RE: Bib-2 and the DC-Lib: Duration

Hello Barbara,

To reply to Mike - the "core" fifteen elements have not changed since the
document cited.  The DC family of elements has moved on in that it now also
encompasses a set of qualifiers.  These fall into two groups - element
refinements (such as Medium and Extent that refine Format) and encoding
schemes such as IMT.  I am not familiar with Bib-2 but gather that you are
using only the 15 (collapsed to 13) elements of DC in that context.  Is this
so?

DC-Lib suggests using the *unqualified* Format element to specify the
electronic format of the resource - thus the best practice recommendation to
use a controlled vocabulary (IMT in this case) is appropriate.  In the DCMES
reference document IMT is given only as an example and is not intended to
cover all possibilities.

As you say, the concept of duration (and size) should be expressed by
qualifying Format with Extent.   A controlled vocabulary would not be
appropriate here but a standard syntax could be adopted (?hh:mm:ss) and
shown as an encoding scheme if it is such. No recommendation about encoding
schemes has been made about this yet and further work is needed.

For the sake of completeness: DC-Lib defines Format.Medium for use where
there is a physical carrier for a resource.  If it is both electronic and on
a physical carrier (pdf file on a cd) then both would be used.

Regards,
Robina  



-----Original Message-----
From: Shuh Barbara [mailto:barbara.shuh@nlc-bnc.ca]
Sent: 23 April 2002 20:36
To: 'Clayphan, Robina'; Gladwell, Kevin; www-zig@w3.org
Cc: Oldroyd, Bill; Alexander, Michael; Masters, Richard
Subject: RE: Bib-2 and the DC-Lib: Duration


Robina,

Interesting to see where DC has pigeon-holed information on "Duration"...

Lennie and I defined a separate access point in Bib-2 for "Duration" because
we could find no place in the Cross Domain set to express this value.   It
didn't seem to fit within the definition for Format given in the
Cross-Domain (XD) set.

I note that the XD Format has the same definition as the DC element:  "The
physical or digital manifestation of the resource."    But somehow, DC has
added other concepts into this element and ended up with the element
representing two different concepts.  

(FRBR seems to agree that they're different things.  Note that in FRBR (the
Functional Requirements for Bibliographic Records)
(http://www.ifla.org/VII/s13/frbr/frbr.pdf), a recent logical analysis of
the data typically reflected in bibliographic records,  duration is
described at a different level than attributes describing the format.
(Duration is an attribute of the "expression"  (4.3.8) while the physical
medium (aka Format) is an attribute of the "manifestation" (4.4.11) .)  

In Bib-2, "Format" is used for such things as the IANA media type (same as
the DC-Lib "Format/IMT") and the type of record in MARC (same as the DC-Lib
"Format/medium")  

But I find it very confusing to see that DC-Lib has mixed the concept of
"duration" in with these things.  The the stated "recommended best practice"
of DC-Lib  "Format" is to select a value from a controlled vocabulary (for
example, the list of Internet Media Types [MIME] defining computer media
formats.)   What kind of "value from a controlled vocabulary" can be used to
express time duration?  If it can't be expressed as a value from a
controlled vocabulary, then is it really the same thing?  It doesn't make
sense to me!   

Bib-2 identifies the default format of that information (according to the
specs. in ISO 8601: 1998 (E), Clause 5.5.3.2) 

When developing Bib-2, we found that if other attributes such as a list of
Content Authorities or Semantic Qualifiers applied to only a partial
selection of the list, then maybe what we had were different access points,
and so went back to the drawing board.  It looks as if DC developers weren't
concerned about that problem.  

But, in the end, as I see it now, there should be no problem, to continue to
carry Duration as a separate element in Bib-2.   It can be mapped to the
"Format/extent/duration" in a DC-Lib Profile record.  (But at the current
time, with no guidelines in DC as to how to express a duration, the chance
of meaningful retrieval would be low...)

Barb  
______________________
Barbara Shuh
Library Network Specialist
National Library of Canada
Phone:  (613) 995-1701  Fax:  (613) 943-1939
E-mail:  barbara.shuh@nlc-bnc.ca


-----Original Message-----
From: Clayphan, Robina [mailto:Robina.Clayphan@bl.uk]
Sent: Tuesday, April 23, 2002 7:18 AM
To: Shuh Barbara; Gladwell, Kevin; www-zig@w3.org
Cc: Oldroyd, Bill; Alexander, Michael; Masters, Richard; Clayphan,
Robina
Subject: RE: Bib-2 and the DC-Lib


Hello Barbara,

Temporal/Coverage.  The DC-Lib does not propose that this is used for the
duration of a resource.  Duration should be recorded in Format/Extent.  

DC-Lib should maybe put a note in for the sake of clarity.  At the moment,
for Coverage/Temporal it echoes the definitions in the DC Element Set and DC
Qualifier documents and the Usage Guide.  A Best Practice note allows use of
the same date formats as proposed in DC-Lib for the Date elements but some
of these are yet to be defined.  I suspect the confusion arises from the use
of the word "extent" in the definition of Coverage where it is referring to
what the intellectual content covers rather than how long a resource will
take to execute.

(Edited from the Usage Guide) "Element Description: The extent or scope of
the content of the resource. Coverage will typically include ... temporal
period (a period label, date, or date range) ... . Recommended best practice
is to select a value from a controlled vocabulary .... and that, where
appropriate, named places or time periods be used in preference to numeric
identifiers such as sets of co-ordinates or date ranges."
http://dublincore.org/documents/2000/07/16/usageguide/sectb.shtml#coverage

Regards,
Robina



-----Original Message-----
From: Shuh Barbara [mailto:barbara.shuh@nlc-bnc.ca]
Sent: 22 April 2002 17:38
To: 'Gladwell, Kevin'; www-zig@w3.org
Cc: Oldroyd, Bill; Alexander, Michael; Masters, Richard; Clayphan,
Robina
Subject: RE: Bib-2 and the DC-Lib


Thanks, Kevin, for your 5 questions.  I've responded to each point you made
below.  As has been suggested by Rob and I in the list discussion earlier
today,  I think that the response for most issues is that, where the data,
as defined in the DC-Lib Profile, does not match the Bib-2 attributes, and
is not covered in other Attribute Sets (such as the Utility Set and the MARC
Set), that a separate set be developed for DC-Lib.  

If names of elements have to be changed to match the Z39.50 queries up with
DC, then it has to be done in the Cross Domain Set first.    

And, Kevin, I would welcome some elucidation on the etc., etc., etc., if you
have time - over time.


i) DC-Lib uses DC CREATOR, CONTRIBUTOR and PUBLISHER however they also
defined a qualifier called DCMI Agent Detail which can be family name, given
names, name, affiliation location, description, date time and identifier.
In Bib-2 there are 4 different structural qualifiers for NAME.  How could
Bib-2 be used to search for a family name in a document described by DC-Lib?

BAS:  I would expect that the search would have to be mapped to:
(1) Access Point [Cross-Domain Set] = (3) Name
(2) Semantic Qualifier [Bib-2] = (3) Personal

If one really needs to get more specific, one would include attribute from
the MARC Attribute Set limiting the search to those personal name attributes
where Tags 100 and 700 1st indicator = 3  Family name.

ii) DC-Lib for RESOURCE TYPE uses DCMI Type Vocabulary
(http://dublincore.org/documents/2000/07/11/dcmi-type-vocabulary/) as
qualifiers to Resource Type, these are not included in Bib-2.

BAS:  I see that DC-Lib specific vocabularies such as this would be part of
an auxiliary DC-Lib attribute set.

iii) DC-Lib and Bib-2 for SUBJECT both have the content authority (encoding
schema in DC-Lib) of LCSH, LCC, MeSH and UDC.  DC-Lib also has DDC and bib-2
has 18 additional content authorities.

BAS:  I don't see a problem here.   Bib-2 has provided an enumeration of the
codes that are explicitly used in MARC 21 (LCSH, LCC, MeSH, NAL, CSH and
RVM), plus a list of different subject and classification systems that were
covered in Bib-1, but not in the MARC lists.  

iv) DC-Lib uses coverage/temporal for duration and coverage/spatial for
geographic referent.  Coverage/spatial includes using the Thesaurus of
Geographic Names.

BAS:  I believe that we had discussion on these attributes at the Boston Spa
meeting, and at that time, Paul Miller indicated that the DC data element,
Coverage, didn't apply to such things.  But it looks like the story has
changed since last October, because the DC documentation appears to have
extended the meaning of that element to cover these elements.   

And the definition of the "Coverage" attribute in the Z39.50 Cross-Domain
set gives no hint that such attributes as duration and geographic referrent
should be covered there.  Since Bib-2 is closely tied to the Cross-Domain
Attribute Set, it is in the Cross-Domain Set that the change would first be
made.  

BUT, 
From the definition given for Coverage/temporal, I'm not sure what it is.
(Hint to Robina that the text of this DC-Lib definition is not very clear:-)
Presumably, you think that it is meant to convey "Duration" - but I can't
tell from the definition given in DC-Lib.

RE:  "Coverage/Spatial" 
Although the DC Encoding schemes include things like the MARC Geographic
Area Codes and MARC Country Codes, the recommended best practice is to use a
value from a controlled vocabulary, (such as the Thesaurus of Geographic
Names) and not to use numeric identifiers such as sets of coordinates or
date ranges.

v) The DC-Lib DATE has some qualifiers that are not in Bib-2 e.g.
date/modified how would this be searched for using Bib-2?

BAS:  This query uses elements defined in the Utility Set, so not required
in Bib-2
I.e.,
(1) Access Point [Utility Set] = (1) Record Date/time
(12) Functional Qualifier [Utility Set] = (3) Modification


Barb
______________________
Barbara Shuh
Library Network Specialist
National Library of Canada
Phone:  (613) 995-1701  Fax:  (613) 943-1939
E-mail:  barbara.shuh@nlc-bnc.ca


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**********************************************************************
Coming soon to the British Library Galleries :

Trading Places : the East India Company and Asia (from 24 May)
Magic Pencil : Children's Book Illustration Today (from 1 November)
**********************************************************************
The information contained in this e-mail is confidential and may be 
legally privileged. It is intended for the addressee(s) only. If you 
are not the intended recipient, please delete this e-mail and notify 
the postmaster@bl.uk : The contents of the e-mail must not be 
disclosed or copied without the sender's consent. 

The statements and opinions expressed in this message are those of 
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Library. The British Library does not take any responsibility for 
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Received on Wednesday, 24 April 2002 07:30:51 UTC