The other crucial point is that in this century, I suspect we'll see the mantra, if it's not digitized, it is not preserved.Here Richard Hess is talking about preserving the content. Once an item is digitized, then you have a digital file that you can use instead of the original. That digital file preserves the content of the original and is a surrogate for the original. In some cases, it might even be better than the original (e.g., enhanced audio). It is easy to make copies of those digital files, so now you can have lots of copies so that those contents stay safe (the idea behind LOCKSS).
As you know, preservation can take many forms, but geographic diversity of duplicate originals is a key to long-term survivability of records and documents. That is only effectively possible in the digital domain.
...While many of these organizations do an excellent job in preservation, with only one copy, the risks are high. The museum could be struck by lightning or we could see record-breaking rains like those that the DC area just experienced (too close to Harrisburg and Lancaster -- my Dad's home -- for comfort).
So, creating the digital files preserves the content, but then you must preserve those digital files. Many projects have been begun and completed without any thought to long-term preservation of the digital assets. Generally when we talk about preserving the digital assets, we simply talk about the concepts of refreshing and migrating the files. As simple as these ideas might be, procedures and processes must be put into place so that they are done. And that is not so easy or simple.
Using the glossary in the Western New York Regional Digitization Plan, which I worked on with a committee of WNYLRC members:
Refreshing is a technique used to preserve digital content. When files are refreshed, exact copies are made of them on newer media. This is done because of the concern that older media may have a limited shelf life (or may have already outlived its shelf life).Since refreshing is making copies of files onto new media, it actually is quite simple, but requires time and new media in order to do it. It is a task that can easily be procrastinated. However, if not done regularly, the project runs the risk of having its media get old and degrade, thus ruining the files stored on it. (If you have lots of copies, then hopefully a disaster has been mitigated.) The New York State Archives is recommending (in a yet to be published guideline) that organizations review their files every six months to determine if they need to be refreshed, rather than automatically refreshing the files on a regular schedule.
Migration is a technique used to preserve digital content. Migration entails the replacing older file formats and internal structures with newer ones. For example, a JPEG file might be migrated to a newer version of that format. The assumption is that the older version will eventually not be supported, so it s better to migrate files to the newer, supported formats.
And when do you migrate? When file formats have changed and the new formats are stable and are being widely adopted. The key is to migrate before support runs out on the old formats. We'll assume that the migrate paths will be easy, but -- of course -- we really don't know that for sure.
Since preserving digital files is something that we are still trying to get our heads around, there continues to be work in this area. Questions being asked include:
- Can we pinpoint better the "when"?
- How much does digital preservation cost?
- Must all digital files be preserved?
- Must all digital files be preserved at the same level? (Here we get into the concepts of bit-level preservation and full preservation.)
- James Currall and Peter McKinney. Investing in Value: A Perspective on Digital Preservation. D-Lib. Apr. 2006.
- Digital Preservation Management: Implementing Short-Term Strategies for Long-Term Problems. Cornell University Library, 2005.
- Digital Preservation Policy. National Library of Australia. February 2002.
- Stewart Granger. Emulation as a Digital Preservation Strategy. D-Lib Magazine. October 2000.
- Peter B. Hirtle. Digital Preservation and Copyright. Copyright & Fair Use/Stanford University Libraries. No date.
- Digital Preservation. The British Library. No date.
- Margaret Hedstrom. Digital preservation: a time bomb for Digital Libraries. 1995. (Yes, an older article, but interesting to see what has and had not changed!)
And so what about this mythical project? I would hope that they would think about digital preservation at the beginning of the project and plan for it, even if those plans are rough. I would, however, expect that they might enter into this project without really considering preservation and with the attitude that they will think about it "later." Like everyone else, then they will hope that "later" does not occur too late.
And what about preserving the originals? Since we understand how to conserve and preserve items that we find traditionally in libraries, museums and archives, I would expect that preservation of those items would not be a huge problem (especially for the collaborators of this project). The collaborators should be able to handle the work among themselves and either pay for it out of their operating budgets or get a grant specifically for preservation. In fact, as the collaborators talk about their strengths and what they can donate to the project, there might be one institution that could spearhead (or coordinate) any conservation/preservation efforts.
That's all for today. There is one more area to discuss: marketing. We'll tackle that later this week.
For the first parts of this series, read part 1, part 2, part 3, part 4, and part 5.
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