Digital age poses preservation problems

School of Information Prof. Margaret Hedstrom makes her television debut tonight on PBS. She's not the lead in the movie of the week, but she is a leading educator in a field not yet in the limelight - digital preservation.

Hedstrom, the soon-to-be author of a digital preservation book, is seen briefly on the documentary, "Into the Future: On the Preservation of Knowledge in the Electronic Age," which will air tonight at 10 p.m. on Channel 56 in Detroit.

Hedstom said she believes publicity, such as the documentary, is important in shedding light on the growing problem of protecting and retrieving information.

"People don't notice the problem of preserving information until they try to get a document and it is irretrievable," Hedstrom said.

A file can be lost many different ways. If the data is stored on magnetic tape, its shelf life is a maximum of 30 years.

Another way information is lost is when program upgrades render old files inaccessible.

"It's when people upgrade from Windows '95 to whatever comes next," said Hedstrom, citing a possible way large amounts of information could instantly be wiped out.

Mark Handel, one of Hedstrom's former students, said he has had experiences with this lack of backwards compatibility.

"Although the tape for the original database was available, there was no way to read the tape anymore, and no way to know how the data was arranged on the tape. In the end, I had to re-key the data by hand from a print-out made around 1980," said Handel, an information graduate student who works at the University's Digital Library.

The latest source of headaches for Hedstrom and others in her field is the World Wide Web. With the seemingly infinite amount of information posted, there is no clear way to make sure it is all preserved properly.

"The main problem is how to maintain online information across time - this requires a major institutional commitment of bodies and equipment," said Michael Nolte, senior research associate at the Institute for Social Research.

There is no clear solution to the problem, but researchers are exploring many possibilities.

The cheapest way to save all data is to print it out.

This method is also the least desirable because the computer version has many more options, such as creating links and changing original documents.

The second way to preserve information is to save all the data on disk or CD. While this method is more expensive, it preserves the computer version of the document.

"With CD, there is the possibility to save both the document and the program it was created on - such as a Web page and Netscape," Hedstrom said.

The best way not to lose a document is to prevent and plan, said Hedstrom. By making sure everything can easily change from one format to another, data should be retrievable.

"The most important thing is to store information in 'lowest common denominator' format," Nolte said.

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