservation Planning
P R O D U C E R
C O N S U M E R
Data Management
queries
result sets
SIP
Ingest
Access
orders
Archival Storage
DIP
Administration
MANAGEMENT
SIP Submission Information Package
AIP Archival Information Package
DIP Dissemination Information Package
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Functional Entities In An OAIS

• Ingest This entity provides the services and
  functions to accept Submission Information
  Packages (SIPs) from Producers and prepare the
  contents for storage and management within the
  archive
• Archival Storage This entity provides the
  services and functions for the storage,
  maintenance and retrieval of Archival Information
  Packages
• Data Management This entity provides the
  services and functions for populating,
  maintaining, and accessing both descriptive
  information which identifies and documents
  archive holdings and internal archive
  administrative data.
• Administration This entity manages the overall
  operation of the archive system
• Preservation Planning This entity monitors the
  environment of the OAIS and provides
  recommendations to ensure that the information
  stored in the OAIS remain accessible to the
  Designated User Community over the long term even
  if the original computing environment becomes
  obsolete.
• Access This entity supports consumers in
  determining the existence, description, location
  and availability of information stored in the
  OAIS and allowing consumers to request and
  receive information products

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Ingest Data Flow Diagram
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Digital Migration Approaches

• Four primary types of digital migration in
  response to motivators, ordered by increasing
  risk of information loss
• Refreshment
• Media replacement with no bit changes
• Replication
• No change to Packaging Information or Content
  Information bits
• Repackaging
• Some bit changes in Packaging Information
• Transformation
• Reversible Bit changes in Content Information
  are reversible by an algorithm
• Non-reversible Bit changes in Content
  Information are not reversible by an algorithm

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Relaterede standarder(Generelt)

• International Council on Archives Handbook No.
  7, 1988 Dictionary of Archival Terminology
  English and French og 5 andre sprog
• På vej fra Research Libraries Group (RLG)
  Certificeringskrav for arkiver

36
Schema for metadata

• For biblioteker METS, MARC, MODS, MIX, TEI, EAD,
  ONIX
• For arkiver OAI-MARC m.fl., men
• Mange er extensible
• Ingen er rigtig slået igennem

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Relaterede standarder(Representation Information)

• EAST ISO standard for databeskrivelse
  (syntaktisk beskrivelse)
• Data Entity Dictionary Specification Language
  (DEDSL) Abstract Syntax (semantisk beskrivelse)
• ISO-standarder fra Technical Committee (TC) 211
  Referencemodel for geo-data

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Relaterede standarder(Ingest)

• CCSDS, 2004 Producer-Archive Interface
  Methodology Abstract Standard
• På vej fra CCSDS XML-baserede SIPer

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Mulige fordele ved OAIS

• En anerkendt Best Practice for arkiver
• Lettere at kommunikere internationalt
• Lettere at kommunikere med ikke-arkivpersonale

40
Idéer 1

• Tilpasse sprogbrug og tankegang til OAIS så vi
  bedre kan kommunikere og i øvrigt støtte os til
  OAIS informationsbegreb og processer.
• Tilpasse vores danske begrebsapparat til OAIS.

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Idéer 2

• Justere vores informationsbegreb og
• Systematisk udpege målgruppen for nye
  afleveringer
• Lade målgruppen danne grundlag for krav til
  Representation Information og Preservation
  Description Information (kontekst) i hvert
  enkelt tilfælde
• Gruppere metadata ifølge OAIS

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Idéer 3

• Få commitment til OAIS fra hele RA
• Et OAIS arkiv skal have custody over hele
  arkivaliet dette inkluderer f.eks.
  søgebeskrivelsen i DAISY

43
Idéer 4

• Gennemgå vores processer i forhold til OAIS og
  Producer-Archive Interface Methodology Abstract
  Standard (PAIMAS ? ) så vi bliver bekræftet i
  at vi har tænkt på det hele.

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Idéer 5

• Overveje at indgå i et arkivsamarbejde
• Fælles søgemidler (på tværs af arkiver)
• Fælles Archival Storage (bevaringsdel) fælles
  digitalt bevaringscenter
• Fælles afleveringsformat og/eller
  udleveringsformat