Len, I consulted with two colleagues on these issues, and I don't think I am
entirely clear yet on all aspects of the proposals. Here are some general
comments (with input from two very talented colleagues!)
I am trying to make sure I understand exactly what is proposed, so have
tried to write my questions and understanding in very simple vocabulary.
The following makes sense (our understanding derived from the Sept 6th
e-mail, subject - Implicit Library Classification Schemes, see below)
1. A site exists that contains the entire Library of Congress classification
schedule.
2. This entire site will be URLreferenced in an electronic repository for
use in assigning classification numbers to electronic resources.
(urn:nist-gov:cs:libv001)
3. The query outlined in Len's Question 4 - searching on the 'QA' - should
return Mathematics and Computer science books.
In reference to the formulations in Len's question 2 of the subject e-mail
(below), does this mean that a code instance is submitted with a null id -
in other words, is there an attempt to develop an outline of the LC
classification numbers that exist with no reference to the works that are so
classified? In other words, is it proposed to recreate the entire LC
classification with nulls? Perhaps I am misunderstanding here, but it seems
if there is an existing classification in an electronic format for
referencing, what is the purpose in recreating it in its entirety in each
registry that wants to use that particular classification schedule when
there may not be objects associated with some of the pieces of the
classification scheme? It does make sense to be able to query on the
classification codes associated with the items in a particular registry (as
illustrated above), but in this case the only classifications in the
registry would be those that had associations with actual items registered.
Am I mis-understanding something here?
Len's e-mail:
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
> ----------
> From: Len Gallagher[SMTP:]
> Sent: Thursday, September 13, 2001 2:37 PM
> To: OASIS ebXML Registry Ext Scheme
> Subject: External Classification Scheme -- Meeting Report
>
>
> External Classification Team,
>
> Our September 13 teleconference was attended by three people:
>
> Len Gallagher
> Nikola Stojanovic
> Farrukh Najmi
>
> We discussed the differing proposals by Len and Farrukh to treat
> ExternalClassification as a subclass of Classification, or implicitly, to
> treat Classification as a superclass of both InternalClassification and
> ExternalClassification. The team is very close to agreement on RIM changes
>
> needed to accommodate a common interpretation of both types of
> classifications.
>
> There are still some differences on whether Classification instances must
> be supported in Registry Services for all RegistryObject subclasses, or
> just some subset of them, in particular RegistryEntry and possibly
> Organization.
>
> It would be helpful if other team members commented on the proposals.
>
> -- Len
>
>
> **************************************************************
> Len Gallagher
> NIST Work: 301-975-3251
> Bldg 820 Room 562 Home: 301-424-1928
> Gaithersburg, MD 20899-8970 USA Fax: 301-948-6213
> **************************************************************
>
>
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