I found it worthwhile to go back to this 2002 article on the problems identifying expressions for the work "Humphry Clinker", as it highlights some of the early difficulties in applying FRBR expressions to existing bibliographic data:
http://www.oclc.org/research/publications/library/2002/oneill_frbr22.pdf There are a number of issues that arise, and that reflect how expressions have been and can be implemented. Understanding how to approach aggregate expressions is complicated by the legacy effects of our current systems. 1. Current expression-level organization is often at what I would call an "expression group" level, rather than distinct expressions. For example, the authority controlled heading for Tolstoy's War and Peace: Tolstoy, Leo, graf, 1828-1910. Voina i mir. English doesn't distinguish the different translations in English. Some of the expression level organization offered in systems like VTLS is at this grouping level, with distinguishing elements generally limited to Content Type and Language. 2. Some methods to identify unique expressions require the Contributor relationship. For example, one could say translator, editor, and illustrator are core elements if these are the only ones that can distinguish expressions. These go beyond the expression attributes listed in RDA Section 2 (Recording Attributes of Works and Expressions). This ties in with my earlier comment that the Contributor relationship can be essential, in that it can make or break the boundaries for a distinct expression. 3. The expression attributes can be found scattered currently in either MARC bibliographic and MARC authority records, which adds to the complexity in thinking about expressions as distinct entities, and in modelling aggregate expressions. RDA Chapter 6 covers the attributes usually found in authority records and in authorized access points (essentially the instructions for uniform titles and added entry headings). RDA Chapter 7 covers the expression attributes usually found in bibliographic records, such as Summarization of the Content, Illustrative Content, and Supplementary Content. The RDA Element Set View on the other hand, organizes all the attributes for an expression together, with an organization for "Core", "Enhanced", and "Specialized" attributes, and these are followed immediately by the Relationship elements -- the primary relationships, the Contributor relationship, and the Related Expression relationships. There are some odd results: It might be good to say an expression has a bibliography (in the sense of a fixed field value), but the examples in RDA root this expression to specific manifestations (RDA 7.16.1.3): "Bibliography: pages 859–910" Similarly, additional information about a Contributor relationship can be added to notes, which RDA 18.6 directs to manifestation attributes (this is where one finds the comparable sense to "justify the added entry" in the description). The other odd result: Related Expression relationships can be found in authority records (See Also references), or in bibliographic records when Identifiers, Structured Descriptions, and Unstructured Descriptions are used. ... So for the way VTLS handles this, there is a good use of the vertical relationships, the many-to-many relationships of Expressions embodied in Manifestations with the example of: Short story - "The fires of hell" found in 3 manifestations. Reoriented to... One of the manifestations - "Port o' missing men" manifestation showing the embodied expressions (rather work/expression details) of each short story, allowing for navigation to be enhanced. What appears to be missing is the ability to add the horizontal relationships-- the Whole-Part relationships from an individual expression to an aggregate expression, or to other related expressions. The split in MARC authority and bibliographic data seems to hamper this flexibility, which means that expression modelling is limited to the attributes that exist in bibliographic records. For many application purposes, this might be sufficient, but it does mean a lot of baggage has to be carried to try to model aggregates out. Thomas Brenndorfer Guelph Public Library > -----Original Message----- > From: Resource Description and Access / Resource Description and Access > [mailto:RDA-L@LISTSERV.LAC-BAC.GC.CA] On Behalf Of Heidrun Wiesenmüller > Sent: January 16, 2012 11:41 AM > To: RDA-L@LISTSERV.LAC-BAC.GC.CA > Subject: Re: [RDA-L] Some comments on the Final Report of the FRBR Working > .. > > If we discard the idea of aggregating works and aggregating expressions > in the sense of the Working Group, we are back to aggregate works, and > there is certainly more than one way of modeling them. > > Personally, I can think of four possibilities, which I've tried to > visualize in yet another paper: > http://www.mendeley.com/profiles/heidrun-wiesenmuller/ > under "Working papers", called "Additional diagrams #3" > or directly under: http://tinyurl.com/7wskyjp > > I didn't have the time to comment on them thoroughly, but I hope the > main differences are clear from the diagrams. If you can think of more > ways of modeling aggregates, please let me know. > > The next step should be to take a number of interesting cases (e.g. an > augmented edition; a monographic series; two collections containing > different expressions of the same works; a journal article as part of an > aggregate work and as an off-print; a collection of essays as part of an > aggregate, i.e. the question of recursiveness) and see what the models > would look like in these cases. Then it should be possible to compare > them as to their strengths and weaknesses. Hopefully, one model would > stand out in the end as the one which works best. Then this could be a > basis for questions of technical implementation. >
