Description is the key to converting a digital artifact to a digital object – descrip- tion of three aspects: the bit-stream itself; the systems required to access the bit-stream; and the context in which the bit-stream was created and has been maintained.
From a museum curator’s point of view, objects that have become separated from information about them are worthless, their value being ‘little more than an aesthetic or curio value’ (Hebditch, 1998, p.viii). Not only must this informa- tion about the objects be actively generated and recorded, ‘the systems that exist to maintain this knowledge and to transfer it to the future’ must also be main- tained, for without them the objects become valueless (Hebditch, 1998, p.viii).
Museum objects and digital objects have many parallels, not the least of which is the need for documentation about them to remain available so that their meaning continues to be apparent in the future.
As the report of the NSF-DELOS Working Group on Digital Archiving and Preservation puts it, ‘There are two problems related to the preservation of digital entities that need generic solutions – interpretability and trustworthiness’
(2003, p.iv). Interpretability is maintained by preserving the means to access the bit-stream and make sense of it, or preserving information about it that allows us to recreate the means. This requires preserving documentation about the data formats used and about the software.
An unbroken documentation chain is considered an essential requirement for determining whether a digital object can be trusted. ‘Trustworthiness’ of the digital object is based on its authenticity and its integrity, that it is what it purports to be, and that it is complete and has not been altered or corrupted (Ross, 2002, p.7). Authenticity and integrity are considered to be ‘core require- ments’ that demand special attention if preserved digital objects are to be trusted.
The ease with which digital objects can be altered adds complexity to these requirements, as do some preservation strategies, such as migration and normal- ization (see Chapter 8) which ‘involve transformations of the original bitstream’
(NSF-DELOS Working Group on Digital Archiving and Preservation, 2003, p.6).
If we cannot be sure of the authenticity and integrity of a digital object, we may not be able to use it effectively. For example, the value of a record of a busi- ness transaction in digital form is compromised if it cannot be established that it has not been altered in any way. Figure 3.4 lists the threats to data integrity identified in the UNESCO Guidelines.
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Digital objects – more than digital artifacts 49
The challenge is to demonstrate the authenticity and integrity of digital objects.
This is where the documentation about the object becomes significant, as
‘authenticity is best protected by . . . documentation that maintains the clear identity of the material’ (UNESCO, 2003, p.24). For instance, if it can be estab- lished that a digital object has always been kept in the custody of an archive in which every change to it has been recorded (an example is changes resulting from migration of the bit-stream – the dates at which migration occurred, to which media, and so on), then we can be more secure about its integrity. Jones and Beagrie give further examples: scholars need confidence that the references they cite will remain stable, and materials used as evidence in legal situations need to demonstrate authenticity (Jones and Beagrie, 2001, p.25). Ross poses the questions ‘What are the requirements of authenticity and integrity functionality and what can be done to ensure that they are present in digital objects or in the systems that maintain them?’ He suggests that
underpinning authenticity and integrity and their preservation over time are the concepts of fixity, stabilisation, trust, and the requirements of custodians and users . . . an authentic digital object is one whose genuineness can be assumed on the basis of one or more of the following:
mode, form, state of transmission, and manner of preservation and custody (Ross, 2002, p.7).
Many of the concepts that are applied to ensure authenticity and integrity of preserved digital objects come from research and thinking among the record- keeping community, such as the outcomes of the Functional Requirements for Evidence in Recordkeeping Project at the University of Pittsburgh, and InterPARES (see Chapter 5). Gilliland-Swetland reminds us that ‘the value of an individual record is derived in part from the sequence of records within which it is located’ and that ‘it can be difficult to understand an individual record without understanding its historical, legal, procedural, and documentary context’ (Gilliland-Swetland, 2000, pp.16,18).
It is also necessary to preserve documentation about other aspects of digital objects in order to ensure their preservation, so that they can be understood in
50 Why There’s a Problem: Digital Artifacts and Digital Objects
• ‘Natural’ generation of errors that arise in digital storage systems
• Breakdown of carriers. Most carrier media have a reasonably short useable life before deteriorating to the point of unreliability for data storage
• Malicious attack, which may come from system hackers, viruses, staff or outside intruders interacting with the storage system
• Collateral damage from malicious acts such as terrorist attacks, acts of war or civil unrest affecting buildings or power supplies
• Inadvertent acts by staff or visitors such as turning off power, throwing out disks or tapes, or reformatting storage devices
• ‘Natural’ disasters such as fire, flood, or building collapse
• Business failure.
Figure 3.4 Threats to Data Integrity (From UNESCO, 2003, p.113)
the future. Chapter 2 noted the example of recovery of digital data from the Newham Museum Archaeological Service archives, where the lack of documen- tation meant that much of what was recovered was unusable for archaeological purposes, because the data made no sense without documentation. Gavan McCarthy, Director of the Australian Science and Technology Heritage Centre at the University of Melbourne, provides another example – that of databases produced by the State Electricity of Victoria in Australia. When the State Electricity Commission privatized its power generation in the 1990s, its assets were surveyed and it was discovered that about 237 databases or digital informa- tion systems had been created. These were analysed to determine ‘which ones had adequate documentation associated with them, or the information within them was intuitive, or implicit enough so that you could understand it’ and which were, therefore, worthwhile preserving. McCarthy observes that ‘of that 237, I think seven fulfilled those requirements. Only seven.’ In many cases ‘we couldn’t even figure out what the data was about. There was nobody around who could explain it.’ (Quotes come from an interview with McCarthy in 2004.)
Chapter 6 explores these issues in more detail.
Conclusion
This chapter notes three modes of digital death: instability of storage media, obsolescence of storage and access technologies, and challenges to the integrity of digital materials. The rapid obsolescence of hardware and software is, to a large extent, a result of today’s prevailing market-driven ethos, whose highly competitive nature means that ‘product obsolescence is often key to corporate survival in a competitive capitalist democracy’ (Kuny, 1998). Digital preserva- tion requires that means of addressing rapid obsolescence must be established.
(Some of these means are noted in Chapters 6, 7 and 8.) However, rapid obso- lescence is not the only threat to the preservation of digital materials imposed by the prevailing market-driven ethos. Another consequence of this ethos is that commercial imperatives seldom coincide with cultural heritage imperatives.
Creators of digital materials and other stakeholders may lose interest in their digital output (a business might close down, or a web site might cease to be maintained) with consequences for the future of these materials. Other threats include lack of awareness of stakeholders about digital preservation issues, a shortage of the skill sets needed to preserve digital materials, lack of inter- nationally agreed approaches, a shortage of practical models on which to base preservation practice, and a lack of ongoing funding to address digital preservation issues. These issues are noted further in the rest of the book.
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Conclusion 51