The problem that I have with Dr. Moen's study is that it leads us to believe that catalogers actively make decisions about which tags to use (or not to use) in MARC records.  Yes, I will concede that there is an occasional bit of "cataloger's judgment" reflected in MARC records.  However, the existence or non-existence of a particular field in a record is usually driven by the publication itself, not by the cataloger.  If a book has a series, then there will be 490 and 830 fields in the record.  If the program notes for a sound recording state the performers, then there will be a 511 field.  If we look at the percentages, 511 fields are little used, not because catalogers choose not to input them, but because sound and video recordings represent only a small percent of total publications.  And then, even within those formats, not every recording includes a statement about the performers.

--
Matthew Wise, Music Cataloger
Knowledge Access and Resource Management Services
Division of Libraries, New York University
20 Cooper Square, Room 313, New York, NY 10003-7112
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On Sat, Nov 5, 2011 at 4:24 PM, Karen Coyle <[log in to unmask]> wrote:
Quoting Roy Tennant <[log in to unmask]>:

I believe you are missing the point. The evidence is clear -- the vast
majority of the some 3,000 data elements in MARC go unused except for a
small percentage of records in terms of the whole. What isn't there cannot
be indexed or presented in a catalog, no matter how hard you try. In other
words, which fields were coded is the only relevant information. It is the
ONLY relevant information when you are discussing how to move forward.

I disagree. (As does the OCLC report, BTW) To some extent the stats on MARC records reflect the many special interests that MARC tries to address. I have spent more time on the Moen statistics [1] than the OCLC ones, although since they were done on the same body of data I don't see how they could be very different.

In the case of what Moen turned up, the most highly used fields were ones that systems require (001, 005, 008, 245, 260, 300) -- it's a bit hard to attribute that to cataloger choice. But for the remainder of the fields there is no way to know if the field is present in all of the records that it *should* be, or not.

At least some of the low use fields are ones that serve a small-ish specialized community. Only 1.3% of the OCLC records have a Cartographic Mathematical Data (255), but according to the OCLC report that represents a large portion of the Maps records (p. 23 of OCLC report). It's harder to make this kind of analysis for fields that can be used across resource types. For example, 35-47% of the records (OCLC v. LC-only, respectively, from Moen's stats) have a Geographic Area code (043). Undoubtedly some records should not have that field, so is this field a reliable indicator that the resource has geographic relevance? We have no way of knowing. In addition, as MARC fields are constantly being added, some fields suffer from not having been available in the past. (Moen does a comparison of fields used over time [2], and the OCLC report also looks at this; see below.)

Neither the Moen stats nor the OCLC report really tell us what we need to know. It's not their fault, however, because we have no way to know what the cataloger intended to represent, nor if the MARC record is complete in relation to the resource. My experience with some specialized libraries (mainly music and maps) was that these communities are diligent in their coding of very complex data. These, however, represent only small numbers in a general catalog.

The OCLC report reaches this conclusion:

"That leaves 86 tags that are little used, or not used at all, as listed in the ?MARC 21 fields little or not used? table (Table 2.14, p. 32). Of these infrequently occurring fields, 16 are fields that were introduced between 2001 and 2008. Three of these fields (highlighted in orange) have no occurrences in WorldCat since OCLC has no plans to implement them."

This means that there are really 67 fields that seem to be underused. That is out of 185 tags (not 3000, which would be more like the number of subfields). That's about 1/3. Having sat in on many MARBI meetings, however, I am sure that there are communities that would be very upset if some of these fields were removed (e.g. musical incipits, GPO item number). Admittedly, some fields were introduced that then turned out not to be useful. If those can be identified, so much the better.

Basically, there is no way to know a priori what fields *should* be in a MARC record other than the few that are required. Deciding which fields can be left behind is going to take more than a statistical analysis. I agree that we should not carry forward all MARC data just "because it is there." The analysis, though, is going to be fairly difficult. Even more difficult will be the analysis of the fixed fields. I could go on about those at length, but that analysis will be complicated by the fact that the fixed fields are frequently a duplicate of data already in the record, and we never should have expected catalogers to do the same input twice for the same information -- we should have had a way to accomplish indexing and display with a single input.

kc
[1] http://www.mcdu.unt.edu/?p=41
[2] http://www.mcdu.unt.edu/?p=47


The one thing you said that I agree with wholeheartedly, is that we should
know what data is useful to users. Yes. That.
Roy


On 11/4/11 11/4/11 € 10:41 PM, "J. McRee Elrod" <[log in to unmask]> wrote:

Roy Tennant <[log in to unmask]> wrote:


"Implications of MARC Tag Usage on Library Metadata Practices"
http://www.oclc.org/research/publications/library/2010/2010-06.pdf

This study told us what fields were in records, not whether those
fields were utilized in OPACs.  MARC has a wealth if information never
put to practical use.   Which fields were coded is fairly useless
information.

A study of what fields OPACs actually use might be helpful, but that
still does not tell us what fields might be helpful to patrons if they
were utilized,'


  __       __   J. McRee (Mac) Elrod ([log in to unmask])
 {__  |   /     Special Libraries Cataloguing   HTTP://www.slc.bc.ca/
 ___} |__ \__________________________________________________________





--
Karen Coyle
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