BitstreamFormat Renovation:DSpace Gets Real Technical Metadata
Benefits (Why Should I Care?)
• The new format identifier corrected or fixed unidentified data formats of 858 Bitstreams in DSpace@MIT. How many are mis-identified in your repository?
• Accurate MIME-types improve delivery to Web clients
• Quality preservation requires accurate data format knowledge
• Interoperability with internal and external tools relies on correct technical metadata in commonly-recognized standards
• Without automated tools, maintenance of format technical metadata is a tedious manual job for repository managers
BitstreamFormat Renovation Prototype
Data Formats
BitstreamFormat Renovation Prototype
A “Data Format” is defined as:
Technical Metadata that describes how abstract information is encoded and structured in a digital document.
“Abstract Information” refers to the actual intellectual content contained in the digital object.
Problems with Current Format Technical Metadata
• Formats are identified with arbitrary names; that hinders interoperability
• No means to collect additional format technical metadata, e.g. format specification documents.
• Identifying formats only by filename extension is imprecise and unreliable
• Current internal format model is inflexible
BitstreamFormat Renovation Prototype
Terms
• Format Registry– PRONOM– GDFR
• Identification Plugins– DROID– JHOVE
• Interoperable Format Identifiers– MIME Type– PUID (PRONOM Unique IDentifier)
BitstreamFormat Renovation Prototype
Object-Model Architecture Connected to PRONOM
BitstreamFormat Renovation Prototype
BitstreamFormat Renovation Prototype
Identification of Two BitstreamFormat Types
BitstreamFormat Renovation Prototype
The Local “DSpace” and Provisional Registries
Interface to External Registries
• Get Synonyms– Returns a list of identifiers that are bound to the same format record
• Import– Turns an external format description into a new BitstreamFormat
entry, initializing its metadata fields from the external registry
• Update– Refresh the metadata fields of a BitstreamFormat to keep up with
changes
• ConformsTo– Tests whether the format described by one identifier “conforms to”
or is a sub-type of another format
BitstreamFormat Renovation Prototype
The Bitstream Format Metadata Admin Panel
BitstreamFormat Renovation Prototype
Importing New Bitstream Formats
BitstreamFormat Renovation Prototype
Editing BitstreamFormat Metadata
BitstreamFormat Renovation Prototype
Digital Preservation Strategies
• Pluggable architecture allows for access to external identification and technical metadata tools
• Access and preservation rely on accurate format identification
• Migration / Obsolescence tools are only effective with correct and precise identification, because format versions matter
• The creation of derivatives (i.e. thumbnails or delivery versions)
via MediaFilter will also rely on accurate identification
BitstreamFormat Renovation Prototype
Interoperability Benefits
• Avoids platform lock-in
• Reliable delivery functionality
• Consistent object description semantics (ORE)
• Interoperability with digital preservation services
BitstreamFormat Renovation Prototype
Quantitative Results
• Before:– 1,020 Unidentified (0.65%)
• After:– 162 Unidentified (0.104%)
DSpace@MIT (155,000 Bitstreams)
BitstreamFormat Renovation Prototype
Related Links
http://wiki.dspace.org/index.php/BitstreamFormat_Renovation
http://www.nationalarchives.gov.uk/PRONOM/
http://droid.sourceforge.net/wiki/index.php/Introduction
https://collaborate.oclc.org/wiki/gdfr/about.html
http://www.loc.gov/standards/premis/
http://pilot.apsr.edu.au/wiki/index.php/AONS_II
http://www.ijdc.net/ijdc/article/view/53/
http://hul.harvard.edu/jhove/
http://web.mit.edu/sands/www/bfr
BitstreamFormat Renovation Prototype