- From: Young,Jeff (OR) <jyoung@oclc.org>
- Date: Sun, 28 Aug 2011 11:11:58 -0400
- To: "Antoine Isaac" <aisaac@few.vu.nl>, <public-xg-lld@w3.org>
I'm comfortable with the diff. Thanks Antoine. Jeff > -----Original Message----- > From: public-xg-lld-request@w3.org [mailto:public-xg-lld- > request@w3.org] On Behalf Of Antoine Isaac > Sent: Sunday, August 28, 2011 10:07 AM > To: public-xg-lld@w3.org > Subject: Re: References to "application profiles" > > Hi everyone, > > It seemed difficult to extract a consensus from the thread :-) > Anyway I've tried: > http://www.w3.org/2005/Incubator/lld/wiki/index.php?title=Draft_Vocabul > aries_Datasets_Section2&diff=6006&oldid=5906 > > As APs are already mentioned in this section (and I understand Tom > would add them in other parts of the report) I have removed them from > the debatable sentence. And I've tried to make my "gradation" more > explicit, while not presenting it as a formal framework. > Btw "alignments" do indeed include ontology mappings as expressed in > OWL, clearly. > > Cheers, > > Antoine > > > > Quoting "Young,Jeff (OR)" <jyoung@oclc.org>: > > > > > >> I'm uncomfortable using the term AP even for situations where a > variety > >> of existing classes and properties are getting reused. An OWL > ontology > >> can be created to document this situation, even if no new terms are > >> being defined there. > > > > I agree with Jeff here. It seems that AP is being used for any > ontology that uses a mix of namespaces or that adopts properties from > existing namespaces. This seems to me to be normal practice for > ontology development. At what point does a choice of properties become > an AP? In DC terms, I think that it becomes an AP only when constraints > are added (mandatory, optional, repeatable or not, etc.). > > > > I commonly hear people use the term AP when someone consciously > creates a personalized or modified version of a known metadata schema. > So a sub-set of, say, MARC that selects out the fields needed to encode > music resources but not cartographic resources would be an AP in this > definition. > > > > Basically, I think we don't have a clear enough definition of AP to > use the term in this report without going through a lengthy discussion > that would allow us to make it clear. I'd prefer to leave it out, but > think that the concept is important and definitely needs more thought. > > > > kc > > > >> Granted, you don't see much of that happening yet, > >> but presumably that's presumably because people are still trying to > wrap > >> their minds around OWL in general. > >> > >>> But there are many situations in which re-using a > >>> vocabulary comes with risks/costs that could motivate coining one's > >> own > >>> "duplicate" elements. Consider what schema.org did: they just > prefered > >>> to coin all the elements they need, rather than spend time shopping > >>> around for existing elements--which may be not well maintained > anyway. > >>> That's maybe not the best practice around, but that will continue > to > >>> happen. In such cases, establishing alignments between element sets > is > >>> a lesser evil. > >> > >> As a species, I think we are still beginners in terms of modular > >> thinking. I can't think of a single existing model or set of models > that > >> doesn't make me squirm and shake. "Alignments" or "mappings" give me > >> hope that we will be able to adapt regardless. > >> > >>> > >>> The "gradient" of best practice here would be: (1) own duplicate > >>> element sets with no alignment; (2) own element sets with alignment > to > >>> existing vocabularies (3) "true" APs with re-use of existing > >>> vocabularies. > >> > >> I agree with these idealized gradients with a couple of caveats. > >> > >> 1) Existing vocabularies that don't conform to best practice recipes > >> suck: http://www.w3.org/TR/swbp-vocab-pub/ > >> 2) Some existing vocabularies (even popular ones) can be very weird > and > >> arguably would be better off being mapped > >> 3) The ability to transform domain-specific vocabularies into > foreign > >> vocabularies shouldn't be that far off if the mappings exist > >> > >>> > >>> I'm not saying that it was clearly worded here, far from it :-) > >>> I can also live with this point being mentioned in another section. > >> But > >>> I wanted to warn against making this disappear, altogether. > >> > >> I suspect that all these thoughts are too controversial to used on > short > >> notice, though. > >> > >> Jeff > >> > >>> > >>> Cheers, > >>> > >>> Antoine > >>> > >>> > Dear all, > >>> > > >>> > Re-reading the paragraph in [1]: > >>> > > >>> > A similar concern can be voiced regarding metadata element > >> sets. > >>> As > >>> > testified in the Linked Open Vocabularies inventory, > >>> practitioners > >>> > generally follow the good practice of re-using existing element > >>> sets or > >>> > building "application profiles" of them. And some projects, > >> such > >>> as the > >>> > Vocabulary Mapping Framework, aim at supporting that process. > >>> But the lack > >>> > of long-term support for them threatens their enduring meaning > >>> and common > >>> > understanding. Further, some reference frameworks, notably > >> FRBR, > >>> have been > >>> > implemented in different RDF vocabularies, which are not always > >>> connected > >>> > together. Such situation lowers the semantic interoperability > >> of > >>> the > >>> > datasets expressed using these RDF vocabularies. The community > >>> should > >>> > encourage the coordinated re-use of element sets for particular > >>> entity > >>> > descriptions, their extension through, e.g., application > >>> profiles, or their > >>> > alignment using, e.g., semantic relations from RDFS and OWL. > >>> Here, we hope > >>> > that better communication between the creators and maintainers > >>> of these > >>> > resources, as encouraged by our own incubator group or the LOD- > >>> LAM > >>> > initiative, will help to consolidate the conceptual connections > >>> between > >>> > them. > >>> > > >>> > ...where "a similar concern" refers to "semantic links across > value > >>> vocabularies". > >>> > > >>> > Looking closer: > >>> > > >>> >> A similar concern can be voiced regarding metadata element sets. > As > >>> >> testified in the Linked Open Vocabularies inventory, > practitioners > >>> >> generally follow the good practice of re-using existing element > >> sets > >>> or > >>> >> building "application profiles" of them. > >>> > > >>> > If we mean Dublin-Core-style application profiles (as Singapore > >>> Framework is > >>> > cited further on in the paragraph), then we could say something > >> like: > >>> > > >>> > A similar concern can be voiced regarding metadata element > >>> sets. As > >>> > testified in the Linked Open Vocabularies inventory, > >>> practitioners > >>> > generally follow the good practice of re-using existing > >> element > >>> sets or > >>> > building "application profiles" that re-use elements from > >>> multiple sets. > >>> > > >>> > Then, I do not really understand the first part of this sentence: > >>> > > >>> >> The community should encourage the coordinated re-use of element > >>> sets for > >>> >> particular entity descriptions, their extension through, e.g., > >>> application > >>> >> profiles, or their alignment using, e.g., semantic relations > from > >>> RDFS and > >>> >> OWL. > >>> > > >>> > The phrase "encourage the coordinated re-use of element sets for > >>> > particular entity descriptions" seems to be saying something > like: > >>> > > >>> > ...promote the use of common patterns of mixing vocabularies > >> for > >>> > describing particular types of things. > >>> > > >>> > However, I do not think this reference to application profiles > >> really > >>> belongs > >>> > in a section on alignment. > >>> > > >>> > Rather, I would like to propose the following: > >>> > > >>> > -- That the section "The linking issue" (vague, because the whole > >> LLD > >>> XG report is > >>> > arguably about a "linking issue") be renamed something like: > >>> > > >>> > Semantic alignment > >>> > > >>> > -- In this case, the first sentence -- "Many semantic links > across > >>> value > >>> > vocabularies are already available..." -- could be preceded with > >>> a definition > >>> > along the lines of: > >>> > > >>> > "Alignments" are links between semantically equivalent, > >>> similar, or > >>> > related terms or entities across different value > >>> vocabularies, metadata > >>> > element sets, or datasets. > >>> > > >>> > -- The notion of application profiles is more appropriately > >>> referenced in the point > >>> > about re-using patterns: > >>> > > >>> > In the paragraph: > >>> > > >>> > Design patterns allow implementers to build on the experience > >> of > >>> > predecessors. Traditional cataloging practices are documented > >>> with a rich > >>> > array of patterns and examples, and best practices are starting > >>> to be > >>> > documented for the Linked Data space as a whole (e.g., > >>> > <ref>http://linkeddatabook.com/editions/1.0/#htoc61</ref>). [*] > >>> What is needed > >>> > are design patterns specifically tailored to LLD requirements. > >>> Such design > >>> > patterns would meet the needs of people and developers who > >>> understand new > >>> > techniques through patterns and examples and will increase the > >>> coherence of > >>> > Library Linked Data overall. > >>> > > >>> > I propose inserting a sentence: > >>> > > >>> > Application profiles > >> (http://dublincore.org/documents/singapore- > >>> framework/) > >>> > provide a method for a community of practice to document and > >>> share patterns > >>> > used for describing specific types of materials. > >>> > > >>> > -- ...and application profiles are also relevant to "data design" > >>> [2]: > >>> > > >>> > Another boost for Linked Data is the growing use of OWL for > >>> purposes of > >>> > data design. Prior to OWL, domain experts could use RDFS to > >>> create metadata > >>> > element sets, but there was no way to map equivalencies across > >>> > vocabularies. Among other features, OWL includes an upgrade to > >>> RDFS to > >>> > support ontology mapping. This allows experts to describe their > >>> domain > >>> > using community idioms, while still being interoperable with > >>> related or > >>> > more common idioms. A variety of tools related to OWL can be > >>> found on the > >>> > W3C's RDF wiki and OWL wiki. Unified Modeling Language (UML) > >>> tools are also > >>> > value to help designers represent and manipulate domain models > >>> visually. > >>> > The Ontology Definition Metamodel (ODM) specification should > >>> help bridge > >>> > some of the gaps between UML and OWL. [*] > >>> > > >>> > I propose to add: > >>> > > >>> > Application profiles > >> (http://dublincore.org/documents/singapore- > >>> framework/) > >>> > provide a way to specify how a community of practice defines a > >>> > domain model and re-uses specific vocabularies in order to > >>> create metadata > >>> > conforming to a particular pattern. > >>> > > >>> > Tom > >>> > > >>> > [1] > >>> > >> > http://www.w3.org/2005/Incubator/lld/wiki/DraftReportWithTransclusion#T > >>> he_linking_issue > >>> > [2] > >>> > >> > http://www.w3.org/2005/Incubator/lld/wiki/DraftReportWithTransclusion#T > >>> ools_for_data_designers > >>> > [3] > >>> > >> > http://www.w3.org/2005/Incubator/lld/wiki/DraftReportWithTransclusion#D > >>> evelop_and_disseminate_best- > practices_design_patterns_tailored_to_LLD > >>> > > >>> > > >>> > >>> > >> > >> > >> > >> > > > > > > > >
Received on Sunday, 28 August 2011 15:12:57 UTC