[x]Blackmoor Vituperative

Wednesday, 2005-12-07

Preserving digital information

Filed under: Society,Technology — bblackmoor @ 10:26

It took two centuries to fill the U.S. Library of Congress in Washington, D.C., with more than 29 million books and periodicals, 2.7 million recordings, 12 million photographs, 4.8 million maps, and 57 million manuscripts. Today it takes about 15 minutes for the world to churn out an equivalent amount of new digital information. It does so about 100 times every day, for a grand total of five exabytes annually. That’s an amount equal to all the words ever spoken by humans, according to Roy Williams, who heads the Center for Advanced Computing Research at the California Institute of Technology, in Pasadena.

While this stunning proliferation of information underscores the ease with which we can create digital data, our capacity to make all these bits accessible in 200 or even 20 years remains a work in progress.

[ . . . ]

Like most difficult challenges, data preservation is really a mix of the simple and the complex challenges. At one end of the preservation continuum is a simple item, like an ASCII text document. Preserve the data by keeping the file on current media and provide some way to view it and you’re pretty much done. We’ll call this the “save the bits” approach.

At the other end lie the harder cases, like these:

A compiled software program written in a custom-built programming language for which neither the language documentation nor the compiler has survived.

A complex geospatial data set developed for the U.S. Geological Survey in a proprietary system made by a company that went out of business 20 years ago.

A Hollywood movie created with state-of-the-art encryption to prevent piracy, for which the decryption keys were lost.

For these three items, we don’t hold out much hope of being able to preserve the content forever. For the software program and the geospatial data set, the digital archeologists of the future probably won’t have enough information about how the software and data set were created or the language they were created in—no Rosetta Stone, as it were, to translate the bits from lost languages to modern ones.

As for that encrypted movie, our archeologists might have read old reviews that raved about the special effects in Sin City, but this cinematic achievement will remain locked away until someone pays a lot of money to a master of ancient cryptology to crack the key.

Fortunately, many content types fall between these difficult cases and ASCII text. Usually, saving the bits using standard, well-documented data, video, and image formats, such as XML, MPEG, and TIFF, gets you halfway to an enduring digital archive. Put another way, the goal is to avoid formats that require proprietary software, such as AutoCAD or QuarkXPress, to play or render the data.

(from Spectrum Online, Eternal Bits: How can we preserve digital files and save our collective memory?)

Go read the whole article. It’s interesting stuff.