besser--digital longevity 9/2/00 (12/12/99) 1 planning to maximize longevity of digital information...

Besser--Digital Longevity 9/2/00 (12/12/99) 1

Planning to Maximize Longevity of Digital Information

Howard Besser

UCLA School of Education & Information

http://www.gseis.ucla.edu/~howard


Planning to Maximize Longevity of Digital Info-

The Ecology Metaphor Why are you Managing this Information? Major Issues Facing Digital Projects The Short Life of Digital Info Important Planning Considerations Key Considerations for Imaging Projects


The Ecology Metaphor


Why are you Managing this Information?

Organizational mission & type Users Uses


Major Issues Facing Digital Projects

Dangerous Changes in Intellectual Property Law

Intellectual Access Storage Delivery Integration with other tools Interoperability


Serious Longevity Problems

_ What we know from prior widespread digital file formats

_ Images separating from their metadata_ Inaccessibility of software needed to view a

work_ Inability to even decode the file format of a

work


The Short Life of Digital Info: Digital Longevity Problems-

Disappearing Information The Viewing Problem The Scrambling Problem The Inter-relation Problem The Custodial Problem The Translation Problem


The Viewing Problem

Digital Info requires a whole infrastructure to view it

Each piece of that infrastructure is changing at an incredibly rapid rate

How can we ever hope to deal with all the permutations and combinations


The Scrambling Problem

Dangers from: Compression to ease storage & delivery Container Architecture to enhance digital

commerce


The Inter-relation Problem

-Info is increasingly inter-related to other info

-How do we make our own Info persist when it points to and integrates with Info owned by others?

-What is the boundary of a set of information (or even of a digital object)?


The Custodial Problem

In the past, much of survival was due to redundancy

How do we decide what to save? Who should save it?

Mellon-funded E-Journal Archives How should they save it?-


The Custodial Problem:How to save information?

Methods for later accessRefreshingMigrationEmulation

Issues of authenticity and evidence


The Translation Problem

Content translated into new delivery devices changes meaning– -A photo vs. a painting– -If Info is produced originally in digital form in

one encoded format, will it be the same when translated into another format?

– Behaviors


Pieces of the Solution (1/2)

-We need to insist upon clearly readable standardized ways for digital objects to self-identify their formats

-We should discourage scrambling -We need to better understand information

inter-relates to other Info, and what constitutes “boundaries” of Info objects


Pieces of the Solution (2/2)

-People and organizations wishing to make information persist need guidelines of how to go about doing it

-We need to better understand how translating from one storage or display format to another affects the meaning of a work

-We need to save the “behaviors” of a digital object, not just its “contents”


Conceptual Approaches to Digital Preservation

_ Refreshing always necessary due to volatility of physical strata– Impact on evidential value

_ Migration -- advantages & disadvantages_ Emulation -- advantages & disadvantages


To deal with Immediately-

_ Persistent IDs_ Metadata


Persistent IDs--the Problem

_ Need to separate work ID from work location

_ URNs probably won’t be ready until 2003_ Becomes a business process issue when one

organization maintains the resource and another organization references it (ie. licensed from vendors or managed by separate administrative structures)


More Persistent IDs--the Approach for today

_ PURLs_ Handles_ HTTP redirects

_ And worry about costs now and conversion costs when URNs become feasible


Data Set ManagementMore issues with referencing IDs

_ References for mirror sites_ References for back-up sites when main site

is down or bottle-necked_ References for off-site copies and archival

copies


Metadata can be the first line of defense

Can tell you– where the file is (if you can’t find the file)– where more info about the file is (if you have the

file but most other metadata has become separated)

– what the file format is– what the compression scheme is– what application program and version is needed

for the file


Structural Metadata Issues

http://sunsite.berkeley.edu/moa2


Architecture: Separating Longevity and Delivery Servers

BerkeleyLongevity

Server

BerkeleyDeliveryServer

OtherDeliveryServer

OtherDeliveryServer

OtherDeliveryServer

User

User

User

User


Groups Working onthe Big Problem

http://sunsite.Berkeley.EDU/Longevity/

CPA Task Force Getty “Time & Bits” Conference & Follow-ups- Emulation experiments in US and Europe

NEDLIB, CURL, Michigan

Mellon-funded E-Journal Archive experiments

Internet Archive Long Now


Time & Bits


Time & Bits Participants

Steward Brand Howard Besser Brian Eno Danny Hillis Peter Lyman Brewster Kahle Kevin Kelly

Jaron Lanier Doug Carlston John Heilemann Ben Davis Margaret MacLean Bruce Sterling Paul Saffo


Groups Working onPieces of the Big Problem

http://sunsite.berkeley.edu/Longevity/

Internet Archive Long Now Emulation experiments in US and Europe

NEDLIB, CURL, Michigan


Journal Archiving

_ License, don’t own; may not be even able to obtain right to make archival copy

_ Increasingly no paper back-up at all_ Usually we don’t have the important

redundancy factor_ Stanford’s LOCKSS Project (Lots of Copies

Keeps Stuff Safe) and its problems (http://lockss.stanford.edu)


Complexity of Rich Media

_ Works often have artistic nature (including video games)

_ Enormous number of elements can, at times, be very important to preserve (pacing, original artifact, elements used to construct the artifact)

_ Too complex to save every one of these aspects for every type of material

_ Importance of saving documentation


Important Planning Considerations

File Formats Choosing Interoperable Systems Adhere to standards Vendors with large installed base Refreshing and/or Migration


Key Considerations for Imaging Projects-

Users' Needs Image Quality Intellectual Property Standards Topology Tools & Processes


Key Considerations for Imaging Projects (1 of 3)

Users' Needs– Quality of Digital Surrogate– Interoperable desktop applications

Image Quality– Archival– Current online delivery



Intellectual Property Standards

– Modular and Layered Architecture– Terminology– Technical imaging information

Topology



Tools & Processes– Scanners– Compression techniques– Linking files– Workflow– Interoperable desktop applications


Some nuts-and-boltsPlanning Considerations

Think about users (and potential users), uses, and type of material/collection

Scan at the highest quality that does not exceed the likely potential users/uses/material

Do not let today’s delivery limitations influence your scanning file sizes; understand the difference between digital masters and derivative files used for delivery

Many documents which appear to be bitonal actually are better represented with greyscale scans

Include color bar and ruler in the scan

Use objective measurements to determine scanner settings (do NOT attempt to make the image good on your particular monitor or use image processing to color correct)

Don’t use lossy compression Store in a common (standardized)

file format Capture as much metadata as is

reasonably possiple (including metadata about the scanning process itself)


One Final Question:Who will collect the digital works of

today that should become the Special Collections of tomorrow?

_ web sites_ zines_ electronic journals_ listserve and email discussions_ drafts of works that later become famous


Howard Besser

UCLA School of Education & Information

http://sunsite.berkeley.edu/Longevity/ http://www.gseis.ucla.edu/~howard http://sunsite.berkeley.edu/moa2 http://lockss.stanford.edu http://www.longnow.com/10klibrary/TimeBitsDisc/ http://www.archive.org/

Planning to Maximize Longevity of Digital Information

besser--digital longevity 9/2/00 (12/12/99) 1 planning to maximize longevity of digital information...

Documents

digital longevity problems

digital objects

digital form

digital commerce slide

viewing problem digital

translation problem

work slide

custodial problem