Implicit Library Classification Schemes

[Len Gallagher <LGallagher@nist.gov>]

External Classification folks,

Here's another use case that I think should be supported by whatever method 
we choose for identifying and using external classification schemes.

Copied below are examples of Library Classifications as used by the NIST 
library. The first line of each entry is a combination of "classification 
by subject" and "date" and "unique identifier".

--------------------------------------------------------------
TA357.5 .V56 P69 1991
Boundary integral and singularity methods for linearized viscous flow / C. 
Pozrikidis.

QA484 .A7513 2001 CD-ROM
Pi-unleashed / Jorg Arndt, Christoph Haenel ; translated from the German by 
Catriona and David Lischka.

QA911 .P65 1997
Introduction to theoretical and computational fluid dynamics / C. Pozrikidis.

QA484 .A7513 2001
Pi-unleashed / Jorg Arndt, Christoph Haenel ; translated from the German by 
Catriona and David Lischka.

QA445 .C36 2001
A course in modern geometries / Judith N. Cederberg.

TJ1075 .S348 2001
Biological micro- and nanotribology : nature's solutions/ Matthias Scherge, 
Stanislav N. Gorb.
----------------------------------------------------------------

Suppose that the characters from the beginning of the first line to the 
first blank space in the first line are a classification scheme for items 
that the NIST library wishes to register in some ebXML conforming Registry. 
The NIST library has a URL that points to a home page somewhere on the web 
that explains the meaning of the first 2 characters of the classification 
scheme and, separately, the meaning of the subsequent numeric digits before 
the first period, and separately, the meaning of any digits after the first 
period and before any blank spaces. The URL is

    http://www.goodexplanations.com     -- I just made this up!

Suppose everyone agrees that the "goodexplantions" site does a fine job of 
explaining the library classification scheme, but that the explicit nodes 
of the scheme do NOT exist in any ebXML conforming Registry. The NIST 
Library would still like to register its books in a conforming ebXML 
Registry and classify those books by this well-understood classification 
scheme.

How should the NIST Library proceed?

Let's agree that "goodexplantions" has done a wonderful job of defining 
this 3-level classification scheme and that everyone who visits the site 
comes away knowing that a string like "TA357.5" should be parsed as "TA" 
for level 1, "357" for level 2, and "5" for level 3. Everyone agrees that 
"TA357.5" is the proper string to use for representing those three levels. 
In effect the 3 levels will always be concatenated into a simple string.

QUESTION-1: Will our specification support the NIST Library's attempted 
registration of the library classification scheme with the ebXML conforming 
Registry R as follows:

    NIST submits a new ExtrinsicObject instance to R with
      name = "urn:nist-gov:cs:libv001"
      description = "A complete explanation of the NIST Library 
Classification Scheme"
      objectType = "ClassificationScheme"
      userVersion = "2001"
      stability = "DynamicCompatible"
      expirationDate = "2002-09-06"
      contentURI = "http://www.goodexplanations.com"


QUESTION-2: Given that the registration of the classification scheme is 
successful, will our specification support the NIST Library's attempted 
registration and Classification of the 6 books as follows:

    NIST submits a new ExtrinsicObject instance to R with
       name = "Boundary integral and singularity methods for 
linearized  viscous flow"
       description = "A classic text by a famous author"
       objectType = "OnLineBook"
       contentURI = "ftp://library.nist.gov/book/TA357.5/V56/P69/1991"

    In the same XML document as the above NIST submits a Classification 
instance
       id = null
       name = "urn:nist-gov:cs:libv001"
       classifiedObject = IDREF to the above item
       classificationNode = IDREF to the below item

    In the same XML document as the above NIST submits a ClassificationNode 
instance
       id = null
       name = null
       parent = null
       code = "TA357.5"

    The other 5 books below are registered in the same manner


QUESTION-3: In the above QUESTION-2, would it make sense to define some 
nested XML submissions so clients wouldn't have to construct superfluous 
IDREF's?


QUESTION-4: Assuming that the Registry R accepts the registration of the 6 
books, will the following query return the RegistryEntry identifiers for 
the 4 "Mathematics/ComputerScience" books, i.e. the "QA" books, listed below?

   <RegistryEntryQuery>
      <HasClassificationBranch>
          <ClassificationFilter>
              name EQUAL "urn:nist-gov:cs:libv001"     -- put into Clause 
syntax
          </ClassificationFilter>
          <ClassificationNodeFilter>
              path STARTSWITH "QA"                     -- put into Clause 
syntax
          </ClassificationNodeFilter>
      </HasClassificationBranch>
   </RegistryEentryQuery>

NOTE: There is some subtle interplay between the "path" and "code" 
attributes in ClassificationNode and the "name" attribute in Classification 
and RegistryEntry. Our specification is currently silent on this interplay. 
We need more semantic rules!!

Regards,
Len


**************************************************************
Len Gallagher                             LGallagher@nist.gov
NIST                                      Work: 301-975-3251
Bldg 820  Room 562                        Home: 301-424-1928
Gaithersburg, MD 20899-8970 USA           Fax: 301-948-6213
**************************************************************