Office formats

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Practical Experiences of the Digital Preservation
Testbed Office formats Jacqueline Slats File
Formats for Preservation, Erpanet May10-11 2004,
Vienna, Austria
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• Digital Preservation Testbed is performing
  experiments on three strategies for preserving
  records without affecting the authenticity of the
  records
• - Migration
• - XML
• - Emulation (Universal Virtual Computer)
• Is assessing their practical use for theDutch
  situation.

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• Experiments are taking place on
• text documents
• spreadsheets
• electronic mail
• databases.

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Research Questions

• Advantages of each preservation approach?
• Factors affecting each approach?
• Effectiveness of each approach?
• Basic Requirements for Preservation(context,
  content, structure, appearance, behaviour)
• Which metadata are essential for preservation?

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Experiment Process (1)

• Step 1 Definition of the process
• Step 2 Preparation for the process
• Step 3 Authenticity requirements and evaluation
  checklist
• Step 4 Design of the experiments
• Step 5 Resource specification
• Step 6 Go/no go decision

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Experiment Process (2)

• Step 7 Development of the experiment
• Step 8 Test experiment
• Step 9 Go/no go decision
• Step 10 Run experiment
• Step 11 Evaluate experiment
• Step 12 Consider results

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Testbed Team
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Digital record as a combination of ...
Hardware
Software
Computer file
Digital Record
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Basic Requirements for Preservation

• Context
• Content
• Structure
• Appearance
• Behaviour

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Basic Requirements for Preservation of text
documents Context

• Organisational context, such as name of
  organisation, business process, date, relation
  with other documents
• Preservation Log File, with information about
  original and current file formats, name and
  version of hardware, software and OS,
  preservation actions

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Basic Requirements for Preservation of text
documents Content

• All content must be preserved, including headers
  and footers, table of content, document
  properties, remarks
• Plain text must always be readable

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Basic Requirements for Preservation of text
documents Structure

• Structure of the document must be preserved, in
  order to represent the logical relations between
  the components of the document, such as the order
  of chapters, paragraphs, but also the right
  position of inserted remarks, footnotes and images

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Basic Requirements for Preservation of text
documents Appearance

• The appearance of the original and the preserved
  version do not have to be identical, but the new
  appearance may not in any way affect the meaning
  of the original record

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Basic Requirements for Preservation of text
documents Behaviour

• Description of active links must be preserved
• Active behaviour, updating the content must not
  be preserved, but prove of this behaviour driven
  content does

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Text documents (1)
Approach
Results

• Migration from an older version of an application
  to a newer version of this application
• Migration from an application to a standard
  format PDF
• Migration of old records created in one word
  processor to another (WP to Word)

• For the short term needs to be repeated every
  few years manual checking only if migration is
  automated
• PDF is suitable to represent text documents
  authentically, especially the appearance
• Met authenticity requirements only after manual
  intervention

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Text documents (2)
Approach
Results

• Conversion to XML

• XML is able to represent the context, content,
  structure and behavior of text documents
  authentically. To represent appearance an
  additional stylesheet is required.

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File format XML
Cons
Pros

• Open standard, controlled through W3C
• Platform-independent
• Self describing and human readable
• Well equipped to preserve content, context and
  structure

• Difficult to fully preserve the appearance of a
  texual document
• XML, its related standards and their use form a
  complex material much pioneering work still
  needs to be done

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File format PDF
Pros
Cons

• PDF is openly and freely published
• Platform-independent
• Widely used standard
• Well equipped to preserve content, context and
  appearance

• Adobe controls the development of PDF
• Sometimes loss of information (e.g. diacritic
  characters)
• No full-bodied ASCII basis

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Decision table for preservation of text documents


PDF alternativebackwards compatibility
P lt 10 jr
Implicit structure
P gt 10 jr
PDF
Text-document
PDF or XML alternativebackwards compatibility
P lt 10 jr
Explicit structure
PDF or XML
P gt 10 jr
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Preserved Object
Original file
XML file
PDFfile
Preserv. log file
Metadata
1..
1..
1
0..
1
1
Imagefile
DTD or schema
Style-sheet
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For further information about the
Testbed Website www.digitaleduurzaamheid.nl
e-mail testbed_at_nationaalarchief.nl