On Thu, Jun 10, 2010 at 5:02 PM, Samuele Kaplun <[email protected]> wrote:
Currently when you use xmlmarc2textmarc utility, and you export to
Aleph, a dummy leader is generated, which proved to be enough for Aleph.
Ahh, I wasn't aware of that existing utility. I showed the marc output
from bibformat to some librarian coder friends and they said, "huh,
looks like aleph sequential" :)
So Aleph doesn't care about the leader values?
I am currently not an expert on the leader subject, but to me it seems
that the leader makes sense mostly in the MARC21 binary format, and when
dealing with plain library records. And it exists in MARCXML just as a
conversion consequence. Is this correct? Proof is that Invenio can do
powerful and extremely flexible things without any need for the leader.
Not an expert either. I think for Invenio it really just boils down to
interoperability. I mean, saying, Software X can do incredible,
amazing things with internal, non-standard format Y, isn't really a
remarkable statement.
In particular if Invenio has to support the leader in MARCXML how can we
map its workflows with the rigid schema of the leader:
I think sensible defaults for some values combined with a minimum of
conditional logic should suffice. The first part of that may be the
trickier as I'm still trying to figure out defaults myself.
Also what is the meaning of certain bytes of the leader in MARCXML:
(from <http://www.loc.gov/marc/bibliographic/bdleader.html>):
[...]
Character Positions
00-04 - Record length
[...]
12-16 - Base address of data
[...]
leader/05 = 'n' - the term "new" in this context is confusing but
I've been told "don't overthink it"
leader/06 = 'a' - "...electronic resources that are basically textual in nature"
leader/07 is where i'm less confident but I *think* the logic is
simply 'b' for articles, 'a' for things that are part of a collection
or proceedings, and 'm' for everything else. For ADS we are currently
storing our internal item-type description in the 690a (which may be
incorrect) and this is how i'm determining the leader/07
leader/08 = '#' - not sure about this one
leader/09 = 'a' - assuming unicode
I've been looking at http://www.itsmarc.com/crs/bib1465.htm for some
guidance and when I have a dumb question about something I'll ask in
the #code4lib irc channel.
Apparently the 008 control field
(http://www.loc.gov/marc/bibliographic/bd008.html) is also important
to many applications, but I haven't really explored it or determined
the level of importance.
In the end, probably the best thing is still to put a fake leader like
xmlmarc2textmarc currently does, with the most neutral values.
Yeah, I guess I agree, although I'm not sure what a "neutral" value
would be for something like the leader/07. also it's important to get
the leader/09 correct as tools like pymarc need to know how to decode.
It is true that, on the other hand, when Invenio records have been
imported from original MARC21 or from MARCXML with a leader, Invenio
should not throw away such information.
Agreed.
--jay
******************************************************
Jay Luker Astrophysics Data System (ADS)
[email protected] Center for Astrophysics
617-495-4588 60 Garden Street MS 67
617-495-7356 fax Cambridge, MA 02138
******************************************************
