- From: Anthony Moretti <anthony.moretti@gmail.com>
- Date: Wed, 13 Jun 2018 20:24:39 -0700
- To: Dan Brickley <danbri@google.com>
- Cc: mfhepp@gmail.com, Sebastian Samaruga <ssamarug@gmail.com>, Simon Cox <Simon.Cox@csiro.au>, Peter Patel-Schneider <pfpschneider@gmail.com>, Richard Wallis <richard.wallis@dataliberate.com>, semantic-web@w3.org, public-schemaorg@w3.org
- Message-ID: <CACusdfRz4YCsz7LXjmGZJsmFt50CeS-F9jRbtpWfQ6zhZiy9QQ@mail.gmail.com>
Cheers Dan and Martin, I'll do as you said Dan and file these on GitHub and continue the discussion there. My motivation is that if Schema will be used for say one hundred years then even if it takes several years to introduce new vocabulary and slowly deprecate old vocabulary it will be worth it as consistency and correctness will help everybody in the long run (especially in ontologies where I think errors can propagate easily). I do iOS development and I see old Swift APIs deprecated all the time, a lot of it due to new API design guidelines <https://swift.org/documentation/api-design-guidelines/>, but millions of developers cope because it's done fairly planned. Because people might already be following the discussion here I want to address Martin's points quickly. I didn't analyze it before but it seems that IndividualProduct might exist because of another error; not all groups of products are products, so by the "some or all" test SomeProducts shouldn't be a subtype of Product, therefore IndividualProduct is equivalent to Product and can be removed. (An example is a group of products consisting of one product sold only in America, one product sold only in China, the group not being sold as an item.) Instead of: *Product* * IndividualProduct* * ProductModel* * SomeProducts* It could be simpler: *Product* *ProductType* *SomeProducts* Does that seem correct? I suggest ProductType not ProductModel because "Type" is the terminology in Schema's data model, so ideally that would be the default (it also seems more general, food "types" as opposed to food "models" for example). In any case, even if ProductModel refers not to product types but to datasheets not all datasheets are Products, so it also fails the some or all test and so probably shouldn't be a subtype of Product. Anthony On Wed, Jun 13, 2018 at 2:53 PM Dan Brickley <danbri@google.com> wrote: > > > On Wed, 13 Jun 2018 at 14:38, Martin Hepp <mfhepp@gmail.com> wrote: > >> Dear Anthony: >> >> I think I understand your motivation to clean up inconsistencies in >> schema.org. However, schema.org is a complex living thing and changes to >> existing elements come at high cost - broken markup, broken applications, >> developer confusion, etc. So in general we have been very, very reluctant >> to rename existing elements. >> >> The discussion you seem to carry out here implies very significant >> changes without a clear operational benefit. >> >> Keep in mind that any change would require updating all examples and all >> tooling. Plus, it will confuse developers because previously valid markup >> will render invalid. >> >> So I strongly discourage this approach. >> >> BTW, IndividualProduct is needed because you need to distinguish >> individual products from bags of identical products. >> >> ProductType is actually worse than ProductModel, because this is not for >> the type of a product, but for e.g. a datasheet, which is called a product >> model in many fields >> > > To add to what Martin says here, ... we are generally much more inclined > towards cleanup and improvements which don't make work for publishers, > webmasters and developers; e.g. in textual definitions, examples and so on. > There's also a lot of good work that could still be done in that direction. > While it is true that naming and other inconsistencies can add to the cost > of adoption and occasionally to publisher confusion, I'd argue that for the > vast majority of cases (i.e. the workflows that have resulted in > schema.org appearing in millions of sites, bazillions of pages, ...), the > publishers are working case-by-case in pursuit of specific documented > features from search engines and others, and generally focussed on a single > example rather than global vocabulary consistency. It is rare to run into > schema.org publishers who are agonizing over endurants and perdurants and > the ontological status of potential actions versus repeating events with > one-off seasonal exceptions so on. But they often do pick up on the > specific subtleties of the real world semantics e.g. expressing exceptions > to opening hours or times that cross midnight. The additional conceptual > burdens of dealing with the larger quirks in the schema.org design falls > more upon the much smaller community gathered here, where we are evolving > the vocabulary itself. > > Having said that, we ought to make sure that Anthony's (and others') > various observations of quirks and inconsistencies in naming/definition are > not lost in these mail archives. Anthony - could you file them, grouped in > whatever way makes sense, over in Github. This doesn't guarantee that all > your suggestions will get adopted but it provides a more topic-based way of > keeping track of the issues in a cross-reference-friendly format than we > get here in email. -> http://github.com/schemaorg/schemaorg/issues > > cheers, > > Dan > > Martin >> ----------------------------------- >> martin hepp http://www.heppnetz.de >> mhepp@computer.org @mfhepp >> >> >> >> >> > On 13 Jun 2018, at 23:09, Anthony Moretti <anthony.moretti@gmail.com> >> wrote: >> > >> > I took a closer look at the use of "Specification" and I now see that >> it's only used to mean "Type" in one place in the schema - >> PropertyValueSpecification, the other eight times it's used to refer to a >> StructuredValue, so the generalization I made in my last message was wrong, >> I'm sorry. >> > >> > I tried to see where naming conventions might create more naming >> consistency and I'm wondering what people think about these ideas? >> > • For StructuredValue types: "Specification", or alternatively >> "Description", should either be removed or added to all. (My own preference >> is added.) >> > • For Enumeration types: "Type" should either be removed or added >> to all. (My own preference is removed.) >> > I then looked for more cases where appending "Type" to names of >> types-of-types might create consistency: >> > >> > CourseType (currently Course) >> > Course (currently CourseInstance) >> > >> > ProductType (currently ProductModel, subtype of Product) >> > Product >> > IndividualProduct (suggest removing) >> > >> > PropertyValueType (currently PropertyValueSpecification) >> > PropertyValue >> > >> > AudienceType (currently Audience) >> > DishOrDrinkType (currently MenuItem) >> > QuantityType (currently Quantity) >> > RoomType (currently BedDetails) >> > >> > I think I now understand the opposition to making Offer etc. a subtype >> of Event. So my only proposals regarding Event/Intangible are: >> > >> > Event >> > DeliveryEvent >> > ParcelDeliveryEvent (currently ParcelDelivery, subtype of >> Intangible) >> > Trip (currently subtype of Intangible) >> > >> > Any feedback on these ideas would be awesome! >> > >> > Anthony >> > >> > On Tue, Jun 12, 2018 at 12:17 PM Anthony Moretti < >> anthony.moretti@gmail.com> wrote: >> > I admit I didn't see CourseInstance under Event. I still have an issue >> with the naming though because as it stands we have "instances of Courses" >> and "instances of CourseInstances": >> > >> > Course >> > Stanford CS101 (Course instance) >> > >> > Event >> > CourseInstance >> > StanfordCS101 >> > Stanford CS101 2018-19 (CourseInstance instance) >> > >> > It comes down to how to name things when types are also desirable as >> instances. A couple of strategies already in use in Schema are to append >> "Specification" or "Model" to the type name. So this might work for courses: >> > >> > CourseSpecification >> > Stanford CS101 >> > >> > Event >> > Course >> > StanfordCS101 >> > Stanford CS101 2018-19 >> > >> > The same could be done for Offer: >> > >> > OfferSpecification >> > Macy's 50% Black Friday sale >> > >> > Event >> > Offer >> > Macy's 50% Black Friday sale 2018 >> > >> > Likewise, ProductModel ideally shouldn't be a subtype of Product (I >> think the reasoning about reuse of properties such as "weight" is flawed). >> It'd make more sense to follow the same pattern as the previous examples: >> > >> > ProductModel >> > iPhone X >> > >> > Product >> > iPhone X (serial number 12345678) >> > >> > And IndividualProduct would be removed entirely because of redundancy >> with Product. I think that when looking at type names, inclusion of >> "Individual", "Instance", or "Occurrence" are signs of potential naming or >> structural issues. >> > >> > In my view we could possibly also have a consistent and simple naming >> convention by using "Type", instead of "Specification" or "Model" for >> example, in all places where types are instances, so: >> > >> > CourseType >> > OfferType >> > ProductType >> > >> > (It even scales in the rare situations you need to model types of types >> and so on: TypeType, TypeTypeType...) >> > >> > On the separate topic of Events, Peter and Simon brought up endurants >> and perdurants - what about schema:Event is insufficient to cover all >> perdurants? I'm not saying we should add all types of perdurants to Event, >> that's not the intention of Schema, but why can't types we already have, >> like Trip, be moved from Intangible and put under Event? Why is a Festival >> an Event but a Trip not? >> > >> > Anthony >> > >> > On Tue, Jun 12, 2018 at 8:43 AM Sebastian Samaruga <ssamarug@gmail.com> >> wrote: >> > I've just uploaded PDF versions of the files so you can preview them in >> browser instead of downloading them. Thanks! >> > >> > On Mon, Jun 11, 2018, 9:32 PM <Simon.Cox@csiro.au> wrote: >> > Hey Sebastian – >> > >> > >> > >> > If you are using GitHub for blogging, then I suggest you write in >> Markdown, rather than attaching .docx. >> > >> > That way we can read your musings directly instead of having to >> download. >> > >> > >> > >> > From: Sebastian Samaruga [mailto:ssamarug@gmail.com] >> > Sent: Tuesday, 12 June, 2018 10:22 >> > To: Cox, Simon (L&W, Clayton) <Simon.Cox@csiro.au> >> > Cc: Anthony Moretti <anthony.moretti@gmail.com>; Dan Brickley < >> danbri@google.com>; Peter F. Patel-Schneider <pfpschneider@gmail.com>; >> Richard Wallis <richard.wallis@dataliberate.com>; public-schemaorg@w3.org; >> W3C Semantic Web IG <semantic-web@w3.org>; public-rww <public-rww@w3.org> >> > Subject: Re: Schema.org and OWL >> > >> > >> > >> > I don't know if this really deserves attention in this context. I can't >> stop trying to figure out how to solve issues as such in this thread but >> also a more general way of using RDF (Quads) to solve other kind of >> mediation / alignment issues in a distributed manner. >> > >> > >> > >> > As I go along I'm dumping my thoughts in an ideas scrapbook manner. As >> long as I'll be able to put them into readable documents format I'll be >> publishing them in raw form, just for the case I'm missing something. >> > >> > >> > >> > https://github.com/ssamarug/ssamarug >> > >> > >> > >> > http://exampledotorg.blogspot.com >> > >> > >> > >> > (warning: these are just raw statements of concepts or ideas. I don't >> currently have time to put them in an orderly fashion, the purpose is >> solely to have them somewhere in the hope of having a chance to collaborate >> into developing them further). >> > >> > >> > >> > Best, >> > >> > Sebastian. >> > >> > >> > >> > >> > >> > On Mon, Jun 11, 2018, 1:30 PM Sebastian Samaruga <ssamarug@gmail.com> >> wrote: >> > >> > In the realm of upper ontologies I think ISO-15926 [1] handles this >> sort of issues nicely (that's why I'm copying this thread to semantic-web) >> but it is a whole of an upper ontology and didn't have the time to >> understand it completely. >> > >> > >> > >> > For what is whorth for me, I'm trying to adapt an object-oriented >> design pattern (DCI: Data, Context and Interactions [2]) to the realm of >> RDF Quads metamodels. There I regard of dimensionally aggregated data (D) >> for which schema occurrences (C) play roles in behaviors instances / flows >> (I). >> > >> > >> > >> > I'm working in a formal description of the later, and I've also posted >> previously some blurry early drafts. I also have a strong focus in ontology >> alignments / translations so the use case could fit for generating other >> schema documents. Regards, >> > >> > Sebastián. >> > >> > >> > >> > [1] https://en.m.wikipedia.org/wiki/ISO_15926 >> > >> > >> > >> > [2] https://en.m.wikipedia.org/wiki/Data,_context_and_interaction >> > >> > >> > >> > >> > >> > On Mon, Jun 11, 2018, 5:23 AM <Simon.Cox@csiro.au> wrote: >> > >> > My read of all this is that >> > >> > >> > >> > schema.org:Event subClassOf natural-language:Event . >> > >> > >> > >> > You need to recognize that the name of the concept in schema.org is >> more specialized that the use of the word 'Event' in all English-language >> usages. >> > >> > >> > >> > The upper-ontologies resolve this by using a more technical word - like >> occurrent or perdurant - which includes all time-bounded things including >> both planned events, unplanned incidents, things that move around, as well >> as other kinds of interactions. But even these attempts to define >> universals must be taken with a pinch of salt. Classification is contextual >> - the 'same thing' may be classified differently in different applications. >> The main application of schema.org is SEO, so the classification system >> is tuned to that. >> > >> > >> > >> > >> > >> > Simon J D Cox >> > Research Scientist >> > Land and Water >> > CSIRO >> > >> > E simon.cox@csiro.au T +61 3 9545 2365 M +61 403 302 672 >> > Physical: Reception Central, Bayview Avenue, Clayton, Vic 3168 >> > Deliveries: Gate 3, Normanby Road, Clayton, Vic 3168 >> > Postal: Private Bag 10, Clayton South, Vic 3169 >> > people.csiro.au/C/S/Simon-Cox >> > orcid.org/0000-0002-3884-3420 >> > researchgate.net/profile/Simon_Cox3 >> > >> > From: Anthony Moretti <anthony.moretti@gmail.com> >> > Sent: Monday, 11 June 2018 8:26 AM >> > To: Dan Brickley >> > Cc: Peter F. Patel-Schneider; Richard Wallis; public-schemaorg@w3.org >> > Subject: Re: Schema.org and OWL >> > >> > >> > >> > Yep I definitely understand it doesn't imply disjointedness. But >> subclassing is answered by the "some or all" test, and I'd argue that all >> instances of these types are events. For example, is there an example of a >> trip that is not an event? >> > >> > And yep I completely agree, some not all books have current offers for >> sale/trade, so books are not a subtype of product. And I completely agree >> with the second example too, some not all things being offered are creative >> works. For example, an orange being offered for sale is a product but not a >> creative work, thus not all products are creative works. So I don't think >> those are examples of tradeoffs by schema.org, they're completely >> correct modeling by schema.org. >> > >> > If things like trips aren't considered events then strange behavior or >> additional work for people will result. For example a reasoner might look >> for all events to display on a calendar, but with the current structure all >> trips will have to be additionally typed as events, when in my view it >> should be implicit from already being classified as a trip. >> > >> > >> > On Sun, Jun 10, 2018 at 2:38 PM Dan Brickley <danbri@google.com> wrote: >> > >> > The lack of a "subclassof" relationship doesn't mean we consider the >> types disjoint. You might similarly argue that all books are products, or >> that all products are creative works. While we respect the efforts of the >> ontologies community, Schema org is a bit different in the tradeoffs we >> have chosen to make. The looseness may be frustrating but it has also >> helped us grow this thing incrementally. >> > >> > >> > >> > Dan >> > >> > >> > >> > On Sun, 10 Jun 2018, 14:28 Anthony Moretti, <anthony.moretti@gmail.com> >> wrote: >> > >> > If we believe schema.org will be used long into the future then even >> if changes are hard we should try to make them right? >> > >> > Arguing by word origins, even the word "action" comes from "event". >> Using the dictionary on Google: >> > >> > "action" >> > "act" >> > "actus" (Latin) - event, thing done >> > >> > Arguing by structure, Actions on schema.org duplicate the startDate >> and endDate properties (startTime and endTime). Additionally, Actions have >> a state property on schema.org but Events do not, yet all action states >> can all be derived from more general event states. So putting Action, or >> any type with a startDate or endDate, as a subtype of Event actually >> removes redundancy. >> > >> > A simple test to determine whether something is an event or not is can >> it be put on a calendar and look normal? I think instances of all the types >> I mentioned can: >> > >> > Event >> > Action >> > Course >> > Offer >> > ParcelDelivery >> > Relationship >> > Trip >> > >> > Anthony >> > >> > >> > On Sun, Jun 10, 2018 at 11:38 AM Dan Brickley <danbri@google.com> >> wrote: >> > >> > Yeah, we decided against cramming Actions under Event a long time ago, >> even if it has a certain appeal; I' d say same goes for the other event-ish >> types. >> > >> > >> > >> > On Sun, 10 Jun 2018, 11:24 Peter F. Patel-Schneider, < >> pfpschneider@gmail.com> wrote: >> > >> > It's very difficult to determine what things are instance of schema.org >> Event >> > because the guidance is so slim, particularly as we are not supposed >> to take >> > into account most of the information on http://schema.org/Event. My >> view is >> > that even if we are supposed to ignore everything after "certain time >> and >> > location", then schema.org Event should be read narrowly, excluding >> things >> > that don't have a certain time or don't have a certain location. This >> would >> > rule out Action, ParcelDelivery (as the entire delivery process), and >> Trip, as >> > these generally take place over several locations. Offer is ruled out >> > because it often doesn't have a location at all and its temporal >> information >> > doesn't have to do with its "happening". Course is also ruled out >> because it >> > is more than a sequence of lectures. >> > >> > >> > One could take an expansive view of schema.org Event, perhaps saying >> that its >> > instances are anything that has a temporal component and a spatial >> > component. So Bill Murray is an instance of schema.org Event via his >> birth >> > date and his location on Earth, as is his membership in the cast of >> > Ghostbusters. But then what things aren't instances of Event (besides >> > platonic entities like 3, if you assume that there are any truly >> platonic >> > entities)? >> > >> > >> > Is there a middle ground? Formal ontologists have attempted to create >> > one---dividing the universe into endurants and perdurants. But I don't >> see >> > that schema.org Event is getting at the meaning of perdurant. >> > >> > >> > peter >> > >> > >> > >> > >> > On 06/10/2018 12:32 AM, Anthony Moretti wrote: >> > > Let's get the easy ones out of the way before looking at Roles. The >> > > following are obviously subtypes of event, I might create an issue on >> GitHub >> > > to get more feedback: >> > > >> > > Event >> > > >> > > Action >> > > >> > > Course >> > > >> > > Offer >> > > >> > > ParcelDelivery >> > > >> > > Trip >> > > >> > > >> > > I'll argue for Role now. In my view, it would be easier to understand >> if the >> > > terminology was Relation, or Relationship, rather than Role. >> > > >> > > An event is either: >> > > >> > > * A period of time (e.g. Jun 9, 2018, 12 PM - 1 PM) >> > > * The period of time that a statement, explicit or implicit, is >> true (e.g. >> > > My run this morning = Anthony isRunning True) >> > > >> > > To be clear, having the same statement exist with different periods of >> > > validity can still be consistent: >> > > >> > > * Anthony isRunning True (Jun 9, 2018, 12 PM - 1 PM) >> > > * Anthony isRunning True (Jun 8, 2018, 12 PM - 1 PM) >> > > >> > > If you look at temporal databases >> > > <https://en.wikipedia.org/wiki/Temporal_database> every fact has a >> valid >> > > time <https://en.wikipedia.org/wiki/Valid_time> - the time period >> during >> > > which the fact is true. Therefore if you reify any fact or >> relationship you >> > > produce something with start or end times, therefore producing an >> event. >> > > >> > > In schema.org <http://schema.org>: >> > > >> > > 1. All Roles are reified relationships. >> > > 2. Therefore all Roles have "valid times". >> > > 3. Therefore all Roles have start or end times. >> > > 4. Therefore all Roles are events. >> > > >> > > If the terminology was updated it would look like: >> > > >> > > Event >> > > >> > > Relationship, or Relation (currently Role) >> > > >> > > >> > > Regarding Bill Murray, what is being modeled if not the fact that Bill >> > > Murray was involved as an actor during its filming, and so for a >> period of time? >> > > >> > > And yep, I agree that you can define an entity and separately define >> an >> > > event that represents its period of existence. But you can't do that >> for an >> > > event, and in like fashion you can't do that for a statement either, >> it just >> > > wouldn't make sense for either right? >> > > >> > > Anthony >> > > >> > > >> > > On Sat, Jun 9, 2018 at 6:52 PM Peter F. Patel-Schneider >> > > <pfpschneider@gmail.com <mailto:pfpschneider@gmail.com>> wrote: >> > > >> > > Yes, many Roles in schema.org <http://schema.org> are events, >> and could >> > > be so modelled. But not >> > > all, in my opinion, or at least not usefully. >> > > >> > > >> > > For example the relationship between Bill Murray and Ghostbusters >> is not an >> > > event. It was, perhaps, initiated by a bunch of events, namely a >> > > sequence of >> > > acting performances that were captured and edited together to >> form the >> > > movie. >> > > However, that bunch of events is not the relationship being >> modelled. >> > > >> > > >> > > It's just like one might model people as their lives, i.e., an >> event that >> > > plays out (roughly) from conception to death. But I find it >> useful to >> > > distinguish between a person and their life event. >> > > >> > > >> > > peter >> > > >> > > >> > > >> > > On 06/06/2018 09:01 PM, Anthony Moretti wrote: >> > > > I agree that the first problem to do with strings can be solved >> by boxing >> > > > them into anonymous individuals. On the second problem to do >> with Roles I >> > > > agree that you can't do a simple "subjectOf" transform because >> Role is not >> > > > in the domain of "about", but maybe defining a new property >> such as >> > > > "participantIn" (domain Thing, range Role) and using it >> wherever a Role is >> > > > the object of a statement might keep about the same level of >> meaning (not >> > > > very good) but at least make it consistent OWL? So your example >> would be >> > > > transformed to: >> > > > >> > > > DJT : Person >> > > > >> > > > participantIn ? : Role >> > > > >> > > > spouse MM : Person >> > > > >> > > > startDate : 1993 >> > > > >> > > > endDate : 1999 >> > > > >> > > > participantIn ? : Role >> > > > >> > > > spouse IT : Person >> > > > >> > > > startDate : 1977 >> > > > >> > > > endDate : 1992 >> > > > >> > > > >> > > > A more general solution using guidance >> > > > from https://www.w3.org/TR/swbp-n-aryRelations/ and with >> better meaning >> > > > might be: >> > > > >> > > > DJT : Person >> > > > >> > > > isSpouseFor ? : MarriageRelation >> > > > >> > > > spouse DJT : Person >> > > > >> > > > spouse MM : Person >> > > > >> > > > startDate : 1993 >> > > > >> > > > endDate : 1999 >> > > > >> > > > isSpouseFor ? : MarriageRelation >> > > > >> > > > spouse DJT : Person >> > > > >> > > > spouse IT : Person >> > > > >> > > > startDate : 1977 >> > > > >> > > > endDate : 1992 >> > > > >> > > > >> > > > Your question about movie roles is also solved by this, for >> example: >> > > > >> > > > Bill Murray : Person >> > > > >> > > > isActorFor ? : PerformanceRelation >> > > > >> > > > actor Bill Murray : Person >> > > > >> > > > movie Ghostbusters : Movie >> > > > >> > > > characterName : Dr. Peter Venkman >> > > > >> > > > startDate : 1983 >> > > > >> > > > endDate : 1984 >> > > > >> > > > >> > > > Class hierarchy: >> > > > >> > > > Event >> > > > >> > > > Relation >> > > > >> > > > MarriageRelation >> > > > >> > > > PerformanceRelation >> > > > >> > > > >> > > > I think confusion might come from the many English meanings of >> "role": >> > > > >> > > > Type of role, e.g. Quarterback - no start or end dates. >> > > > Instance of a role, e.g. 49ers quarterback 1979-1992 - >> potential start >> > > > and end dates. >> > > > Character, e.g. Hamlet - no start or end dates. >> > > > >> > > > >> > > > So I'm still lead to believe that Role/Relation and several >> other types in >> > > > schema.org <http://schema.org> <http://schema.org> are >> subtypes of >> > > Event because their instances >> > > > always have potential start and end dates: >> > > > >> > > > Event >> > > > >> > > > Action >> > > > >> > > > Course >> > > > >> > > > Role/Relation >> > > > >> > > > Offer >> > > > >> > > > ParcelDelivery >> > > > >> > > > Trip >> > > > >> > > > >> > > > Anybody else think this too? I'm a bit new to this so hope I'm >> not putting >> > > > something too strange out there! >> > > > >> > > > Anthony >> > > > >> > > > >> > > > On Wed, Jun 6, 2018 at 3:20 PM Peter F. Patel-Schneider >> > > > <pfpschneider@gmail.com <mailto:pfpschneider@gmail.com> >> > > <mailto:pfpschneider@gmail.com <mailto:pfpschneider@gmail.com>>> >> wrote: >> > > > >> > > > The short-circuiting of Role in schema.org < >> http://schema.org> >> > > <http://schema.org> is >> > > > certainly outside of >> > > > schema.org <http://schema.org> <http://schema.org>. OWL >> has >> > > nothing that can do the right >> > > > thing with the following >> > > > schema.org <http://schema.org> <http://schema.org> data >> > > > >> > > > DJT : Person >> > > > spouse ? : Role >> > > > spouse MM : Person >> > > > startDate : 1991 >> > > > endDate : 1999 >> > > > spouse ? : Role >> > > > spouse IT : Person >> > > > startDate : 1977 >> > > > endDate: 1992 >> > > > spouse MT : Person >> > > > particularly in conjunction with >> > > > spouse >> > > > domain Person >> > > > range Person >> > > > >> > > > Except that you could turn *all* property values (except >> maybe for >> > > those >> > > > properties that are guaranteed never to have a Role >> intermediary) into >> > > > events >> > > > *before* they got to OWL. This would look something like: >> > > > >> > > > DJT : Person >> > > > spouseEvent ? : SpouseEvent >> > > > spouse MM : Person >> > > > startDate : 1991 >> > > > endDate : 1999 >> > > > spouseEvent ? : SpouseEvent >> > > > spouse IT : Person >> > > > startDate : 1997 >> > > > endDate : 1992 >> > > > spouseEvent ? : SpouseEvent >> > > > spouse MT : Person >> > > > spouse range Person >> > > > domain SpouseEvent >> > > > spouseEvent range SpouseEvent >> > > > domain Person >> > > > SpouseEvent sub Event >> > > > startDate range Date >> > > > endDate range Date >> > > > >> > > > Hah! That turned out better than I thought it would, but I >> view the >> > > > need for >> > > > the transform as showing that schema.org <http://schema.org >> > >> > > <http://schema.org> Role is >> > > > outside the purview of OWL >> > > > because it requires major surgery to the underlying >> ontology (as >> > > opposed >> > > > to a >> > > > transform to handle "strings as things" that just replaces >> such >> > > strings >> > > > with a >> > > > blank node connected to the string by some sort of >> description >> > > property >> > > > which >> > > > doesn't require such surgery). >> > > > >> > > > And then what do you do about movie roles? They shouldn't >> have start >> > > > and end >> > > > dates, or even have the possibility of start and end dates. >> > > > >> > > > peter >> > > > >> > > > >> > > > >> > > > On 06/06/2018 02:50 PM, Anthony Moretti wrote: >> > > > > Peter, when you say "roles fall outside the purview of >> OWL" is >> > > it possible >> > > > > that Role should be a subtype of Event, thus requiring no >> special >> > > > treatment? >> > > > > I say that because individual roles have potential start >> and end >> > > dates. >> > > > > >> > > > > If you continue that thinking you end up with several >> types that >> > > might be >> > > > > considered subtypes of Event: >> > > > > >> > > > > Event >> > > > > >> > > > > Action >> > > > > Course >> > > > > Role >> > > > > Offer >> > > > > Parcel delivery >> > > > > Trip >> > > > > >> > > > > >> > > > > Anthony >> > > > > >> > > > > On Wed, Jun 6, 2018 at 7:42 AM Peter F. Patel-Schneider >> > > > > <pfpschneider@gmail.com <mailto:pfpschneider@gmail.com> >> > > <mailto:pfpschneider@gmail.com <mailto:pfpschneider@gmail.com>> >> > > > <mailto:pfpschneider@gmail.com <mailto: >> pfpschneider@gmail.com> >> > > <mailto:pfpschneider@gmail.com <mailto:pfpschneider@gmail.com>>>> >> wrote: >> > > > > >> > > > > OK, it appears that you are trying to produce an OWL >> > > ontology that >> > > > would >> > > > > accept schema.org <http://schema.org> < >> http://schema.org> >> > > <http://schema.org> >> > > > documents that would accept >> > > > > unexceptional schema.org <http://schema.org> >> > > <http://schema.org> <http://schema.org> >> > > > > documents (under some loose definition of what makes >> an >> > > unexceptional >> > > > > schema.org <http://schema.org> <http://schema.org> >> > > <http://schema.org> document). >> > > > > >> > > > > >> > > > > But you are running up against problems with "strings >> as >> > > things" and >> > > > > Roles. >> > > > > >> > > > > >> > > > > Look at about and subjectOf. Any use of a string as >> a >> > > value for >> > > > about is >> > > > > going to make that string an instance of two OWL >> Classes >> > > (the range of >> > > > > about, >> > > > > which includes Text, and the domain of subjectOf, >> which >> > > doesn't). >> > > > This >> > > > > is not >> > > > > permissible in OWL. >> > > > > >> > > > > >> > > > > Using a role as a value for subjectOf will make the >> role node an >> > > > instance of >> > > > > the domain of about, which doesn't include Role. >> Roles fall >> > > > outside the >> > > > > purview of OWL. >> > > > > >> > > > > >> > > > > What I think has to be done for "strings as things" >> is to >> > > > preprocess them as >> > > > > an anonymous node with the string as the value of some >> > > description >> > > > > property. >> > > > > Roles need to be short-circuited and the role values >> > > eliminated. >> > > > If the >> > > > > role >> > > > > values are to be retained then some sort of fancy >> > > reification has >> > > > to be >> > > > > introduced. >> > > > > >> > > > > >> > > > > But a lot of this is guesswork, as it is unclear just >> what >> > > "strings as >> > > > > things" >> > > > > and Roles mean in schema.org <http://schema.org> >> > > <http://schema.org> >> > > > <http://schema.org>. (I haven't looked >> > > > > closely at the use of URLs >> > > > > as stand-ins for objects but my guess is that that is >> similar to >> > > > "strings as >> > > > > things".) >> > > > > >> > > > > >> > > > > >> > > > > OWL makes a distinction between object and data >> values, and this >> > > > distinction >> > > > > has to be carried through to the ontology, where >> there are >> > > classes and >> > > > > datatypes. As far as I can tell Text should be a >> datatype. >> > > > > >> > > > > >> > > > > >> > > > > >> > > > > peter >> > > > > >> > > > > >> > > > > >> > > > > On 06/06/2018 07:09 AM, Richard Wallis wrote: >> > > > > > Just the fresh pair of experienced eyes I needed! - >> Thanks >> > > @Thomas >> > > > > > >> > > > > > @Danbri - not “wasting a lot of time agonising", in >> simple >> > > terms >> > > > I’m just >> > > > > > [selfishly] trying to get a useful version to load >> > > into Protégé and >> > > > > > hopefully helping a few others at the same time. >> > > > > > >> > > > > > @Peter thanks for your thoughtful questions. As >> you can see >> > > > from the >> > > > > above >> > > > > > the prime simple objective is to get it visible >> > > in Protégé. Beyond >> > > > > that, it >> > > > > > is to capture the class and property hierarchy of >> Schema.org >> > > > including >> > > > > > the multiple domain/ranges of properties defined [In >> > > Schema.org] >> > > > using >> > > > > > domainIncludes & rangeIncludes, in a way that a tool >> > > > like Protégé can cope >> > > > > > with. As for ranges, it includes the assumption >> that >> > > properties, in >> > > > > > addition to the defined range(s), also have Text, >> URL, and >> > > Role >> > > > > included in >> > > > > > their range. >> > > > > > >> > > > > > Once I’ve done it, I want to add the simple >> generating code to >> > > > the Schema >> > > > > > scripts run at release time so that it can be kept >> up to date. >> > > > > > >> > > > > > >> > > > > > ~Richard. >> > > > > > >> > > > > > Richard Wallis >> > > > > > Founder, Data Liberate >> > > > > > http://dataliberate.com >> > > > > > Linkedin: http://www.linkedin.com/in/richardwallis >> > > > > > Twitter: @rjw >> > > > > > >> > > > > > On 6 June 2018 at 14:45, Peter F. Patel-Schneider >> > > > > <pfpschneider@gmail.com <mailto: >> pfpschneider@gmail.com> >> > > <mailto:pfpschneider@gmail.com <mailto:pfpschneider@gmail.com>> >> > > > <mailto:pfpschneider@gmail.com <mailto: >> pfpschneider@gmail.com> >> > > <mailto:pfpschneider@gmail.com <mailto:pfpschneider@gmail.com>>> >> > > > > > <mailto:pfpschneider@gmail.com >> > > <mailto:pfpschneider@gmail.com> <mailto:pfpschneider@gmail.com >> > > <mailto:pfpschneider@gmail.com>> >> > > > <mailto:pfpschneider@gmail.com <mailto: >> pfpschneider@gmail.com> >> > > <mailto:pfpschneider@gmail.com <mailto:pfpschneider@gmail.com>>>>> >> wrote: >> > > > > > >> > > > > > It's hard to say much about the file without >> knowing >> > > what it is >> > > > > supposed to >> > > > > > capture. >> > > > > > >> > > > > > >> > > > > > It is supposed to capture the class and property >> > > hierarchy and >> > > > > property >> > > > > > restrictions or schema.org <http://schema.org> >> > > <http://schema.org> >> > > > <http://schema.org> >> > > > > <http://schema.org>, but not necessarily in a >> > > > > > form compatible with RDFS >> > > > > > or OWL? >> > > > > > >> > > > > > >> > > > > > Is it supposed to faithfully encode the model >> theory of >> > > > schema.org <http://schema.org> <http://schema.org> >> > > > > <http://schema.org> >> > > > > > <http://schema.org> in OWL? >> > > > > > If so, where is the document for this theory? >> > > > > > >> > > > > > >> > > > > > Is it supposed to capture "strings as things" >> or Roles? >> > > > > > >> > > > > > >> > > > > > How does it view property domains and ranges? >> As >> > > axioms? >> > > > As strict >> > > > > > constraints? As soft constraints? >> > > > > > >> > > > > > >> > > > > > I would also move from rdf/xml to turtle, which >> is >> > > easier to >> > > > write and >> > > > > > easier >> > > > > > to read. >> > > > > > >> > > > > > >> > > > > > peter >> > > > > > >> > > > > > >> > > > > > >> > > > > > On 06/06/2018 05:05 AM, Richard Wallis wrote: >> > > > > > > Calling folks with more OWL experience than >> me! >> > > > > > > >> > > > > > > The schema.org <http://schema.org> >> > > <http://schema.org> <http://schema.org> >> > > > <http://schema.org> >> > > > > <http://schema.org> site has an OWL >> > > > > > definition file that has >> > > > > > > not been maintained since April >> > > > > 2014: http://schema.org/docs/schemaorg.owl >> > > > > <http://schema.org/docs/schemaorg.owl>. >> > > > > > > Also the structure and syntax of the file >> needs some >> > > > attention. >> > > > > > > >> > > > > > > To help with the occasional questions about >> accessing >> > > > processable >> > > > > > > representations of the vocabulary; to attempt >> to >> > > close an >> > > > issue >> > > > > (#1611 >> > > > > > > < >> https://github.com/schemaorg/schemaorg/issues/1611 >> > > > > > >> > > <https://github.com/schemaorg/schemaorg/issues/1611>>); and to >> > > > > help with a >> > > > > > > personal project, I have had a look at >> producing an >> > > up to >> > > > date, >> > > > > improved, >> > > > > > > maintainable version of the file. >> > > > > > > >> > > > > > > My first attempt can be downloaded/viewed >> > > > > > > >> > > > here: >> https://s3.amazonaws.com/rjwPublicData/public/schemaorg.owl >> > > > > > >> > > <https://s3.amazonaws.com/rjwPublicData/public/schemaorg.owl> >> > > > > > > >> > > > > > > I am looking for comments, suggestions, and >> help >> > > around a few >> > > > > aspects of >> > > > > > > this work in progress: >> > > > > > > >> > > > > > > * Is it generally ‘a good owl file’ >> > > > > > > >> > > > > > > * Should it contain more/less info about >> > > the vocabulary and >> > > > > its terms >> > > > > > > >> > > > > > > * Specifically with reference to >> domainIncludes and >> > > > rangeInclude - >> > > > > > mapped >> > > > > > > to rdfs:domain & rdfs:range with >> > > owl:unionOfcollections: >> > > > > > > >> > > > > > > o Is this the best/only way to >> represent multiple >> > > > domain & >> > > > > > ranges for >> > > > > > > an objectproperty? >> > > > > > > >> > > > > > > o Have I got the syntax correct? >> > > > > > > >> > > > > > > * Several people use Protégé >> > > > <https://protege.stanford.edu/> as a >> > > > > > tool for >> > > > > > > this kind of effort - I am trying to >> identify >> > > what syntax, >> > > > > will enable >> > > > > > > this tool to recognise the multiple >> > > domain/ranges when >> > > > importing >> > > > > > this file. >> > > > > > > >> > > > > > > If anyone out there with more OWL experience >> than me >> > > (not >> > > > > difficult), >> > > > > > could >> > > > > > > spend a few minutes taking a look at this and >> > > commenting, it >> > > > > would be >> > > > > > > greatly appreciated. >> > > > > > > >> > > > > > > ~Richard >> > > > > > > >> > > > > > > Richard Wallis >> > > > > > > Founder, Data Liberate >> > > > > > > http://dataliberate.com >> > > > > > > Linkedin: >> http://www.linkedin.com/in/richardwallis >> > > > > > <http://www.linkedin.com/in/richardwallis> >> > > > > > > Twitter: @rjw >> > > > > > >> > > > > > >> > > > > > >> > > > > >> > > > > >> > > > >> > > >> > >> > >> >>
Received on Thursday, 14 June 2018 03:25:19 UTC