Fixity and Fluidity in Digital Preservation

Kent Anderson offers a provocative post in The Mirage of Fixity — Selling an Idea Before Understanding the Concept.  Anderson takes Nicholas Carr to task for an article in the Wall Street Journal bemoaning the death of textual fixity.  Here’s a quote from Carr:

Once digitized, a page of words loses its fixity. It can change every time it’s refreshed on a screen. A book page turns into something like a Web page, able to be revised endlessly after its initial uploading… [Beforehand] “typographical fixity” served as a cultural preservative. It helped to protect original documents from corruption, providing a more solid foundation for the writing of history. It established a reliable record of knowledge, aiding the spread of science.

Example of a file fixity error, by Wlef70, on Flickr

Example of a file fixity error, by Wlef70, on Flickr

To my mind, Anderson does a good job demonstrating that not only is “file fluidity” a modern benefit of the digital age, it has long existed in the form of revised texts, different editions and even different interpretations of canonical works, including the Bible. Getting to the root of textual fixity, according to Anderson, means getting extremely specific–“almost to the level of the individual artifact and its reproductions.”

In the world of digital stewardship, file fixity is a very serious matter.  It’s regarded as critical to ensure that digital files are what they purport to be, principally through using checksum algorithms to verify that the exact digital structure of a file remains unchanged as it comes into and remains in preservation custody. The technology behind file fixity is discussed in an earlier post on this blog; a good description of current preservation fixity practices is outlined in another post.

It is well and good to strive for file fixity in this context, and it is indeed “to the level of the individual artifact and its reproductions.”  The question arises about the degree of fidelity that needs to be maintained with respect to the original look, feel and experience of a digital file or body of interrelated files.  Viewing a particular set of files is dependent on a particular stack of hardware, software and contextual information, all of which will change over time.  Ensuring access to preserved files is generally assumed to eventually require: 1) migrating to another format, which means that it will need to change it in some way by keeping some of its properties and discarding others, or 2) emulating the original computing environment.

Each has advantages and disadvantages, but the main issue comes down to the importance placed on on the integrity of the original files.  Euan Cochran, in a comment on an earlier post on this blog, noted that “I think it is important to differentiate between preventable and non-preventable change. I believe that the vast majority of change in the digital world is preventable (e.g. by using emulation strategies instead of migration strategies).”  He noted that the presumed higher cost emulation works against it, even though we currently lack reliable economic models for preservation.

I wonder, however, if the larger issue is that culturally we are still struggling with the philosophical concepts of fixity and fluidity. Do we aim for the kind of substantive finality that Carr celebrates or do we embrace and accept an expanded degree of derivation–ideally documented as such–in our digital information?  Kari Kraus, in a comment on a blog post last week, put the question a different way:

[Significant properties] are designed to help us adopt preservation strategies that will ensure the longevity of some properties and not others. But if we concede that all properties are potentially significant within some contexts, at some time, for some audiences, then we are forced into a preservation stance that brooks no loss. What to do?

Ultimately I think wider social convention will determine the matter.  Until then it makes good sense to continue to explore all the options open to us for digital preservation.

Using Wayback Machine for Research

The following is a guest post by Nicholas Taylor, Information Technology Specialist for the Repository Development Group at the Library of Congress. Prompted by questions from Library of Congress staff on how to more effectively use web archives to answer research questions, I recently gave a presentation on “Using Wayback Machine for Research” (PDF). I […]

The is of the Digital Object and the is of the Artifact

Fixity is a key concept for digital preservation, a cornerstone even. As we’ve explained before, digital objects have a somewhat curious nature. Encoded in bits, you need to check to make sure that a given digital object is actually the same thing you started with. Thankfully, we have the ability to compute checksums, or cryptographic hashes. This […]

Read All About It! An Update on the National Digital Newspaper Program

Here at the Library of Congress, there are many projects underway to digitize and make available vast amounts of historic, archival material.  One such project is the National Digital Newspaper Program, providing access to millions of pages from historic newspapers (a previous blog post provides an introduction).  Deb Thomas, NDNP program coordinator here at the […]

If You Can’t Open It, You Don’t Own It

On October 17, I had the extreme pleasure of hearing Cory Doctorow at the Library for talk entitled “A Digital Shift: Libraries, Ebooks and Beyond.”  Not surprisingly, the room was packed with attentive listeners. The talk covered a wide range of topics–his love of books as physical objects and his background working in libraries and […]

Revisiting NISO’s “A Framework for Building Good Digital Collections”

Today’s guest post is by Carlos Martinez III, a Hispanic Association of Colleges and Universities intern in the Library of Congress’s Office of Strategic Initiatives. The National Information Standards Organization provides standards to help libraries, developers and publishers work together. Their report, A Framework Guidance for Building Good Digital Collections, is still as helpful to organizations today […]

My Weekend Project

I bought a new computer this summer.  I immediately copied all of my digital files from my old computer to my new one and to an external hard drive. Now I had three copies of my digital content on three different devices. Because if something happens to one of those media, I’ve got two others […]

Bits Breaking Bad: The Atlas of Digital Damages

A question popped up in the blogosphere recently.  “Where is our Atlas of Digital Damages?” asked Barbara Sierman of the National Library of the Netherlands. She pointed out the amazement that would greet evidence of physical books, safely stored, with spontaneous and glaring changes in their content or appearance.  “Panic would be huge if this […]

DAMs Vs. LAMs: It’s On!

As digital preservation and stewardship professionals, we approach digital objects from a unique perspective. We evaluate the long-term value of any particular digital object and work to develop a technical and social infrastructure that will enable us to successfully preserve the objects over time. Preserving and providing appropriate access are our primary functions, but no […]

Archivematica and the Open Source Mindset for Digital Preservation Systems

I  had the distinct pleasure of hearing about the on-going development of the free and open-source Archivematica digital preservation system twice this year. First, from Peter Van Garderen at the CurateGear conference and second from Courtney Mumma at a recent briefing on the project for staff at The Library of Congress. Peter and Courtney both […]