JiscMail Logo
Email discussion lists for the UK Education and Research communities

Help for DC-ARCHITECTURE Archives


DC-ARCHITECTURE Archives

DC-ARCHITECTURE Archives


DC-ARCHITECTURE@JISCMAIL.AC.UK


View:

Message:

[

First

|

Previous

|

Next

|

Last

]

By Topic:

[

First

|

Previous

|

Next

|

Last

]

By Author:

[

First

|

Previous

|

Next

|

Last

]

Font:

Proportional Font

LISTSERV Archives

LISTSERV Archives

DC-ARCHITECTURE Home

DC-ARCHITECTURE Home

DC-ARCHITECTURE  March 2012

DC-ARCHITECTURE March 2012

Options

Subscribe or Unsubscribe

Subscribe or Unsubscribe

Log In

Log In

Get Password

Get Password

Subject:

Re: DCAM RDF Revision revisited

From:

Thomas Baker <[log in to unmask]>

Reply-To:

DCMI Architecture Forum <[log in to unmask]>

Date:

Sun, 4 Mar 2012 22:49:22 -0500

Content-Type:

text/plain

Parts/Attachments:

Parts/Attachments

text/plain (108 lines)

On Sun, Mar 04, 2012 at 04:55:25PM -0800, Karen Coyle wrote:
> I have to admit that I am sometimes a bit confused about whether we
> are talking about DCAM or DCAP in some of this discussion. Would it
> be useful to tease those apart? Or can we clearly combine them into
> a single model? (And if they are the same, why were they two
> different things before?)

That's precisely the question I was getting at earlier in this thread (on
Tuesday).  Rephrasing...:

    The (current) DCAM Vocabulary Model [1] is grounded in RDFS.  It has:

        -- Properties,
        -- Classes, 
        -- RDF Datatypes (aka Syntax Encoding Schemes)
        -- Vocabulary Encoding Schemes (no different from SKOS Concept Schemes?).

        These are open-world semantic concepts.

    The (current) DCAM Description Set Model [1] adds the following:

        -- constructs for bounded Description Sets and Descriptions

        -- constructs for two very generic patterns for descriptive information (literals,
           URIs, and blanks), grouped in Property-Value pairs in which the value is either:

           o  Literal Value Surrogate: expressible as one RDF statement with one RDF literal

           o  Non-Literal Value Surrogate: a set of information expressible
              as multiple RDF statements (e.g., X dcam:memberOf <someVES>)

           These property-value pairs are referred to -- very confusingly, I
           believe -- as DCAM "Statements".

        These are closed-world syntactic constructs -- "slots" for holding data.

    The (current) Description Set Profile _Constraint Language_ (DC-DSP) [2] provides
    a language for building "templates" that "constrain" DCAM constructs:

        -- "template" constructs:
           Description Set (DCAM)    ->    Description Set Template (DSP)
           Description (DCAM)        ->    Description Template (DSP)
           Statement (DCAM)          ->    Statement Template (DSP)

        -- constructs for "constraining" the templates:
           Value String (DCAM)       ->    Value String Constraint (DSP)

        I think of this as a _language_ for _templating_ metadata records based
        on DCAM slots.

    The (current) notion of DC Application Profile (DCAP), as described in
    the Singapore Framework [3], is centered on a Description Set Profile -- i.e.,
    the specification of a particular set of Templates and Constraints.  For 
    example:

        -- "This profile specifies a Description Set Template
        --  ... which holds two Description Templates,
        --  ... one of which describes a foaf:Person (i.e., Resource Class Constraint)
        --  ... using a Statement Template
        --  ... that uses the property foaf:givenname (i.e., Property Constraint)
        --  ... etc ..."

        I think of a particular Description Set Profile as a particular
        template for manufacturing closed-world data validation schemas in
        particular concrete syntaxes -- a template for making cookie cutters.

    The (current) notion of a Data Format in the Singapore Framework is that of
    a closed-world data validation schema in a particular concrete syntax --
    one that intellectually matches a Description Set Profile, which is
    expressed in the Description Set Profile Constraint Language, which in turn
    is based on DCAM.
        
        The Data Format is the cookie cutter for making instance metadata
        (i.e., "records") using a particular concrete syntax -- or for testing
        whether a particular cookie (i.e., "record") _matches_ the cookie
        cutter.

Looking at the top layer of the Singapore Framework [3] as a sequence for
_designing_ metadata, the idea is to:

    -- Figure out why something needs to be described (Functional Requirements)
    -- Name the "things" that need to be described (Domain Model)
    -- Decide what properties, with what constraints, are needed for describing
       those things (Description Set Profile) -- a template for a Data Format.
    -- Create a cookie cutter (Data Format) for creating instance Records.

In the Singapore Framework, DCAM, RDFS, FRBR, Dublin Core and other RDF
vocabularies, and DCAM-in-XML or DCAM-in-Microdata guidelines provide the
support for this process -- they are "one layer below" the process outlined
above.

Perhaps there are better analogies than Cookie Cutters, such as patterns for
making dresses... or microprocessors.  The layers of terminology ("template",
"profile"...) make it hard to tell this story clearly.  And I do wonder whether
it is necessary to make these particular distinctions, or if there are simpler
ways to slice the pie.  This is, I think, the question that Karen is also
asking.

Tom

[1] http://dublincore.org/documents/abstract-model/
[2] http://dublincore.org/documents/dc-dsp/
[3] http://dublincore.org/documents/singapore-framework/



-- 
Tom Baker <[log in to unmask]>

Top of Message | Previous Page | Permalink

JISCMail Tools


RSS Feeds and Sharing


Advanced Options


Archives

April 2014
March 2014
February 2014
January 2014
November 2013
October 2013
September 2013
August 2013
July 2013
June 2013
May 2013
April 2013
March 2013
February 2013
January 2013
December 2012
November 2012
October 2012
September 2012
August 2012
July 2012
June 2012
May 2012
April 2012
March 2012
February 2012
January 2012
December 2011
November 2011
October 2011
September 2011
August 2011
July 2011
June 2011
May 2011
April 2011
March 2011
February 2011
January 2011
December 2010
November 2010
October 2010
September 2010
August 2010
July 2010
June 2010
May 2010
April 2010
March 2010
February 2010
January 2010
December 2009
November 2009
October 2009
September 2009
August 2009
July 2009
June 2009
May 2009
April 2009
March 2009
February 2009
January 2009
November 2008
October 2008
September 2008
August 2008
July 2008
June 2008
May 2008
April 2008
February 2008
January 2008
December 2007
November 2007
October 2007
September 2007
August 2007
July 2007
May 2007
April 2007
March 2007
February 2007
January 2007
December 2006
November 2006
October 2006
September 2006
August 2006
July 2006
June 2006
May 2006
April 2006
March 2006
February 2006
January 2006
December 2005
November 2005
September 2005
August 2005
July 2005
June 2005
April 2005
March 2005
February 2005
January 2005
December 2004
November 2004
October 2004
September 2004
August 2004
July 2004
June 2004
May 2004
March 2004
February 2004
January 2004
November 2003
October 2003
September 2003
August 2003
June 2003
May 2003
April 2003
March 2003
January 2003
December 2002
November 2002
October 2002
September 2002
August 2002
July 2002
June 2002
May 2002
April 2002
March 2002
February 2002
January 2002
December 2001
November 2001
October 2001
September 2001
August 2001
July 2001
June 2001
May 2001
April 2001
March 2001
February 2001
December 2000
November 2000
October 2000


WWW.JISCMAIL.AC.UK

Secured by F-Secure Anti-Virus CataList Email List Search Powered by the LISTSERV Email List Manager