Glossary of Terms

Candidate Glossary Entries

Access Policy:

Written statement authorized by the repository management that describes the approach to be taken by the repository for providing access to objects accessioned into the repository. The Access Policy may distinguish between different types of access rights, for example between system administrators, Designated Communities and general users.

Preservation Policy:

Written statement authorized by the repository management that describes the approach to be taken by the repository for the preservation of objects accessioned into the repository. The Preservation Policy is consistent with the Preservation Strategic Plan and has, as part of it an Access Policy.

Preservation Implementation Plan:

A written statement authorized by the management of the repository that describes the services to be offered by the repository for preserving objects accessioned into the repository in accordance with the Preservation Policy.

Preservation Strategic Plan:

A written statement authorized by the management of the repository that states the goals and objectives for achieving the mission of the repository. Preservation Strategic Plans may include long-term and short-term plans.

Procedure:

A written statement that specifies actions required to complete a service or to achieve a specific state or condition. Procedures specify how various aspects of the relevant Implementation Plans are to be fulfilled.

Practice:

Actions conducted to execute procedures. Practices are measured by logs or other evidence that record actions completed.

Producer:

The role played by those persons, or client systems, who provide the information to be preserved. This can include other OAISs or internal OAIS persons or systems. (From OAIS Reference Model)

Provider (or Submitter):

A person or system that submits a digital object to the repository. The Provider can be the Producer or an agent or representative completing the submission on behalf of the producer.

Repository Mission Statement:

A written statement authorized by the management of the repository that describes the commitment of the organization for the stewardship of digital objects in its custody.

Source: OAIS reference Model except where indicated otherwise

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

* A - - - - -

Access:

The OAIS entity that contains the services and functions which make the archival information holdings and related services visible to Consumers.

Access Aid:

A software program or document that allow Consumers to locate, analyze, and order Archival Information Packages of interest.

Access Collection:

A collection of AIPs that is defined by a Collection Description but for which there is no Packaging Information for the collection in Archival Storage.

Access Method:

A method for retrieving an Archival Information Package based on its name or identifier, which is available to authorized users.

Access Software:

A type of software that presents part of or all of the information content of an Information Object in forms understandable to humans or systems.

Accessibility:

Accessibility describes the degree to which a system is usable by as many people as possible. [Source: Wikipedia] Accessibility can also refer to hardware and software technologies that help people with disabilities to use the computer. [Source: Computer Encyclopedia] It is not to be confused with availability, interpretability, readability, understandability or usability.

Adhoc Order:

A request that is generated by a Consumer for information the OAIS has indicated is currently available.

Administration:

The OAIS entity that contains the services and functions needed to control the operation of the other OAIS functional entities on a day-to-day basis.

Archival Information Collection (AIC):

An Archival Information Package whose Content Information is an aggregation of other Archival Information Packages.

Archival Information Package (AIP):

An Information Package, consisting of the Content Information and the associated Preservation Description Information (PDI), which is preserved within an OAIS.

Archival Information Unit (AIU):

An Archival Information Package whose Content Information is not further broken down into other Content Information components, each of which has its own complete Preservation Description Information. It can be viewed as an ‘atomic’ AIP. An example of an AIU would be a table of numbers representing temperatures in a certain region with all the associated documentation describing how and where the temperatures were measured, what instruments were used to make the measurements, who made the measurements, why they were made, what processing has been performed on the measurements and who has had custody of these measurements since they were first created, how the measurements relate to other information, how the measurements can be uniquely referenced by others, etc.

Archival Storage:

The OAIS entity that contains the services and functions used for the storage and retrieval of Archival Information Packages.

Archive:

An organization that intends to preserve information for access and use by a Designated Community.

Associated Description:

The information describing the content of an Information Package from the point of view of a particular Access Aid.

Authentication:

Authentication is the act of establishing or confirming something or someone as authentic, that is, that claims made by or about the thing are true. Authenticating an object may mean confirming its provenance, whereas authenticating a person often consists of verifying their identity. [Source: Wikipedia] It is not to be confused with authorization.

Authorization:

Authorization is the right or permission to use a system resource; the process of granting access. [Source: Computer Encyclopedia] Resources include individual files or items data, computer programs, computer devices and functionality provided by computer applications. Generally this makes use of the authentication process to identify consumers. Consumers include computer users, computer programs and other devices on the computer. [Source: Wikipedia] It is not to be confused with authentication.

Availability:

Availability is the ratio of (a) the total time a system is capable of being used during a given interval to (b) the length of the interval. Note 1: An example of availability is 100/168 if the unit is capable of being used for 100 hours in a week. Note 2: Typical availability objectives are specified either in decimal fractions, such as 0.9998, or sometimes in a logarithmic unit called nines, which corresponds roughly to a number of nines following the decimal point, such as "five nines" for 0.99999 reliability. [Source: Wikipedia] It is not to be confused with accessibility, interpretability, readability, understandability or usability.

* B - - - - -

* C - - - - -

Client:

An application which exchanges information with another application (see also Consumer).

Collection Description:

A type of Package Description that is specialized to provide information about an Archival Information Collection for use by Access Aids.

Common Services:

The supporting services such as inter-process communication, name services, temporary storage allocation, exception handling, security, and directory services necessary to support the OAIS.

Consumer:

The role played by those persons, or client systems, who interact with OAIS services to find preserved information of interest and to access that information in detail. This can include other OAISs, as well as internal OAIS persons or systems.

Content Data Object:

The Data Object, that together with associated Representation Information, is the original target of preservation.

Content Information:

The set of information that is the original target of preservation. It is an Information Object comprised of its Content Data Object and its Representation Information. An example of Content Information could be a single table of numbers representing, and understandable as, temperatures, but excluding the documentation that would explain its history and origin, how it relates to other observations, etc.

Context Information:

The information .that documents the relationships of the Content Information to its environment. This includes why the Content Information was created and how it relates to other Content Information objects.

Co-operating Archives:

Those archives that have Designated Communities with related interests. They may order and ingest data from each other. At a minimum, Co-operating Archives must agree to support at least one common Submission Information Package (SIP) and Dissemination Information Package (DIP) for inter-archive requests.

* D - - - - -

Data:

A reinterpretable representation of information in a formalized manner suitable for communication, interpretation, or processing. Examples of data include a sequence of bits, a table of numbers, the characters on a page, the recording of sounds made by a person speaking, or a moon rock specimen.

Data Dictionary:

A formal repository of terms used to describe data.

Data Dissemination Session:

A delivered set of media or a single telecommunications session that provides data to a Consumer. The Data Dissemination Session format/contents is based on a data model negotiated between the OAIS and the Consumer in the Request Agreement. This data model identifies the logical constructs used by the OAIS and how they are represented on each media delivery or in the telecommunication session.

Data Management:

The OAIS entity that contains the services and functions for populating, maintaining, and accessing a wide variety of information. Some examples of this information are catalogs and inventories on what may be retrieved from Archival Storage, processing algorithms that may be run on retrieved data, Consumer access statistics, Consumer billing, Event Based Orders, security controls, and OAIS schedules, policies, and procedures.

Data Management Data:

The data created and stored in Data Management persistent storage that refer to operation of an archive. Some examples of this data are accounting data for Consumer billing and authorization, policy data, Event Based Order (subscription) data for repeating requests, preservation process history data, and statistical data for generating reports to archive management.

Data Object:

Either a Physical Object or a Digital Object.

Data Submission Session:

A delivered set of media or a single telecommunications session that provides Data to an OAIS. The Data Submission Session format/contents is based on a data model negotiated between the OAIS and the Producer in the Submission Agreement. This data model identifies the logical constructs used by the Producer and how they are represented on each media delivery or in the telecommunication session.

Derived AIP:

An AIP generated by extracting or aggregating information from one or more source AIPs.

Descriptive Information:

The set of information, consisting primarily of Package Descriptions, which is provided to Data Management to support the finding, ordering, and retrieving of OAIS information holdings by Consumers. Designated Community: An identified group of potential Consumers who should be able to understand a particular set of information. The Designated Community may be composed of multiple user communities.

Digital Migration:

The transfer of digital information, while intending to preserve it, within the OAIS. It is distinguished from transfers in general by three attributes:
  • a focus on the preservation of the full information content;
  • a perspective that the new archival implementation of the information is a replacement for the old; and
  • an understanding that full control and responsibility over all aspects of the transfer resides with the OAIS.
Digital Object: An object composed of a set of bit sequences.

Dissemination Information Package (DIP):

The Information Package, derived from one or more AIPs, received by the Consumer in response to a request to the OAIS.

* E - - - - -

Edition:

An attribute of an AIP whose information content has been increased or improved from a source AIP and is therefore a candidate to replace the source AIP.

Event Based Order:

A request that is generated by a Consumer for information that is to be delivered periodically on the basis of some event or events.

* F - - - - -

Federated Archives:

A group of archives that has agreed to provide access to their holdings via one or more common finding aids.

Finding Aid:

A type of Access Aid that allows a user to search for and identify Archival Information Packages of interest.

Fixity Information:

The information which documents the authentication mechanisms and provides authentication keys to ensure that the Content Information object has not been altered in an undocumented manner. An example is a Cyclical Redundancy Check (CRC) code for a file.

* G - - - - -

Global Community:

An extended Consumer community, in the context of Federated Archives, that accesses the holdings of several archives via one or more common Finding Aids.

* H - - - - -

* I - - - - -

Independently Understandable:

A characteristic of information that has sufficient documentation to allow the information to be understood and used by the Designated Community without having to resort to special resources not widely available, including named individuals.

Information:

Any type of knowledge that can be exchanged. In an exchange, it is represented by data. An example is a string of bits (the data) accompanied by a descriptionof how to interpret a string of bits as numbers representing temperature observations measured in degrees Celsius (the representation information).

Information Object:

A Data Object together with its Representation Information.

Information Package:

The Content Information and associated Preservation Description Information which is needed to aid in the preservation of the Content Information. The Information Package has associated Packaging Information used to delimit and identify the Content Information and Preservation Description Information.

Ingest:

The OAIS entity that contains the services and functions that accept Submission Information Packages from Producers, prepares Archival Information Packages for storage, and ensures that Archival Information Packages and their supporting Descriptive Information become established within the OAIS.

Integrity:

Integrity refers to the completeness of the digital objects and to the exclusion of unintended modifications as defined in the preservation rules. Integrity is measured in terms of the characteristics of the digital object being preserved. [Source: nestor]

Interpretability:

Interpretability refers to the capacity of being interpreted or explained. [Source: General Dictionary] To ensure interpretability […], the objects and their associated files must be comprehensively described in technical terms. [Source: nestor] It is not to be confused with accessibility, availability, readability, understandability or usability.

* J - - - - -

* K - - - - -

Knowledge Base:

A set of information, incorporated by a person or system, that allows that person or system to understand received information.

* L - - - - -

Local Community:

The original Designated Community, in the context of Federated Archives, served by an archive.

Long Term:

A period of time long enough for there to be concern about the impacts of changing technologies, including support for new media and data formats, and of a changing user community, on the information being held in a repository. This period extends into the indefinite future.

Long Term Preservation:

The act of maintaining information, in a correct and Independently Understandable form, over the Long Term.

* M - - - - -

Management:

The role played by those who set overall OAIS policy as one component in a broader policy domain.

Member Description:

An Associated Description that describes a member of a collection.

Metadata:

Data about other data.

* N - - - - -

NAAN

Name Assigning Authority Number in the ARK system.

* O - - - - -

Open Archival Information System (OAIS):

An archive, consisting of an organization of people and systems, that has accepted the responsibility to preserve information and make it available for a Designated Community. It meets a set of responsibilities, as defined in 3.1, that allows an OAIS archive to be distinguished from other uses of the term ‘archive’. The term ‘Open’ in OAIS is used to imply that this Recommendation and future related Recommendations and standards are developed in open forums, and it does not imply that access to the archive is unrestricted. Order Agreement: An agreement between the archive and the Consumer in which the physical details of the delivery, such as media type and format of Data, are specified.

Ordering Aid:

An application that assists the Consumer in discovering the cost of, and in ordering, AIPs of interest.

Overview Description:

A specialization of the Collection Description that describes the collection as a whole.

* P - - - - -

Package Description:

The information intended for use by Access Aids.

Packaging Information:

The information that is used to bind and identify the components of an Information Package. For example, it may be the ISO 9660 volume and directory information used on a CD-ROM to provide the content of several files containing Content Information and Preservation Description Information.

Physical Object:

An object (such as a moon rock, bio-specimen, microscope slide) with physically observable properties that represent information that is considered suitable for being adequately documented for preservation, distribution, and independent usage.

Preservation Description Information (PDI):

The information which is necessary for adequate preservation of the Content Information and which can be categorized as Provenance, Reference, Fixity, and Context information.

Producer:

The role played by those persons, or client systems, who provide the information to be preserved. This can include other OAISs or internal OAIS persons or systems.

Provenance Information:

The information that documents the history of the Content Information. This information tells the origin or source of the Content Information, any changes that may have taken place since it was originated, and who has had custody of it since it was originated. Examples of Provenance Information are the principal investigator who recorded the data, and the information concerning its storage, handling, and migration.

* Q - - - - -

* R - - - - -

Readability:

Readability refers to the capacity to read the storage media and the appropriate bit sequence. [Source: nestor] It is not to be confused with accessibility, availability, interpretability, understandability or usability.

Reference Information:

The information that identifies, and if necessary describes, one or more mechanisms used to provide assigned identifiers for the Content Information. It also provides identifiers that allow outside systems to refer, unambiguously, to a particular Content Information. An example of Reference Information is an ISBN.

Reference Model:

A framework for understanding significant relationships among the entities of some environment, and for the development of consistent standards or specifications supporting that environment. A reference model is based on a small number of unifying concepts and may be used as a basis for education and explaining standards to a non-specialist.

Refreshment:

A Digital Migration where the effect is to replace a media instance with a copy that is sufficiently exact that all Archival Storage hardware and software continues to run as before.

Repackaging:

A Digital Migration in which there is an alteration in the Packaging Information of the AIP.

Replication:

A Digital Migration where there is no change to the Packaging Information, the Content Information, and the PDI. The bits used to represent these Information Objects are preserved in the transfer to the same or new media instance.

Representation Information:

The information that maps a Data Object into more meaningful concepts. An example is the ASCII definition that describes how a sequence of bits (i.e., a Data Object) is mapped into a symbol. In order to keep things manageable, Representation Information can be factored in distinct types, such as Structure , Semantics and Other. The latter can include Software and Standards, among other things. This normalisation allows one, for example, to describe two sets of information which are identical, but which are held in different structures (formats), by combining the same Semantic description with different Structure descriptions.

"The Representation Information accompanying a physical object like a moon rock may give additional meaning, as a result of some analysis, to the physically observable attributes of the rock." "The Representation Information accompanying a digital object, or sequence of bits, is used to provide additional meaning. It typically maps the bits into commonly recognized data types such as character, integer, and real and into groups of these data types. It associates these with higher level meanings which can have complex inter-relationships that are also described." See: http://ssdoo.gsfc.nasa.gov/nost/isoas/us12/presentations/OAISRMTutorial/sld027.htm

Representation Information accompanying a digital object, or sequence of bits, in the form of a data bit description (structure) and a semantic description such as a data dictionary can allow the automated reading of the digital object into applications. For example, a scientific data file format could be described with and EAST data description (http://public.ccsds.org/publications/archive/644x0b2.pdf) so that the bits can be mapped to data types and groups of these data types. The individual data values or groups of values read via the EAST description can be further described by associating semantics to them such as the scientific data units a text description of what the value(s) are etc. Further knowledge management techniques can be added as semantics to describe what the values and groups of values are and form associations between them. A good example of this is an ontology for a table which would include the concepts of a table cell, row and column along with table cell, row, column and table metadata. Given all this information it is possible to automatically read the data from the file into a table object in the application code that can then be viewed or processed further without any knowledge of the underlying data file.

Representation Network:

The set of Representation Information that fully describes the meaning of a Data Object. Representation Information in digital forms needs additional Representation Information so its digital forms can be understood over the Long Term. Representation Rendering Software: A type of software that displays Representation Information of an Information Object in forms understandable to humans.

Result Set:

The set of descriptive records for those AIPs in an OAIS which match the criteria stated in a Consumer query, or other results from a search on Data Management.

Retrieval Aid:

An application that allows authorized users to retrieve the Content Information and PDI described by the Package Description.

* S - - - - -

Search Session:

A session initiated by the Consumer with the archive during which the Consumer will use the archive Finding Aids to identify and investigate potential holdings of interest.

Structure Information:

The information that imparts meaning about how other information is organized. For example, it maps bit streams to common computer types such as characters, numbers, and pixels and aggregations of those types such as character strings and arrays.

Submission Agreement:

The agreement reached between an OAIS and the Producer that specifies a data model for the Data Submission Session. This data model identifies format/contents and the logical constructs used by the Producer and how they are represented on each media delivery or in a telecommunication session.

Submission Information Package (SIP):

An Information Package that is delivered by the Producer to the OAIS for use in the construction of one or more AIPs.

* T - - - - -

Transformation:

A Digital Migration in which there is an alteration to the Content Information or PDI of an Archival Information Package. For example, changing ASCII codes to UNICODE in a text document being preserved is a Transformation.

* U - - - - -

Understandability:

Understandability is a judgment of how easy a text is to understand for a given established and characterised population. The understandability of a text is an interaction between the reader whose possible prior knowledge of aspects of the content and the text features would influence the ease with which they access the text, as well as the fixed aspects of the text itself. Presentation factors unrelated to the language of the text also affect understandability, for example choice of typeface, text size, layout and colors. [Source: Wikipedia] It is not to be confused with accessibility, availability, interpretability, readability or usability.

Unit Description:

A type of Package Description that is specialized to provide information about an Archival Information Unit for use by Access Aids.

Usability:

Usability denotes how easy something is to use. In human-computer interaction, usability refers to the elegance and clarity with which the interaction with a computer program or a web site is designed. [Source: Wikipedia] It is not to be confused with accessibility, availability, interpretability, readability or understandability.

* V - - - - -

Version:

An attribute of an AIP whose information content has undergone a transformation on a source AIP and is a candidate to replace the source AIP.

* W - - - - -

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* Y - - - - -

* Z - - - - -

-- DavidGiaretta - 31 Aug 2007

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Topic revision: r9 - 2008-09-22 - DavidGiaretta
 
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