Refining the Scope of Interest

This section discusses the development of an inventory of technologies using the results of an analysis of the Open Archival Information System (OAIS) Reference Model to identify information technology developments that are of potential interest for digital preservation. The research on technology developments identified the OAIS Reference Model for this purpose because it was the first, the most comprehensive, and remains the only formal expression of the roles,

functions, and entities of the digital preservation process.⁶⁷

To introduce the analysis of the OAIS functions, the seven functional groups of OAIS are briefly summarised here, highlighting the kinds of capabilities and technologies that each functional group relies upon.

Parsing the descriptions of the thirty-three functions in the OAIS Reference Model to identify references to technologies provided a means for developing a more detailed specification of technology developments for digital preservation. The analysis of OAIS functions defined an inventory of technologies that are potentially relevant to digital

preservation.

68 Ingest receives digital content in the form of Submission Information Packages (SIPs), performs quality control checking and specified protocols for receiving digital content, supplements the metadata received with the digital content as needed, and uses the digital content and metadata to generate well-formed digital objects, or Archival Information Packages (AIPs).⁶⁹ Archival Storage receives the AIPs from Ingest, securely stores the AIPS, then safeguards the AIPS through continual error checking, disaster preparedness and response, and media management and replacement.⁷⁰

67 References in this section are to the Recommendation for Space Data System Standards:

Reference Model for an Open Archival Information System (OAIS), Consultative Committee for Space Data Systems (CCSDS), CCSDS 650.0-B-1, Blue Book, January 2002. This statement reflects the status of digital preservation developments as of October 2007.

68 Section 1.3 identified the seven functional groups of OAIS in the discussion of preservation activities.

69 Ingest also manages migrations of file formats by regenerating AIPs with migrated formats, an important role that may not be made explicit or clear in digital preservation discussions. CCSDS, OAIS Reference Model, 4-5 – 4-6, 5-1 – 5-9.

70 CCSDS, OAIS Reference Model, 4-6 – 4-8.

Data Management receives and manages information about the digital content over its lifecycle to support preservation and access and is responsible for administering the

database functions for the repository.⁷¹ Administration defines and applies policies, standards, and preservation strategies for the operation of the OAIS system,

including the management of the platform.⁷² Preservation Planning monitors for relevant changes in technology and the environment, and develops, tests, and recommends standards, tools, techniques, and procedures to Administration.⁷³ Access enables and controls the use of the digital content in the OAIS in the form of Dissemination Information Packages (DIPs).⁷⁴ Common Services provides

fundamental information system support in the form of the operating system, networking controls and protocols, and system security protocols and

mechanisms.⁷⁵

The analysis included an examination of the explicit relationship between the OAIS functions and the three core digital preservation activities: to identify digital content to be preserved; to take responsibility for bringing that digital content into a sustainable environment with a digital preservation regimen

appropriate to the digital content; and to ensure that the digital content can be made available over time to authorised users.

The analysis examined the thirty-three individual OAIS functions, but the seven OAIS functional groups provide a useful structure for summarising and discussing the results.

76 OAIS specifically addresses the three core digital preservation activities. Identifying digital content to be preserved is defined in negotiations with the producer of the digital content, specified by Administration in submission agreements, and confirmed by Ingest upon receipt of the digital content.⁷⁷ Ensuring that the digital content is brought into a sustaining digital preservation context is enabled by Common Services and the controlled sequence provided by Ingest, Archival Storage, and Data Management with policies from Administration and recommendations for addressing the evolution of digital content from Preservation Planning.⁷⁸

71 CCSDS, OAIS Reference Model, 4-8 – 4-10.

72 CCSDS, OAIS Reference Model, 4-10 – 4-12.

73 CCSDS, OAIS Reference Model, 4-12 – 4-14.

74 CCSDS, OAIS Reference Model, 4-14 – 4-16.

75 CCSDS, OAIS Reference Model, 4-3 – 4-5.

76 Section 1.3 discussed the definition of digital preservation fundamentals, including these preservation activities.

77 CCSDS, OAIS Reference Model, 2-9, 4-2, and 4-10.

78 CCSDS, OAIS Reference Model, 4-17 – 4-18.

Providing digital content to authorised users is coordinated by Access, managed by Administration, supported by Data

Management, and made possible through designs recommended by Preservation Planning.⁷⁹

To begin the process of refining the scope of interest in technologies for digital preservation, the research analysed the description of each function in the OAIS Reference Model document to identify references to technologies or technology capabilities, implicit and explicit, that enable the function or upon which the function would rely. This analysis of OAIS functions descriptions identified thirty-eight types of technologies and technological functionalities that enable the OAIS functions or with which it interacts.

This examination linked the analysis of the scope of interest in technology developments to the fundamentals of digital preservation practice.

80 An objective of the analysis was to identify technologies consistently so that the results could be used

systematically to identify and track information technology developments for digital preservation.⁸¹ The resulting technology inventory of thirty-eight capabilities and technologies are listed in Figure 2-3. Some of the technologies are higher level, e.g., artificial intelligence and systems engineering, and some are lower level, such as storage capacity. Some are complex technologies, e.g., e-commerce, and some are simple, e.g., file formats. The inventory provides a specific list of types of technologies to track for digital preservation based on the analysis of OAIS functions. The list would have to be extended and updated by the digital preservation community as technology and digital preservation requirements evolve.⁸²

These are examples to illustrate the analysis of function descriptions to identify specific examples of technologies. Receive Submission is a function in Ingest. Receive Submission is the OAIS function that receives the digital content from a producer and issues a confirmation of receipt back to the producer

(messaging mechanisms). It may involve legal transfer that requires access controls.

79 CCSDS, OAIS Reference Model, 2-9 – 2-10, 3-3, 3-5, 4-2, and 4-17.

80 The full results of the analysis of each OAIS function are presented in Table 1 of Annex 1. The thirty-eight technologies are explained in Table 2 of Annex 1.

81 In an actual implementation of an OAIS-based system, the functions may be performed using automated or manual means, but the inventory of technology developments presumes that the function or functionality could be automated.

82 For example, a revision of the OAIS Reference Model is due in 2008 and that revision may affect the technology developments inventory. UKOLN, ‘OAIS Five Year Review’,

http://www.ukoln.ac.uk/repositories/digirep/index/OAIS_five_year_review (accessed 1 June 2007).

This function may require iterative communication with the producer if there are errors in or problems with the Submission Information Package.⁸³ The Receive Submission function involves storage media, file formats, and metadata. It relies upon adequate storage capacity to store the digital content, at least during the check-in process; security protocols to enforce appropriate access controls; and communication capabilities to send and receive messages. Error Checking is the function in the Archival Storage functional group of OAIS that continually

monitors and assesses stored digital content, AIPs, for indicators of degradation and potential loss.⁸⁴

Errors could indicate that storage media is failing or that the characteristics of stored file have changed since the previous check. This function relies upon the capability of hardware and software to send messages about errors, the ability of the OAIS system to store the messages in logs and to process the logs, the reliability of mechanisms to randomly check for changes in the digital content, and the ability to send and receive messages.

human computer interface Figure 2-3. Technology inventory of OAIS function descriptions.

Technologies in italics in Figure 2-3 were specifically cited in the descriptions of OAIS functions. For example, several function descriptions explicitly referred to storage media, i.e., Receive Submission, Quality Assurance, Receive Data, Manage Storage Hierarchy, Replace Media, Error Checking, Disaster Recovery, and Provide Data. Examples of technologies that were inferred from the function descriptions include references to:

83 CCSDS, OAIS Reference Model, 4-5.

84 CCSDS, OAIS Reference Model, 4-8.

• Descriptive information listed as metadata

• SIPs, AIPs, and DIPs listed as file formats and metadata to reflect the content and metadata found in all OAIS information packages

• Policies listed as policy enforcement because the references were to invoking policies

• Actions to send a confirmation receipt, send a report, receive a request listed as messaging mechanism because the underlying technology capability is sending and receiving messages

The technology inventory reflects the technologies and capabilities that were explicitly cited in or inferred from the descriptions of OAIS functions.

In addition to the technology inventory, a second outcome of the analysis of OAIS functions was a set of recurring terms that could be used as keywords to enable continual monitoring of selected technology developments. The keyword list, like the inventory of technologies, could be extended and maintained by the digital preservation community as technology evolves. Figure 2-4 presents examples of keywords for each OAIS functional group. A similar list could be developed and maintained for each OAIS function and for each item on the technology inventory for continual monitoring.

OAIS functional group Keywords

Common Services Security, networks, authentication, operating system Ingest Acquisition, selection, quality control, validation

Archival Storage Persistent storage, storage media, file formats, migration Data Management Metadata, database, access control

Administration Audit, policies, procedures

Preservation Planning Preservation strategies, longevity, persistence, standards Access Use, usability, user expectations, rights management

Figure 2-4Keywords for relevant technology developments.

Analysing the OAIS functions demonstrates an approach for refining the scope of interest in technology developments for digital preservation. Ongoing tracking of technology developments in all of the areas identified by the technology inventory would produce a large number of technology developments that might

have potential implications for digital preservation.⁸⁵

The five integrity features defined by the authors of the Preserving Digital Information report (content, fixity, reference, provenance, and context; see Section 2.5 and 2.6) provided a starting point for developing criteria to prioritise technology developments for digital preservation.

Developing a means for prioritising the resulting list of potentially relevant technology developments would enable the digital preservation community to identify, assess, and respond to the most significant technology developments.