What do digital archives promise future readers, and how long should files stay readable?

"NARA is committed to preserving and maintaining access to the content of all of the born-digital records and digital surrogates in our holdings that are determined by the Archivist to have sufficient historical or other value to warrant continued preservation by the United States Government."

"NARA minimizes the number of file formats that must be actively managed by transforming files into selected formats that retain the significant properties of the original format, while retaining the original format files in low-access storage."

"NARA assigns persistent digital identifiers and records preservation metadata about each record to aid in the preservation of our digital holdings over time."

"Professionally managed preservation repositories represent digital preservation as a business, where long-term use of stored objects will result from quid pro quo transactions between object owners (or stewards) and preservation professionals."

"in exchange, repository managers provide an organizational commitment to digital preservation, make multiple copies, and monitor data, systems and obsolescence."

"Strategies such as emulation, migration and universal virtual computing are being implemented to ensure that content remains usable."

"Automation will be fundamental to archive electronic resources on a large scale, but it is highly unlikely that technology is going to make preservation cheap."

"Digital preservation is a combination of policies and workflows that dictate the active management of digital objects to ensure their continued authenticity and meaningful access over time."

"It does not take up much space."

"preserve the authenticity and integrity of the original digital objects"

"To keep these digital objects available for future users, long-term digital preservation is essential."

"It can be replicated for resilient preservation."

"mitigate the impact of hardware obsolescence and software ephemerality"

"Obsolescence is one of the unending battles that digital preservationists fight. File formats are continually updated, hardware consistently replaced, and software abandoned. One common strategy to combat obsolescence is to migrate older digital objects into new formats."

"But this blissful outlook may not comport with the reality of digital information preservation and interpretation."

"Le memorie ottiche vengono oggi ampiamente utilizzate per la conservazione nel tempo dei documenti digitali, soprattutto nel caso di archivi digitali prodotti da singoli individui, famiglie o organizzazioni di dimensioni medio-piccole."

"Tutte le memorie di massa finora prodotte si caratterizzano per la capacità di immagazzinare una determinata quantità di documenti per un tempo più o meno lungo ma sicuramente non illimitato"

"This invention teaches a methodology and an optical apparatus that provides long-term, archival storage using a"

"non fanno eccezione le memorie ottiche, che sono anch'esse intrinsecamente fragili"

"L’affidabilità delle memorie ottiche dipende da molti fattori (si veda la Figura 5), alcuni dei quali sono controllabili dagli ut enti, altri no"

"These media are fragile and it is important to know precisely how to manage them and which precautions should be taken in order to get reasonable assurance on their ability to preserve documents."

"Um den Verlust von Daten durch die Alterung von Datenträgern zu verhindern, müssen die Daten regelmäßig innerhalb der garantierten Datensicherheitsdauer eines Mediums auf neue Datenträger kopiert werden."

"Uwe Borghoff and his coauthors address the problem of storing, reading, and using digital data for periods longer than 50 years."

"Daher liegt der Schwerpunkt bei der Langzeitarchivierung digitaler Daten nicht mehr auf der Erhaltung des Mediums, sondern auf dem rechtzeitigen Kopieren vor dem Datenverlust."

"A system and method for storing documents in human and machine readable format."

"PDF/A ist ein Dateiformat zur Langzeitarchivierung digitaler Dokumente"

"The book examines the problem of storing, reading and using digital documents for periods longer than 50 years."

"Die Wahrscheinlichkeit, dass es in einigen Jahren noch Systeme und Programme gibt, die solche Daten lesen können, ist somit deutlich höher."

"garantiert das richtige Erscheinungsbild des Dokuments für eine Langzeitarchivierung."

"While we are rapidly advancing from vulnerable physical solutions to superior, digital media, preserving and using data over the long term involves complicated research challenges and organization efforts."

"Die hohen Kosten, die durch diese Pflege der Datenbestände entstehen, haben allerdings zur Folge, dass nur die wichtigsten Daten derart konserviert werden können."

"Nicht erlaubt sind Referenzen auf Ressourcen, die nicht in der Datei enthalten sind. Alle verwendeten Bilder und Schriftarten (die Begrenzung auf die verwendeten Zeichen ist erlaubt) müssen in der PDF-Datei enthalten sein."