Karen Coyle wrote:
>
> I think this becomes a question of how we express WEMI -- you can  
> always link from/to any WEMI using "contains" or "contained in" -- so  
> you can always link to all of the Works in an aggregate. What I would  
> like to achieve is for different decisions (like one community calling  
> the aggregate a Work/Expression and another focusing on the individual  
> works and linking those to a Manifestation) to not create incompatible  
> data.
>   
Keep in mind that EVERY item-in-hand MUST be a Manifestation.   At least 
this is my interpretation of FRBR.

If you have a bound volume that's an "aggregate", it HAS to be a 
manifestation. There is no way to model it purely as an expression.  
Works and Expressions are abstract things that I prefer to think of as 
sets of manifestations. Really, manifestation is officially abstract 
too, it's only Item that is a concrete physical thing. But in library 
cataloging we're used to thinking of Items as interchangeable elements 
of a Manifestation, and Manifestation is CLOSER to the ground than 
Work/Expression. You simply can't have a physical object which is "just" 
a Work or Expression and not a Manifestation (and an Item too), that is 
not the model. 

Every item in hand is an Item, which belongs to a Manifestation set (and 
in traditional library cataloging is considered interchangeable with 
other Items of that Manifestation for our patrons, and thus we don't 
generally record metadata below the manifestation level), which also 
belongs to an Expression set and a Work set. (and in traditional library 
cataloging, members of expression or work sets are NOT considered 
interchangeable for our patrons, for obvious reasons; they may be in 
different languages, different mediums, or just be different editions.).

So there's no way to "call an aggregate a Work/Expression" _instead of_ 
a manifestation, if that aggregate is an actual physical item in your 
hand.  If people on the RDA-L list came to a "consensus" that is 
otherwise... I suspect you misunderstood them, but otherwise their 
consensus does not match any interpretation of FRBR I have previously 
encountered, or any that makes sense to me.

You've got a manifestation whether you like it or not.   The question is 
how much "authority work" are you going to do on identifying the 
Expression and Work it belongs to.  If you don't do much because it 
doesn't make sense for you to do so, maybe it starts out modelled as a 
manifestation just belonging to a "dummy" Expression/Work that contains 
only that Manifestation. Some other cataloger somewhere else does the 
"authority" work to flesh out an Expression and/or Work that maybe 
contains multiple manifestations or maybe doesn't. Is your data 
incompatible?  Not really, it can be merged simply by recognizing that 
your "dummy" Expression/Work can be merged into their more fleshed out one.

There's also a question of how much "authority work" you want to do on 
the _contents_ of the aggregate. Maybe you don't want to spend any time 
on that "analytical" task at all, and your record does not reveal that 
the item in your hand IS an aggregate, it does not actually expose 
relationships to the other Works/Expressions contained within. It might 
have a transcribed table of contents as an attribute only, not as a 
relationship to other entities.  Later some other cataloger fleshes that 
out. Here too, that other catalogers extra work can be (conceptually at 
least) easily "merged in" to your record, there is no incompatibility.

[If two different catalogers/communities decide that two different Works 
contain _different_ manifestations, and violently disagree, then THAT's 
an incompatibility that's harder to resolve and is a legitimate 
concern.  But that's not what we have in this example, which is quite 
straightforward.]

While to some extent I sympathize with your inchoate thoughts about 
modelling WEMI being a mistake, and we've talked about that before -- 
ultimately I still disagree. It is appropriate to use an 
entity-relation-attribute model to come up with the kind of explicit and 
formal model of our data that we both agree we need.  It's a 
conventional, mature, and well-tested modelling approach (I wouldn't 
want to pin all our eggs to RDF experimentation that at least arguably 
does not rely on an entity model).  You can't have an entity model 
without entities.   The FRBR WMI (and more debatably E) entities are the 
ones that clearly come out of a formalization of our 100 year tradition 
of cataloging, meaning there's probably something to them AND that using 
them makes retroactively applying the model to our 100 years worth of 
legacy data is more feasible (and BOTH of those facts are totally 
legitimate grounds for decision making.  And the decision has already 
been made too, although in the case of FRAD I'd still be reluctant to 
accept it as a "done deal", but in the case of FRBR, it is much better 
done, a much more useful and accurate abstraction of our cataloging 
tradition). 

Should we take this back to RDA-L (where I'll probably begin paying only 
intermittent attention to it again; for my purposes/interests, there is 
a lot of 'noise' on RDA-L).

Jonathan



> I've had this ill-formed notion for a while that we shouldn't actually  
> be creating WEMI as "things" -- that to do so locks us into a record  
> model and we get right back into some of the problems that we have  
> today in terms of exchanging records with anyone who doesn't do things  
> exactly our way. WEMI to me should be relationships, not structures.  
> If one community wants to gather them together for a particular  
> display, that shouldn't require that their data only express that  
> structure. I'm not sure FRBR supports this.
>
> sound vague? it is -- I wish I could provide something more concrete,  
> but that's what I'm struggling with.
>
> kc
>
>   
>> This seems a pretty convincing argument to me?
>>
>> But it's not unique to musical recordings. If I have the Collected
>> Works of Mark Twain, which includes the complete Tom Sawyer... how can
>> Tom Sawyer not be a work? And how can the Tom Sawyer that's in the
>> Collected Works NOT be the same work as the Tom Sawyer that's published
>> seperately?
>>
>> If that was "the conclusion on the RDA-L list", it makes no sense to me.
>>
>> Jonathan
>>     
>
>