METS Dissemination: Interfaces

1
METS Dissemination Interfaces

• METS Opening Day
• 28 October 2003
• Leslie Myrick

2
NYU Collections using METS Interfaces

• EAD Finding Aids
• Tokyo Tribunal Proceedings
• Afghanistan Digital Library
• CRL Web Archiving Project
• DRAM
• Hemispheric Institute
• REPO History Sign Project

3
Ingredients

• Tomcat Servlet Engine
• XSLServlet or SaxonServlet
• XT or Saxon Transformation Engine
• MySQL Database for generation
• Perl DBI and CGI for interface to DB

4
Why XSLT

• Relatively simple
• Open-source platform-neutral standards-based
• Official Recommendation of W3C
• It is XML

5
Free XSLT Tools Abound

• Editors emacs NoteTab Xalan .bat
• Servlet Containers Tomcat Resin
• Transformation Engines Xalan Saxon XT
• Parsers Xerces AelfredXP/Sax Crimson
• Parsing APIs DOM SAX

6
METS as a Functional Syntax

• METS designed not only for transfer and archival
  management but for giving access to navigating
  an object
• METS XSLT can create dynamic interfaces with
  links to resources and their metadata
• METS can be dumped into Oracle indexed and
  searched using context-aware queries.

7
How to Navigate a METS Document

• ID IDREF IDREFS
• Each ID must have a matching IDREF and v.v.
• To match an ID against more than one value use
  IDREFS (e.g. multiple ADMID values in METSfile
• Keys
• More flexible they make document into a
  database

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ID IDREF IDREFS

• Provide navigable relationships between files and
  their metadata in complex Schema e.g. METS
• Must be defined in Schema or DTD
• Restrictive Element can have only one ID ID
  values must be unique (e.g. authorID and artistID
  cant be same)

9
Keys the key() function

• Creates an index
• Defined in the stylesheet and not in the
  DTD/Schema
• Flexible many keys on one element one for each
  attribute.
• Any number of elements can match a given value

10
Uses for METS

• From the humble Finding Aid to

11
METS and Finding Aids

• Beyond the href pointer
• Useful for managing complex image structure
  e.g. multiple scans of multiple pages of letters
• Holistic way to present descriptive metadata
  along with inline image (all in one package)
• Also useful for presenting technical metadata
  that EAD does not yet accommodate

12
METS Pageturners

• Creates HTML page or frameset with links to
  resources
• Creates navigable relationships between resources
  in a METS file
• Creates complex time-based media synchronizationss

13
Sfquad.xml redux

• Question could XSLT mimic java in rendering
  METS
• The answer at the time no
• Dynamic frame reloading a special problem

14
N-YHS Edisto Album

• Album of 77 images from the Civil War period
• Logical structure album page - images
• Two to four images per page
• Presented with or without collapsible TOC

15
Tokyo Tribunal

• Simple nested structure jpg page views of
  Decision taken by the Tokyo Tribunal
• Collapsible TOC to unpack logical structure of
  various parts

16
Afghanistan Digital Library

• 40 books from 1871-1930 (400 eventually)
• Simple structure no chapters for the most part
• METS Web viewer PDF / CD version
• Page Images (TIFF at 600 dpi) service files at
  98-100 dpi

17
CRL Political Web Archive

• Collaboration between Stanford Cornell Texas
  NYU IA under aegis of CRL Mellon
• Sub-Saharan Africa South East Asia Latin
  America Western Europe
• Testbed 400 URLs websites from radical groups
  NGOs
• Internet Archive .arc files

18
Internet Archive .arc files

• .arc file 100 MB aggregate of harvested files
  along with HTTP headers and crawler-generated
  header for each file
• Fine as a simple SIP but basically unmanageable
  as an AIP or DIP
• At present accessed using byte offsets to grab
  content from aggregate file
• Only searchable by URL (Wayback Machine)

19
Can METS save .arc

• One solution a METS file for each website
  contained in .arc
• At collection level ur-METS file to manage the
  different versions of website on different dates
  in different .arcs
• Alternatively a METS file for each arc
  delineating content by byte offset Naah.

20
Its the Structure Silly

• Ur-METs with to versions (cf. serials
  model)
• Failure of web-archiving access models to date
  due to indexing at page level only
• Netarkivet.dk NWA Document format xml document
  for each page indexed by FAST
• Results thousands of hits and no context.