UNDERSTANDING THE DVD LONGEVITY PROBLEM

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CONTROLS USDED IN THE NIST/LC OPTICAL DISC LONGEVITY STUDY:

QUALITY CONTROL TESTING CONDITIONS which included

Testing effects of only 2 aging factors

FINDINGS:

The Statistical Model Used showed a high probability of data longevity on the 5 brands of recordable DVD disc to be statistically as high as 45 years (Eyring Statiscical Years) -- only under the "Quality Control Testing Conditions" above.

REACTIONS TO THE NIST/LC STUDY:

REJECTED THE USE OF RECORDABLE CD/DVD DISCS FOR ARCHIVE PURPOSES.

ACTIONS SPEAK LOUDER THAN STATISTICS:

September 2007: The NIST / Library of Congress released the Final Report on the Optical Disc Longevity Study.

October 2007: Less that one month later, the National Archives and Records Administration (NARA) banned the use of recordable optical disc in NARA Departments stating (quotes from newsletter):

The statement above was published as part of NARA's internal newsletter to their own departments.

National Archives: Current Public Advisory:

Recordable (DVD) optical media have widely varying life expectancies. It is not entirely uncommon for some discs to become unreadable in less than 1 year. Relying on recordable discs to last for generations is probably not viable.   

SOURCE: http://www.archives.gov/preservation/formats/video-condition-assessment.html     

Burned (recordable CD-R, DVD-R, BD-R) discs make use of an organic dye layer in order to record data and are typically less reliable because this dye is more susceptible to degradation over time. Recordable CDs, Blu-Rays, and DVDs have proven to be fairly unstable over time, and are deemed a bad choice for long-term preservation.

Source: http://www.archives.gov/preservation/formats/video-important-characteristics.html

MORE SUPPORTING EVIDENCE:

The Relative Stabilities of Optical Disc Formats by Joe Iraci
published in
RESTAURATOR: International Journal for the Preservation of Library and Archive Material Volume 26 - Number 2 - 2005
http://www.uni-muenster.de/Forum-Bestandserhaltung/downloads/iraci.pdf

FINDINGS of RESTAURATOR Report:

The Relative Stabilities of Optical Disc Formats by Joe Iraci
(which I call, "The German / International Study")

Many types and brands were tested, however summary of ONLY DVD-R disc follows:

DVD-R DISC RESULTS:

DVD-RW DISC RESULTS: 100% of all CD/DVD RW type discs failed -- "dead as a hammer".

THE METHOD OF TESTING: "Off-the-shelf" discs were subjected to Eyring Aging Model.

IMPORTANT NOTICE: The Iraci Study specifically did NOT express aging in terms of years -- stating that it was inappropriate to attempt to do so. This is a another major difference bettween the Iraci study and the NIST/LC Study.

THE BIG DIFFERENCE BETWEEN THE 2 STUDIES:

The Method of Testing!

SUGGESTED READING: Lies, Darn Lies, and Statistics