- From: Karen Coyle <kcoyle@kcoyle.net>
- Date: Fri, 18 Mar 2011 07:43:18 -0700
- To: Antoine Isaac <aisaac@few.vu.nl>
- Cc: Martin Hepp <martin.hepp@ebusiness-unibw.org>, public-lld@w3.org, Dan Brickley <danbri@danbri.org>, goodrelations <goodrelations@ebusiness-unibw.org>
I think this becomes possible with FRBR when a class is created either for Group 1 as a whole, with WEMI being subclasses of that class (frbrCore and FRBRoo both take this approach), and/or for the three FRBR groups as a whole. This was the essence of a lengthy (and non-recoverable) thread on the FRBR discussion list, with the parties breaking down into these "thought sets": - FRBR needs a "super-class" so that relationships can be made to non-FRBR-ized bibliographic descriptions - no super-class is needed because you can link to the frbr:manifestation (which then in turn links to Expression and Work) - no super-class is needed because the Work represents the whole kc Quoting Antoine Isaac <aisaac@few.vu.nl>: > Hi Dan, > > Interesting stuff indeed :-) I wonder however whether the issue can > be sorted out in generality. Some randomly ordered two cents: > > - you need some "realization/reproduction" links between an abstract > FRBR resource and a less ghostly one, or between a design and > (re)productions of it. FRBR is not the only one facing that > requirement, models like DOLCE (the Information Objects part) or > CIDOC-CRM feature a comparable pattern. CRM is for museums, but art > that is exposed in musea now can be obtained via mechanization, or > subject to it for many purposes. One other important application > area for CRM, archeology, is of course full of "realizations" of a > more abstract design (think of coins). In fact if you want to bridge > to FRBR, you might be interested in FRBRoo, as model trying to > re-conciliate FRBR and CRM... > > - you need an operation that allows you to treat the more concrete > resources (in the above "realization" relationship) as the most > abstract resources in another realization relationship. OWL2 punning > is a solution for this, you may also think of foaf:focus as it > allows to associate an individual (concept) to anything more > concrete, which could be an OWL class. And in fact it's funny that > Martin got involved in this via the GoodRelations stuff, because a > couple of years ago he has also worked on a mechanism to bridge SKOS > concept schemes with "normal" ontologies, which seems to me quite > related. > > - once you have the patterns sketched above, you can apply them to > any number of "realization" levels. In the case of the library > domain as captured by FRBR it's 4, but in other domain as you hint > it, it could be less. It could be more as well. Very probably it > would depend on the application: here we bridge to the huge > discussion on the LLD list, where people were objecting that they > did not have the data to fully instantiate all the FRBR levels. > While in some case this lack is not intended, in other cases it > could be a fully conscious choice, based on the observation that > full compliance to the 4 levels would be impossible to reach for > data producers and/or useless for the data consumer or end user. > > - the prototype issue applies as soon as you have one level of > "realization" or instantiation, starting from the > "business-as-usual" class-instance modeling as in all simple OWL > ontologies. So I'm not sure it should be treated in strong relation > with the FRBR-like many-levels. As Martin's changing the thread > subject suggests it, I believe you could have split your impressive > post in 2 parts :-) > > Cheers, > > Antoine > > >> Hi Dan, >> >> Thanks for the interesting points, which I found only by accident. Just FYI: >> >> Both http://www.productontology.org and GoodRelations >> (http://purl.org/goodrelations) try to cater for the need of >> modeling classes, individuals, and prototypes in an OWL DL world. >> >> This happens by using >> >> a) three subclasses of gr:ProductOrService: >> - one for actual, identifiable individuals >> (gr:ActualProductOrServiceInstance) >> - one for bags of anonymous individuals >> (gr:ProductOrServicesSomeInstancesPlaceholder) >> - one for prototypes that define default attributes of individuals >> (gr:ProductOrServiceModel) >> >> b) a link between the prototypes and individuals (gr:hasMakeAndModel) >> >> So you can use common abstractions (e.g. pto:Laser_printer) for all >> of them while being able to keep them apart when needed by using >> the intersection of one of the three classes with the respective >> generic abstraction: >> >> foo:MyLaserPrinter a pto:Laser_printer, gr:ActualProductOrServiceInstance ; >> gr:serialNumber "123445X233"^^xsd:string . >> >> foo:ProtypeForALaserprinter a pto:Laser_printer, gr:ProductOrServiceModel ; >> color "black" . >> >> Now, if we know that foo:ProtypeForALaserprinter is the prototype >> for foo:MyLaserPrinter via >> >> foo:MyLaserPrinter gr:hasMakeAndModel foo:ProtypeForALaserprinter . >> >> we can infer that it will have the color "black", unless we have >> information about the specific color of foo:MyLaserPrinter. >> >> The actual reasoning for the defaults is beyond OWL DL, but can be >> well modeled e.g. in SPARQL CONSTRUCT rules: >> >> (from >> http://www.ebusiness-unibw.org/wiki/GoodRelationsOptionalAxiomsAndLinks#Product_Models): >> >> >> # Products inherit all product features from their product models >> unless they are defined for the products individually >> >> CONSTRUCT {?product ?property ?valueModel.} >> WHERE >> { >> { >> {?product a gr:ActualProductOrServiceInstance.} >> UNION >> {?product a gr:ProductOrServicesSomeInstancesPlaceholder.} >> } >> ?model a gr:ProductOrServiceModel. >> ?product gr:hasMakeAndModel ?model. >> ?model ?property ?valueModel. >> { >> {?property rdfs:subPropertyOf gr:qualitativeProductOrServiceProperty.} >> UNION >> {?property rdfs:subPropertyOf gr:quantitativeProductOrServiceProperty.} >> UNION >> {?property rdfs:subPropertyOf gr:datatypeProductOrServiceProperty.} >> } >> OPTIONAL {?product ?property ?valueProduct.} >> FILTER (!bound(?valueProduct)) >> } >> >> So if foo:MyLaserPrinter does not have a gr:color property, the >> rule will add >> >> foo:MyLaserPrinter gr:color "black" . >> >> Otherwise, it will preserve the local value. >> >> Quite clearly, an RDF dataspace can only do this once the set of >> relevant triples is defined; no true OWA. >> >> While this was initially designed for the pretty narrow case of >> commodities and their datasheets, it can also be used for other >> pairs of individuals and prototypes, e.g. a composition and its >> performance (think of the duration of a piece of piano music). >> Also, the common abstraction for both may differ (e.g. the >> prototype could be a foo:Oil_painting and the individual a >> foo:Picture) or be pretty broad (e.g. foo:DVD). >> >> >> Martin >> >> >> (thinking-out-loud alert) >> >> So this is a conversation that resurfaces over the years in various >> ways. My latest prompt being a combination of (i) seeing >> >> http://www.productontology.org/ >> which declares OWL DL classes (ie. >> classes of thing, aka types...) for commonly named products, using >> Wikipedia data. The product ontology site uses OWL to describe classes >> of largely mass-produced thing: >> >> "This service provides GoodRelations-compatible OWL DL class >> definitions for ca. 300,000 types of product or services that have an >> entry in the English Wikipedia, e.g. >> >> >> http://www.productontology.org/doc/Apple >> http://www.productontology.org/doc/Laser_printer >> http://www.productontology.org/doc/Manure_spreader >> http://www.productontology.org/doc/Racing_bicycle >> http://www.productontology.org/doc/Soldering_iron >> http://www.productontology.org/doc/Sweet_potato >> >> >> Back at DC-2008 in Berlin someone (maybe Karen Coyle or Diane Hillman) >> mentioned that a difference between libraries and museums is that the >> works collected by the former are mass produced. >> >> I think we can go some way towards webbifying FRBR by pondering that >> observation. I spent monday and tuesday with VU.nl colleagues visiting >> the Amsterdam Museum and then the Fab Lab at >> http://fablab.waag.org/ >> >> which showed some possibilities for taking museum artifacts and >> replicating lossy copies of them (with 3d printers and other >> mechanical reproduction techniques). We could even fabricate moulds >> derrived from artifacts that allow others to create new derrived >> instances (or their own moulds). Each generation derriving >> characteristics from the previous, and adding in its own flaws and >> innovations. >> >> Looking at the Product Ontology examples above, they work better at >> describing mechanically reproduced, near-identical artifacts - >> Laser_printer, Soldering_Iron than with the natural kinds of thing - >> apple, potato etc. Both apple and sweet potato are halfway to being >> mass nouns --- you might often have need to describe 'some' apple or >> sweet-potato, rather than 'a' sweet potato, although of course you can >> have a specific apple or potato in-hand. Mass production brings with >> it the prospect of thousands of *near*-identical instances of some >> type, as well as associating those with codes and lately URLs that >> link us back to information about the recipe or ingredients list for >> those types of thing. For complex modern mass produced items, if you >> know what kind of item it is, you know a huge amount about that thing >> - whether it is a book or a printer or a soldering iron. >> >> If we forget the library and cultural heritage scene for now, and >> think just about these product types: I have here in my room a >> specific laser printer. It is an HP Laser Smart C4270. Let's say it >> was bought in Leiden, Netherlands and has an owner (this household). >> It has specific characteristics local to this copy, as well as >> stereotypical characteristics that it shares with all other "HP Laser >> Smart C4270s". >> >> FRBR isn't designed to describe that kind of situation (although the >> parallels should be clear). But RDF and OWL do try to address that >> general case: RDF/RDFS/OWL is very much in the business of drawing >> such class-instance distinctions. OWL also goes some basic way towards >> providing information-machinery for stating generalisations about all >> the members of some class of thing. However OWL itself avoids certain >> complex topics that are relatively hard to avoid for us: it does not >> directly give us a way of saying '"typically". It does not give us a >> way of distinguishing intrinsic versus accidental properties. The >> latter saved W3C from retreading thousands of years of philosophical >> debate. The former is perhaps a medium-sized nuisance. Regardless: >> >> We can think of the class of things in the world that are *printers*. >> We can name that class with a URI and publish a description there. >> We can think of the class of things in the world that are *laser >> printers*. We can name that class with a URI and publish a description >> there. >> We can think of the class of things in the world that are *HP laser >> printers*. We can name that class with a URI and publish a description >> there. >> We can think of the class of things in the world that are *HP Laser >> Smart C4270 printers*. We can name that class with a URI and publish a >> description there. >> >> We can associate any thing in the world with one of more of these >> classes; in RDF by asserting an rdf:type relationship to the class. We >> can use properties associated with the class to describe the >> individual thing 'by hand', or we can draw factual conclusions about >> properties of some individual from general knowledge that makes claims >> about all members of a class. >> >> We can go deeper, towards query-like classes, and name the sub-class >> of HPLaserSmartC4270-Printer that corresponds to such printers bought >> in Leiden; or owned by me. Or that have a damaged scanner lid and >> which still serve adequately as a printer. Or which belong to the >> subclass manufactured in the UK and that shipped with a UK-compatible >> power cable. >> >> OWL doesn't impose any appropriate level of detail on us, it just >> provides descriptive primitives that let us talk in terms of [broadly] >> sets of things, the properties that characterise those sets, and the >> subset / superset relations between those sets. (We say class instead >> of set, and leave that distinction aside for now.) >> >> Computerised ontology languages like OWL are obsessed with this >> class-vs-instance distinction, and in modern mass produced life, the >> distinction is all around us, as are near-identical, mechanically >> reproduced copies of products - regardless of whether the product was >> designed to inform, educate, entertain, or remove unsightly nasal >> hair. >> >> Our FRBR-inspired conversations here are outshadowed by the need to >> make equivalent distinctions in other aspects of everyday life. From >> tracking down a replacement cable or scanner lid for my printer, to >> finding the nearest open shop that will sell me a certain kind of >> soldering iron on a sunday, or a certain DVD of a certain film, the >> desire to organize information in a way that mirrors the patterns of >> similarity amongst mass produced items is a modern universal. >> >>> From >> http://www.marxists.org/reference/subject/philosophy/works/ge/benjamin.htm >> http://en.wikipedia.org/wiki/The_Work_of_Art_in_the_Age_of_Mechanical_Reproduction >> >> and unfairly out of context, >> >> "In principle a work of art has always been reproducible. Man-made >> artifacts could always be imitated by men. Replicas were made by >> pupils in practice of their craft, by masters for diffusing their >> works, and, finally, by third parties in the pursuit of gain. >> Mechanical reproduction of a work of art, however, represents >> something new." [...] "With the woodcut graphic art became >> mechanically reproducible for the first time, long before script >> became reproducible by print. The enormous changes which printing, the >> mechanical reproduction of writing, has brought about in literature >> are a familiar story. However, within the phenomenon which we are here >> examining from the perspective of world history, print is merely a >> special, though particularly important, case." >> >> All I'm suggesting here is that we follow this advice from Walter >> Benjamin in 1936 and indulge ourselves in the idea that modeling >> bibliographic mass production is merely a special (and important) >> case. >> >> FRBR's "items" are the most concrete, tangible entities in the FRBR >> universe. In the physical realm they are things you might hold in your >> hand, put in a box, find at some location. The idea extended to the >> digital realm is naturally more ephemeral but we do at least have >> correspondingly objective characterstics that ground digital objects >> in clear ways: notions such as sizeInBytes, cryptographic hashes >> (sha1sum, md5) can be used to talk precisely about specific sequences >> of 'Zeros' and 'Ones'. >> >> Looking up the FRBR hierarchy at the more general notions of >> "Manifestation", "Expression" and "Work", these are FRBR's particular >> story for organizing our millions of items into sensible groups. >> FRBR's "work" notion is described textually as a “distinct >> intellectual or artistic creation.”... a kind of ghostly but specific >> entity, a kind of social fiction that acts as a descriptive (and >> sometimes legal) hub for organizing clusters of related items. >> "Expression" brings that somewhat down to earth (“the specific >> intellectual or artistic form that a work takes each time it is >> ‘realized.’”), while "Manifestion" finally articulates it in terms >> sets/classes rather than individual abstract entities: " “the physical >> embodiment of an expression of a work. As an entity, manifestation >> represents all the physical objects that bear the same >> characteristics, in respect to both intellectual content and physical >> form.”". >> >> So the distinctions made in terms of these *4* notions are similar to >> those baked into the core of RDF itself.... specific fairly concrete >> things organized into groups (sets, classes). RDF only allows itself >> 'rdf:type' and 'rdfs:subClassOf' relationships as a basis to describe >> all this. >> >> So if we go with this idea that "print is merely a special, though >> particularly important, case" of mass produced work, and that is it >> worth investigating RDF descriptive habits that address >> characteristics of mass production regardless of whether we are >> talking about bicycles, books, laser printers or farmyard equipment, >> ... where does this leave us? where does it get us? >> >> 1. We bring more clearly into scope some industrialised areas of >> cultural 'content' -- music, tv, films; >> http://musicontology.com/ >> http://www.bbc.co.uk/ontologies/programmes/2009-09-07.shtml >> ... areas >> where FRBR is a close but not perfect fit, and class-based models >> drift towards being 'FRBR-inspired' rather than 'FRBR-based'. >> >> 2. We find OWL lacks certain conventions for distinguishing >> stereotypical instances from flawed/accidental characteristics of >> actual instances. For eg. a copy of a some book I have on my desk >> might be missing a certain page, so its literal 'number of pages' >> property couldn't be inferred from a common class shared with other >> such manifestations of the same abstraction. Or the local adjustments >> made here to my printer (I swapped the power cable, or repaired the >> lid). There is a big literature in KR about defaults and overrides and >> it's tricky to get right with open-world design of RDF/OWL/RDFS. >> >> 3. Works, Manifestations and Expressions might all just be kinds of >> classes; or annotations on classes. The class of *HP Laser Smart C4270 >> printers* of which I have one in this room; the class of *SQL and >> Relational Theory books* of which I have one on my desk as I type. The >> former is described at >> >> http://h10025.www1.hp.com/ewfrf/wc/product?cc=us&lc=en&dlc=en&product=3300222 >> >> by its maker; the latter at >> http://oreilly.com/catalog/9780596523084 >> >> ... more general classes might be tagged 'work-class'; very precise >> classes tagged 'manifestation-class'. But fundamentally we get a huge, >> universal spectrum (from the class of 'every Thing', to the class of >> 'No-thing') rather than forcing each into one of the FRBR 4. >> >> In both these example cases, there are product codes and online >> databases, and other people who own different instances of the same >> kind of thing. In both cases there are related products (maybe an >> ebook, maybe a successor printer design, or ink cartridge) where >> information at the level of 'all products' is useful to the owners and >> custodians of specific products. >> >> 4. OWL 2.0's punning mechanism may be relevant. This is a trick in OWL >> 2 that lets a single URI serve both as a class identifier (the class >> of C4270printers) but also as an identifier at the instance level, eg. >> something that might have other data attached like images or links to >> product documentation. >> >> 5. We would effectively be abandoning the attempt to fit the >> bibliographic universe into 4 buckets, and allowing different parties >> to name and describe classes at any level of generality, picked out by >> the properties of the things in that class. I might care to name a >> class for all books written by all former pupils of the school >> described at >> http://en.wikipedia.org/wiki/RGS_High_Wycombe >> --- this >> class would include SQL and Relational Theory, via its author, >> >> http://dbpedia.org/page/Christopher_J._Date >> .... or you might care to >> create a class for products whose primary inventor was an immigrant. >> By stepping back from the FRBR 4, we could get a more free-form >> environment in which properties of all kinds of thing can be used to >> define whatever classes are useful. >> >> 6. What does this mean in terms of 'who defines what when' metadata >> practice? If the abstract work "SQL and Relational Theory" by C.J.Date >> is in some sense now an RDF class, what should the URI be? Who >> publishes it and what practice should exist around the associated >> online description? I don't know. Maybe authors, publishers and >> libraries all have a role, ... maybe there are 3 or more >> semi-competing URIs for that class, one from C.J.Date, one from the >> publisher O'Reilly or one or more from a library perspective. Perhaps >> one of these descriptive agencies ends up playing a hub role and >> including links to further description of the class from the other >> parties. Maybe practices vary between fields and types of product. I >> really don't know. And the core RDF/OWL specs are not the kinds of >> thing that will tell us what's best to do, btw. >> >> 7. What kinds of thing are properly expressed at the class level? I >> also don't know. We might find value in rethinking some properties to >> more explicitly attach them to the stereotypical ideal member of some >> class, as a way of admitting that not all instances will match the >> ideal. Perhaps for eg. the idea that books have 'numPages' could be >> defined to refer to the stereotypical ideal case, even while applied >> at the instance level. So if I lose 5 pages from the copy of "SQL and >> Relational Theory" on my desk, we still say it has 410 numbered pages. >> Maybe we go through and think 'which properties does it even make >> sense to mutate at the instance level?". For all the damage I could do >> to my copy of that book, I'm not going to change its author or >> subject, for example. So those would be readily expressed in terms of >> OWL. The numPages could be expressed as an OWL generalisation about >> all instances if we define that property to be the ideal number, >> rather than having to track damaged pages etc. And some properties >> such as geographic location or owner make sense only at the instance >> level. A few of these (such as e.g. initialOwner) might be static >> properties that never change their value; others vary from time to >> time. >> >> >> Ok this post is too long already. Another way of stating all this is >> that it's an appeal to think more in terms of specific >> somehow-concrete items, things. Artifacts in your hand, or computer >> data files that might be checksummed. And that all abstractions above >> those are means to an end, rather than ends in themselves. So we can >> ask whether, instead of pondering the vague characteristics of ghostly >> entities like 'works', 'expressions' and 'manifestations', whether >> we're simply talking about the common characteristics of collections >> of identifiable *items*. And if that is what we're doing, whether (a) >> we can more explicitly share common descriptive practices with other >> non-textual mass produced kinds of things (b) whether RDF/OWL might >> have some built-in facilities that could be used more (ie. its notion >> of class). >> >> This all wouldn't abolish the WEMI distinctions, rather they would as >> sketched above, show up as a kind of annotation on RDF classes. Some >> classes might be work-ish classes; the class of all Hamlets. Others >> might be manifestation-ish classes; the class of all paper-printed >> first edition SQL and Relational Theory copies. But the core >> organising idea is sets/classes rather than the ghostly upper entities >> of FRBR. Aspects of those entities would also show up as concrete >> documents; an artists first sketches of a later painting; CJ Date's >> book contract with O'Reilly that gave us the later book. First, second >> and final drafts; hp printer schematics, blueprints; architectural >> drawings; bike designs; ingredient lists and working notes. But rather >> than merge our knowledge about all those practical things into the >> vaguer composite entities of FRBR we just itemise them and describe >> them as plain old artifacts at the instance level - giving us >> something like a catalogue of evidence left in the world that shadows >> the creative process, rather than reifying the act of creation into >> special 'things' that can be described but never touched, used, read >> or consumed. >> >> Hope this all makes some sense. Related discussion from Bradley Allen, >> Karen and others: >> >> >> http://bpa.tumblr.com/post/10814190/faceted-classification-and-frbr >> http://www.mail-archive.com/rda-l@listserv.lac-bac.gc.ca/msg03837.html >> http://www.mail-archive.com/rda-l@listserv.lac-bac.gc.ca/msg03848.html >> http://bibwild.wordpress.com/2007/12/07/frbr-considered-as-set-relationships/ >> http://lists.w3.org/Archives/Public/public-owl-dev/2008JulSep/0110.html >> http://lists.w3.org/Archives/Public/public-lld/2010Sep/0049.html >> >> >> cheers, >> >> Dan >> >> ps. I tried to draw some of this out graphically: >> >> http://www.flickr.com/photos/danbri/2891150205/ >> ... story of a >> t-shirt design as frbr-inspired classes >> >> http://www.flickr.com/photos/danbri/2892286406/in/photostream/ >> ...same >> story as a timeline >> >> Received on Thursday, 17 March 2011 11:45:15 GMT >> • This message: [ Message body ] >> • Previous message: Young,Jeff (OR): "RE: Ontological constraints" >> • Mail actions: [ respond to this message ] [ mail a new topic ] >> • Contemporary messages sorted: [ by date ] [ by thread ] [ by >> subject ] [ by author ] >> • Help: [ How to use the archives ] [ Search in the archives ] >> This archive was generated by hypermail 2.2.0+W3C-0.50 : Thursday, >> 17 March 2011 11:45:16 GMT >> > > > -- Karen Coyle kcoyle@kcoyle.net http://kcoyle.net ph: 1-510-540-7596 m: 1-510-435-8234 skype: kcoylenet
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