In geology, stratification can refer to the different layers of rocks that have formed over a given number of years. When it concerns AACR2 and RDA bib records, the word 'stratification' has started to gradually build up significant meaning for us here at Backstage. During my time spent as a member for the recent PCC Post-Implementation Task Group on Hybrid Bibliographic Records <http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&cad=rja& ved=0CEAQFjAC&url=http%3A%2F%2Fwww.loc.gov%2Faba%2Fpcc%2Frda%2FRDA%2520T ask%2520groups%2520and%2520charges%2FPCC-Hybrid-Bib-Rec-Guidelines-TG-Re port.docx&ei=Zce_UI67JKq5igKw04AI&usg=AFQ> (June - Oct 2012), we discussed whether it was a good idea to suggest the creation of a new ID (040 subfield) for hybridized AACR2 bib records. The consensus was against this idea. So we are left with bibs that are either RDA or non-RDA. This is an oversimplification, but I'm hoping more explanation below might help illustrate some of our concerns. Our task group also could not definitively establish what the 'tipping-point' would be for determining when a bib record has crossed the threshold from AACR2 bib to clearly an RDA bib. We seemed to settle on the actual designation (i.e., adding 040 $e rda) only when the cataloger has the item in-hand and is re-describing the record to RDA format. Lacking the item in-hand means that the AACR2 bib could have any number of RDA-type elements (33X, etc) added to it, but the sum of these added fields still is not enough to confidently re-describe the bib as RDA. I think one of the main reasons was that, technically, most or all of these RDA-element fields are also fine being in AACR2 bibs. This brings us back to the stratification issue. Even though there may be many layers of fields added which would surely tip it over into being an RDA bib record, we cannot with confidence call it RDA unless there is an 040 $e rda field present. As there is no definitive ID present in a bib that has had RDA-type fields added to it-assuming absence of 040 $e rda-then our conclusion is that the record must be in AACR2 format. This doesn't seem right, but it is the case today. Consequences of this way of thinking means that, for some libraries that have us remove relationship designators (X00 $e) in AACR2 bibs but retain them in RDA bibs might run the risk of having us remove those from AACR2 bibs that have been hybridized with RDA elements. This is probably not desirable? And there might be other types of updates or validation (e.g., 250, 260, 300 field expanding abbreviations) performed on AACR2 or RDA records that would be preferable to also apply to those special hybrid AACR2 records. We welcome your thoughts on these types of matters as we inch ever closer to March 31, 2013. Nate Cothran Vice President, Automation Services 533 East 1860 South Provo, Utah 84606 Phone: +1.800.288.1265, ext. 697 Direct: +1.801.342.5697 nate@bslw.com <mailto:nate@bslw.com?subject=Automation%20Services%20-%20Inquiry> * www.bslw.com
