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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