Digital Data Preservation

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DigitalData

Preservation

Abhishek Singh Aditya Dhanraj


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What is Digital document

preservationData preservation, or more specifically,

digital data preservation, refers to the

series of managed activities necessaryto ensure continued access to digital

materials for as long as necessary.


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Need for digital preservation


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Need for digital preservation

Media issues:

urrently magnetic or optical tape and disks, some

devices !e.g., memory sticks"

#$amples include: D%&'M, D(D !optical", DA),D*) !magnetic"

+nknon lifetimes

Subject to differences in -uality or storage conditions

ut relatively short lifetimes compared to paper or

good -uality microform

/robably years rather than decades


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Digital preservation: issues

data is maintained in the repository ithout

being damaged, lost or maliciously altered0

data can be found, e$tracted and served to auser0

data can be interpreted and understood by

the user0 and

the above can be achieved in the long term.


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SHPT School of Library Science

Digital preservation process

'rganisational

Managerial and

)echnical


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'rganisational issues:

digital preservation policy 1ustification for preservation 'rganisational and financial commitment

/reservation of authentic resources and-uality control

Metadata creation 2igh%level identification of roles and

responsibilities )raining and education


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Managerial issues

preservation planning

developing strategy

taking sole responsibility for

preservation

dealing ith 3) staff or e$ternal

preservation service providers


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Methods of digital preservation

itstream opying

Durable, /ersistent Media

Standards Migration

#mulation

#ncapsulation

/reservation Metadata


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Bitstream Copying

4 or backing up

data, here you

make a duplicateof the digital object. Durable, PersistentMedia 4 here youpreserve the

physical media,

or D, on hich the

object is stored.

Migration 4 here you

copy data from one

technology to another toavoid obsolescence of

both the physical media

and the data format.

Standards 4 relies

on recogni5ed, long%

term standards over

proprietary formats.

Emulation 4 process ofreproducing softare and

hardare

environments to translate

code from one computing

environment to run

on another.

Encapsulation 4 as

part of an emulation

strategy, here objects

andmetadata are grouped

together to help decode

and render object later.

Preservation Metadata

4 describes the

softare, hardare and

re-uirements of the

digital object to use in

preserving the object.

Preservation

strategies


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)echnology emulation

/reserving the original bit%streams and application

softare0 running this on emulator programs that

mimic the behaviour of obsolete hardare

#mulators change over time haining, rehosting

#mulation (irtual Machines

&unning emulators on simplified 6virtual machines6

that can be run on a range of different platforms (irtual machines are migrated so the original bit%

streams do not have to be


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enefits:

)echni-ue already idely used, e.g. for emulatingdifferent hardare, computer games

/reserves the original bits

&educes the need for regular object transformations !but

emulators and virtual machines may themselves need to

be migrated" &etains 7look%and%feel8

May be the only approach possible here objects are

comple$ or dependent on e$ecutable code

*ess 6understanding6 of formats is needed0 little

incremental cost in keeping additional formats


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3ssues:

Which organisations have the technical

skills necessary to implement the

strategy9

/reserving 6look and feel6 may not beneeded for all objects

3t ill be difficult to know definitively

hether user e$perience has been

accurately preserved


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onclusions:

/romising family of approaches

eeds further practical application and

research


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1 BBC ne!s via "E #$%1 on !indo!s

3lye ;reymars oldeb.today emulates range of brosers


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challenges of digital

preservation )echnology obsolescence

Absence of established standards,

protocols, and proven methods forpreserving digital information

technological or economic feasibility of

operating on a mass scale


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Thank You !!

Documents

Digital Data Preservation