- From: Karen Coyle <kcoyle@kcoyle.net>
- Date: Wed, 03 Jul 2013 21:03:05 -0700
- To: Niklas Lindström <lindstream@gmail.com>
- CC: "public-schemabibex@w3.org" <public-schemabibex@w3.org>
On 7/3/13 2:12 PM, Niklas Lindström wrote: > Karen, > > On Wed, Jul 3, 2013 at 10:47 PM, Karen Coyle <kcoyle@kcoyle.net > <mailto:kcoyle@kcoyle.net>> wrote: > > Once again, good idea, but a different meaning. > > > That's exactly my point. I elaborated on that, suggesting that the > *combination* of 'isFormatOf' and 'isVersionOf' may cover what > 'commonEndeavor' is after. And that I value this distinction (as defined > in DC), because its meaning has been proven useful. Niklas, are you implying that one would use two triples to describe a single relationship? In a world of triples, I'm just not sure what a "combination of" two properties might mean. > > > As I said, 'isVersionOf' implies precedence, but only a temporal > precedence. It can most definitely relate two "manifestations", such as > a legal document and a revision of it. It links to another "version, > edition, or adaptation", with "substantive changes in content rather > than differences in format". I don't know of anything in DC's "isVersionOf" that implies a temporal precedence, although that may be a common usage. For example, United Nations documents are published simultaneously in multiple languages, and they are definitely versions of each other, but there is no temporal precedence. It does imply a change of some sort (like being in different languages), and commonEndeavor does not require that there be a change in the resource content. It can be two publications of the same text. I would be open to a broader interpretation of dc:isVersionOf except for the note on that property that reads: "Changes in version imply substantive changes in content rather than differences in format." That "substantive changes in content" is the key point. >. > > > I understand that. I also brought up 'dcterms:relation' (defined as "A > related resource", and being the explicit superproperty of > 'dcterms:isFormatOf' and 'dcterms:isVersionOf'), which may fit this use > case (albeit being even more general). Just like 'commonEndeavor', it is > (reasonably) a symmetric and transitive property. Yes, dc:relation is very much along the same lines, although it doesn't specify that there is common intellectual content. It is defined as "A related resource." I do wish that the definition were a bit clearer, or that there were examples. Would it include two different monographs in a monographic series? Two books by the same author (but totally different in content)? If it doesn't imply a commonality of content then it seems to be not terribly useful. Of course anyone could say that resourceA -> dc:relation -> resourceB. But that wouldn't be recognized as being part of schema.org, which has to be in the schema.org namespace, so I'm not sure what the relevance of the dc properties are to our discussion. If we want resource relationships to be recognized by schema.org we need to define them in schema.org, right? kc > > Cheers, > Niklas > > > kc > > > > On 7/3/13 11:47 AM, Niklas Lindström wrote: > > Hi Karen, > > Thanks! Yes, that is an important point – 'commonEndeavor' is less > specific than 'isFormatOf'. However, Dublin Core also defines > 'dcterms:isVersionOf' [1], as: > > A related resource of which the described resource is a > version, > edition, or adaptation. > > Changes in version imply substantive changes in content > rather than > differences in format. > > Combined, I believe they can cover the gamut of use cases. And > the good > thing with that is that this specificity, which is already > well-known > thanks to the widespread use of DC, makes the resulting descriptions > more actionable, in my opinion. Thinking of queries, and user > interfaces > thereof, it seems to me that it is rather common to differ between > either various versions of a work, or various formats > (representations) > thereof. (Of course, provided that the statement about what > constitutes > a version or format is made by an informed party with knowledge > about > the work in question.) > > So to cover (more of) what we're after, the 'isFormatOf' suggestion > should be combined with 'isVersionOf', to enable differentiation on > these aspects. > > As for precedence, 'isVersionOf' does imply that. Not so much with > 'isFormatOf', although it might be more apt for relating something > specific to something general. It is not required though, as > long as the > substantial content is the same. I don't know enough about use cases > where a generic relation between things that are based on a common > endeavor is suitable, so I cannot readily speak for the aptness > of these > properties there. Relating a book and a movie in general, without > stating that one is derived from the other (which I'd gather is the > common case), seems to imply that they are about the same topic. For > relating to what they are about, we have 'schema:about' (with > say a link > to a DBPedia resource for the topic at hand). For stating that a > movie > is an adaptation of a book, I believe 'dcterms:source' [2] is > applicable. (More so than 'isVersionOf' since the change is > substantive > in format as well. In any case, I do not think they represent > the same > creative work, and therefore do not constitute alternate formats > of each > other.) > > As for relating e.g. a movie and a book together without > specifying that > relation further, 'dcterms:relation' [3] might be fine, since > that is > very general indeed. Both 'dcterms:isFormatOf' and > 'dcterms:isVersionOf' > are subproperties of that one. If you want to group a bunch of > related > works together, that would apply. Another interesting DC term is > 'dcterms:references' [4]. > > (Regarding 'dcterms:source', if that were to be incorporated into > schema.org <http://schema.org> <http://schema.org>, it'd have to > be renamed, since that > > one's already defined in [5] – as "The anatomical or organ > system that > the artery originates from", of all things.. I'd suggest > 'isBasedOn', as > a corresponding ObjectProperty to the already defined > 'schema:isBasedOnUrl', which is rather poor..) > > As mentioned, I think we should seriously consider all of these, > since > Dublin Core has been successfully deployed for many years. And > even if > we end up with modified versions of them, and/or something in > between > (such as 'commonEndeavor'), I think it is very valuable to be > able to > state, as succinctly as possible, how our resulting proposals > relate to > the DC terms. (And by succinctly, I personally mean using RDFS/OWL.) > > On that topic, a related, interesting read is the "Dublin Core > to PROV > Mapping" WG Note [6], which explains in-depth correlations > between the > W3C PROV (provenance) vocabulary and the above mentioned DC > terms (among > others). > > Finally, I believe that many participants in the "DCMI Schema.org > Alignment Task Group" [7] are also members of this group, > correct? From > my point of view, we should be doing the same thing, more or > less. If > this other group is still active, I wonder if we could merge our > efforts? > > Cheers, > Niklas > > [1]: http://purl.org/dc/terms/__isVersionOf > <http://purl.org/dc/terms/isVersionOf> > [2]: http://purl.org/dc/terms/__source > <http://purl.org/dc/terms/source> > [3]: http://purl.org/dc/terms/__relation > <http://purl.org/dc/terms/relation> > [4]: http://purl.org/dc/terms/__references > <http://purl.org/dc/terms/references> > [5]: http://schema.org/Artery > [6]: http://www.w3.org/TR/prov-dc/ > [7]: http://wiki.dublincore.org/__index.php/Schema.org_Alignment > <http://wiki.dublincore.org/index.php/Schema.org_Alignment> > > > > On Wed, Jul 3, 2013 at 12:36 AM, Karen Coyle <kcoyle@kcoyle.net > <mailto:kcoyle@kcoyle.net> > <mailto:kcoyle@kcoyle.net <mailto:kcoyle@kcoyle.net>>> wrote: > > Niklas, while your proposal is very well thought-out, let > me clarify > that "commonEndeavor" is not the same as dc:isFormatOf. > commonEndeavor can be between things of the same format, > such as the > same text published at different times (e.g. the many > re-publications of various classics). Another possibility > is to use > it to link translations to each other (even though none are the > original). It can ALSO refer to the same story or theme in > different > formats. In other words, commonEndeavor is broader than > dc:isFormatOf, and can be used for anything where you think the > intellectual font was the same. > > What I like about commonEndeavor is that it does not assume a > precedence. I realize that in fact saying that MovieA > dc:isFormatOf > BookB does not state that the book can first, but I think > it is easy > to interpret it that way. commonEndeavor is designed to be a > horizontal relationship that says, in effect: the two of > these have > significant intellectual content in common. > > None of this is to say that we should NOT also consider > dc:isFormatOf if we consider it useful. It's just that it has a > different meaning to commonEndeavor. > > I agree with your analysis that it is best to avoid the > necessity of > an abstract class. I think that it is better to create > relationships > between things that people generally recognize as "things" > than to > try to decide what is abstract and what is concrete. Both > commonEndeavor and dc:isFormatOf avoid the need for an > abstract class. > > kc > > > On 7/2/13 2:54 PM, Niklas Lindström wrote: > > Hi all, > > I'm sure we can find a way of reconciling our current, > varied, > positions > regarding instanceOf and commonEndeavour. The > differences seem > to relate > to various MARC and FRBR experiences, or at least > reactions to the > different rigors, or indeed lack thereof, that have > come out of > these. I > also think we can avoid inventing too much new thinking > on these > matters, since there is lots to reuse from the domain > of resource > descriptions. > > Model-wise, I think many of us (perhaps all) agree that the > restrictive > abstraction principles of WEMI separation, and the > simpler but still > divided Work/Instance counterpart evolving in BIBFRAME, > are too > rigid > for schema.org <http://schema.org> <http://schema.org> > <http://schema.org/> (and > > possibly for cataloguing in > > general). However, many also see a great benefit in > relating to > common > generalized notions of works from their specific forms, > at least > when a > work is available in a multitude of formats. This > notion is very > useful > both for facilitating cataloguers' workflow and for > building > services > upon the data. As I mentioned a while ago [1], this is > not so > much about > *abstraction* but *generalization* (also elaborated on > in [2]). > So let > us neither prescribe nor prohibit. > > We should carefully consider what has been done in the > wild, and > especially practices stemming from, but not limited to, > libraries. A > good example of this is the Dublin Core Terms > vocabulary [3], > which has > been heavily used for many years now, in lots of linked > data > scenarios. > It is used in and recommended by many W3C specs (e..g > SKOS, VoID and > PROV) and is the base for many community vocabularies, > such as > BIBO. Its > terms are used in lots, if not most, of the datasets in the > Linked Open > Data cloud. If there is any stable core in the plethora of > bibliographic > vocabularies, I'd say DC terms is it. And it gets by > with (probably > because of) quite a minimal specification (just like > schema.org <http://schema.org> > <http://schema.org> > <http://schema.org>). > > > I therefore suggest that we consider 'isFormatOf', > explicitly > based on > 'dcterms:isFormatOf' [4], as a replacement for, or indeed a > unification > of, both the 'instanceOf' and 'commonEndeavour' > proposals (and > possibly > content/carrier). > > Dublin Core defines 'isFormatOf' as: > > A related resource that is substantially the same > as the > described > resource, but in another format. > > The things being in specific formats are representations, > manifestations > or instances. This property can be used both to relate > between > different > formats (similar to 'commonEndeavour'), and for linking > from a > specific > format to a generalized notion, such as an expression > or work > (similar > to 'instanceOf'). The latter use of > 'dcterms:isFormatOf' is quite > common, using the pattern of linking different > representations > (e.g. in > HTML or PDF for digital representations, or hardcover or > paperback for > physical books) to a general resource which they represent. > Examples of > this can be seen e.g. in legislation.gov.uk > <http://legislation.gov.uk> > <http://legislation.gov.uk> <http://legislation.gov.uk> > > > [5]. (For specifying the kind of format, > schema:bookFormat is > applicable, as is the more general dcterms:format > property). > > As for the actual name, we could include 'isFormatOf' > as is (and > possibly its inverse, 'hasFormat'). Or we could relabel it > somehow. The > name is important, but only instrumentally so. The most > important thing > is to find a common meaning, and to do so we should > base it on > existing > usage. > > (I'd also like to note that the solid proposal we do > have on the > table, > 'hasPart'/'isPartOf', correlates very much to the existing > Dublin Core > properties of the same name (as has also been > discussed). I do > think we > should mention that in the wiki page. I can address > that unless > anyone > objects, following the pattern of the Datasets proposal > [6]. In > fact, if > we can find a common ground in (at least parts of) the > Dublin Core > terms, we can also continue to import some other terms, > such as > 'isVersionOf', 'references' and 'source', if needed.) > > Regarding the necessity of an abstract class, I don't > think it is a > strict requirement for this pattern. The notion of variable > generalization is already present in the fact that we don't > describe one > single item/copy even at the specific format level. > That is, even a > "manifestation" has the extent of a group, and thus we can > relate that > to a broader group representing the union of manifestations > (i.e. the > "expression" level), without needing to separate the > classes. This > notion seems very much present in the Product type as well, > where it's > up to the user of the vocabulary to determine the level of > specificity > for the subject described. Granted, there are additional > specializations > in IndividualProduct and ProductModel, but both derive > from the > general > Product class. Thus, there is no principal divide. (In > fact, if > a case > was made that there is, that would seem to be an > argument for the > applicability of WEMI in schema.org..) > > (The choice of which other properties (e.g. author, > illustrator, > subjects, publisher) should be specific to a certain > format/representation is then up to the data publisher > (cataloguer > and/or library system) to determine. You might do selective > copying of > properties, or link to a prototypical uniform work. > Consumers/services > wishing to index data for each specific format in their > entirety can > also copy in the general properties from the general form. > Others may > choose to traverse graphs, or even create unions of > related formats > altogether into a mixed form described with all > properties.) > > Cheers, > Niklas > > [1]: > http://lists.w3.org/Archives/____Public/public-schemabibex/____2013Mar/0077.html > <http://lists.w3.org/Archives/__Public/public-schemabibex/__2013Mar/0077.html> > > <http://lists.w3.org/Archives/__Public/public-schemabibex/__2013Mar/0077.html > <http://lists.w3.org/Archives/Public/public-schemabibex/2013Mar/0077.html>> > [2]: > http://grammar.ccc.commnet.____edu/grammar/composition/____abstract.htm > > <http://grammar.ccc.commnet.__edu/grammar/composition/__abstract.htm > <http://grammar.ccc.commnet.edu/grammar/composition/abstract.htm>> > [3]: http://purl.org/dc/terms/ > [4]: http://purl.org/dc/terms/____isFormatOf > <http://purl.org/dc/terms/__isFormatOf> > <http://purl.org/dc/terms/__isFormatOf > <http://purl.org/dc/terms/isFormatOf>> > [5]: > http://www.legislation.gov.uk/____developer/formats/rdf > <http://www.legislation.gov.uk/__developer/formats/rdf> > <http://www.legislation.gov.__uk/developer/formats/rdf > <http://www.legislation.gov.uk/developer/formats/rdf>> > [6]: http://www.w3.org/wiki/____WebSchemas/Datasets > <http://www.w3.org/wiki/__WebSchemas/Datasets> > <http://www.w3.org/wiki/__WebSchemas/Datasets > <http://www.w3.org/wiki/WebSchemas/Datasets>> > > -- > Niklas Lindström > National Library of Sweden (KB) > > > -- > Karen Coyle > kcoyle@kcoyle.net <mailto:kcoyle@kcoyle.net> > <mailto:kcoyle@kcoyle.net <mailto:kcoyle@kcoyle.net>> > http://kcoyle.net > ph: 1-510-540-7596 <tel:1-510-540-7596> <tel:1-510-540-7596 > <tel:1-510-540-7596>> > m: 1-510-435-8234 <tel:1-510-435-8234> <tel:1-510-435-8234 > <tel:1-510-435-8234>> > skype: kcoylenet > > > > -- > Karen Coyle > kcoyle@kcoyle.net <mailto:kcoyle@kcoyle.net> http://kcoyle.net > ph: 1-510-540-7596 <tel:1-510-540-7596> > m: 1-510-435-8234 <tel:1-510-435-8234> > skype: kcoylenet > > -- Karen Coyle kcoyle@kcoyle.net http://kcoyle.net ph: 1-510-540-7596 m: 1-510-435-8234 skype: kcoylenet
Received on Thursday, 4 July 2013 04:03:32 UTC