Actually John, I believe Jay Weitz did mention this solution, and possibly one or two others, but simply did not provide an example showing it, in the manner that you did. LC G&M catalogers have been using this technique for many years. For me the issue becomes; if there isn't a date of any kind or some other obvious difference to indicate a change from an existing record and one I may be creating that might actually become a duplicate, how much time am I going to put into looking through the cartographic content to try and spot meaningful differences to indicate that something is a "new" edition?

As I've followed this conversation from its beginning with Angie's post, I also am wondering if catalogers are proactively checking to see if something they have created has been merged (correctly or incorrectly) and if so, how? I know I certainly do not have time to somehow monitor every record I create (and admit that I don't create all that many per year that perhaps others do) and so how are you finding out that a record has been incorrectly merged?

I report duplicates on a pretty consistent basis and believe I make good decisions about whether two or more records are actually describing the same map, but at times some records are woefully short on descriptive elements to make me feel 100% sure about whether something is a duplicate or not and in those cases I err on not considering them a duplicate. If the deciding factor on whether something is or is not a match lies in data in 500 notes then I can see why the Duplicate Detection System could fail to account for something truly being a different edition at times. Its good to hear from Jay that the QC group and others at OCLC continue to tweak the DDS to make it better based on input from catalogers, and I am confident that the small group of folks he oversees do the right thing the vast majority of time to the benefit of us all.

Paige

From: "John Stevenson" <[log in to unmask]>
To: "[log in to unmask]" <[log in to unmask]>
Sent: Friday, October 30, 2015 9:38:45 AM
Subject: Re: OCLC incorrectly merging map records

Looking through the responses, I didn't see the answer that I thought worked for special collections book and GPO map catalogers: include an edition statement, e.g.
250 |a [Planimetric edition.] 
rather than 5XX notes.

Colleagues suggest that otherwise similar records with unique values in field 250 are not merged by OCLC. I hope this helps.

On Wed, Oct 28, 2015 at 4:23 PM, Angela R Cope <[log in to unmask]> wrote:




I just discovered another record from my catalog that got incorrectly merged in OCLC. The map is an OSS map from 1943 with the same title as another map but each have different dates (months indicated in a 500 note) and different map number identifiers (also indicated in a 500 note). See oclc number 793401057 that was merged (incorrectly) with 701552600. The title and date fields (008 and 260/264) match but the 500 notes described what distinguished the two maps from one another. My library doesn't even hold the map that OCLC now says we hold.


Is there a committee from MAGIRT or WAML that is working with OCLC regarding this incorrect merging of catalog map records? Should we -  map catalogers, special collections catalogers - be keeping a record of these incorrect mergers as we discover them and then reporting them as a unified group? I'm sure for every one we discover, there are many others going undetected.    


I've reported this error via OCLC's error reporting method. We need to express some concern about the frequency of this problem to OCLC. Why are we entering data into a shared catalog if it's just getting deleted by their computers?



-Angie

Angie Cope 
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