From "graph-based metadata":
"... a simple graph-model could be used as the basis for an abstract
metadata syntax, providing a foundation for translation between various
concrete metadata syntaxes."
Interoperability of different metadata schemas (syntaxes) is a
long-standing problem for library data, which has become worse rather than
better in recent years.
"A semantics also provides the foundation for layers of
application-specific semantics. These layers then allow metadata to be
'dumbed-down' gracefully, to whatever level is required."
The key word is "gracefully". Library cataloguers see a beauty in the
artful construction of catalogues, the interaction of its parts, the
regularity of structure, the consistency of content, etc. (akin to the
beauty of fundamental equations of physics!).
From "Son of DC":
"The notion of a graph - a set of nodes connected to other nodes - provides
a powerful abstraction for metadata interoperability. All metadata can be
viewed, or "virtualised", through this abstraction. Virtualisation leads
directly to substantial cost savings, because metadata software systems can
be 'syntax-independent' -- written once then deployed for multiple concrete
syntaxes ... In addition to cost savings through virtualisation, metadata
graphs provide additional benefits. Graphs can be easily merged with other
graphs, providing a mechanism for integrating or 'joining up' metadata from
Saving costs is very appealling to librarians, and cataloguing is costly.
"Easily" integrating or interoperating metadata from disparate sources
(including different syntaxes) is another welcome message. "Joining-up" is
another resonant phrase.
"... all aspects [of] the scholarly lifecycle can only be achieved by
joining up metadata from multiple silos, where each silo only holds a part
of the 'overall picture'."
If generalized by substituting "user information needs" for "the scholarly
lifecycle", the "part of the overall picture" message is a powerful wake-up
call for the library community.
"Dumb-down means that not all applications have to understand the details
of all metadata schemas -- specific schemas can be designed for specific
applications, without compromising interoperability at more general
This echoes a phrase being used in the library environment since the 1990s:
"Think global, act local".
The library community is aware of all of these particular issues, but lacks
confidence that resolutions are possible. Alistair's words are direct, in
constrast, say, to the W3C LLD group's final report which is necessarily
more circumspect; the contexts are significantly different, and this is not
a criticism of either approach.
On 22 February 2012 at 16:29 Thomas Baker <[log in to unmask]> wrote:
> Hi Gordon,
> On Wed, Feb 22, 2012 at 02:31:45PM +0000, Gordon Dunsire wrote:
> > btw, I wish I'd know about Alistair's stuff on the architecture wiki
> > before now - it's a great articulation of issues we've been discussing
> > the ISBD/XML Study Group, FRBR Review Group, and Joint Steering
> > for Development of RDA. But the language/terminology mis-match between
> > abstract modellers and librarians certainly prevented me from finding
> > via Google.
> There are alot of great formulations in Alistair's short paragraphs. Can
> perhaps point out the ones that particularly resonated?
> On Tue, Feb 21, 2012 at 08:51:14PM -0500, Tom Baker wrote:
> > ----------------------------------------------------------------------
> > http://dublincore.org/architecturewiki/GraphMetadata
> > Graph-based Metadata
> > This is an experimental area, discussing the feasibility and
> > value of construction of a metadata architecture on top of a
> > simple graph-model.
> > Put simply, a metadata graph describes how things are related
> > things. It doesn't go any further than that.
> > Syntactic Interoperability
> > A simple graph-model could provide an effective abstraction of
a number of
> > different metadata syntaxes, allowing metadata to be
virtualised in a
> > common, standard way.
> > In other words, a simple graph-model could be used as the basis
> > abstract metadata syntax, providing a foundation for
> > between various concrete metadata syntaxes.
> > On top of such an abstract syntax, application-specific
> > could be expressed, capturing the essential requirements of an
> > "application profile".
> > Semantic Interoperability
> > An abstract syntax based on a simple graph-model also provides
> > foundation for a precise semantics.
> > A semantics tells you how to merge graphs, i.e. how to merge
> > from different sources.
> > A semantics also provides the foundation for layers of
> > application-specific semantics. These layers then allow
metadata to be
> > "dumbed-down" gracefully, to whatever level is required.
> > --
> > Tom Baker <[log in to unmask]>
> Tom Baker <[log in to unmask]>