Page 49 - Building Digital Libraries

CHAPTER 3

Nonetheless, as chapter 4 explains, migrating resources to an archival
format as they are incorporated into the collection is usually the most
practical approach. By supporting only a small number of formats chosen
for their archival qualities, libraries can significantly reduce the likelihood
of information loss while dramatically simplifying future migrations. Any
digital object that is kept long enough will require either a transformation
or the development of an emulation environment which only moves these
same problems to the emulator.
This process sounds straightforward, but it’s sometimes difficult to
implement. Consider a simple example in which a main document is a table
of contents with links to component subdivisions. These subdivisions also
contain dependencies (images, stylesheets, etc.) as well as links to support-
ing documents that may or may not be in HTML. If, for instance, the docu-
ment is within a page containing global navigation links, then instructing
the software to make copies of everything down to a depth of three links
could result in the retrieval of many hundreds of files. Some of these may
be in proprietary formats that will be unreadable in a few years. Other
pages may “talk” to live services that cannot be archived or even intention-
ally designed, so they cannot be copied easily. Likewise, if the original site
encapsulated the entire resource or it uses Adobe Flash or other proprietary
technologies to create navigational elements or other critical aspects, some
features in the stored version of the resource may not work as desired.

Kick the Can down the Road
Ignoring the problem by assuming that technological advances will later
resolve problems is the riskiest strategy of all. Historically, libraries do not
have a good record of fixing issues that were unresolved during technology
transitions. For example, when libraries converted from card to online cata-
logs, many cards at large libraries were not converted for a variety of reasons,
so these resources were not findable in the online catalog. Not surprisingly,
the labor that couldn’t be found to transfer them to the online environment
during the initial conversion also couldn’t be found years later when other
priorities had emerged. Additionally, the important contextual knowledge
needed to successfully transition may be lost over time. Most librarians
have not used a card catalog since the 1990s, and it’s safe to say that only
a minuscule percentage of the cards that remain unconverted ever will be.
Likewise, few computer, audio, or video materials ever get converted, so
they become unusable as the hardware and software necessary to use them
becomes unavailable. It is unlikely that libraries will suddenly acquire the
considerable additional staff and money needed to identify all materials
in problematic formats and take the action that is necessary to make them
usable—especially since many libraries already struggle to meet current
demands. For this reason, hoping that some unspecified future develop-
ment will solve problems is not a realistic preservation and access strategy.
To prevent the loss of resources, it is highly recommended that repository

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