- From: Thad Guidry <thadguidry@gmail.com>
- Date: Sun, 3 Aug 2014 09:13:17 -0500
- To: Jarno van Driel <jarnovandriel@gmail.com>
- Cc: Gregg Kellogg <gregg@greggkellogg.net>, Dan Brickley <danbri@google.com>, "martin.hepp@ebusiness-unibw.org" <martin.hepp@ebusiness-unibw.org>, "Wallis,Richard" <Richard.Wallis@oclc.org>, W3C Web Schemas Task Force <public-vocabs@w3.org>, "Jason Johnson (BING)" <jasjoh@microsoft.com>, Juraj Kabát <kabat.juraj@gmail.com>
- Message-ID: <CAChbWaODGHH+c9bmC9PezmwBB5ELYan7ibwk=v1DTVSgN+J8qQ@mail.gmail.com>
Jarno, Reverse properties in a directed graph are what Freebase sets up. (or can with schema) http://en.wikipedia.org/wiki/Directed_graph A relationship between 2 entities (in a graph called vertices or nodes). Both node A and node B, each have a relationship to describe. You can describe a 'reverse' relationship for any reciprocal node. A<->B B<->A Where node A needs to say "I am Luke Skywalker", and node B needs to say "I am his father", and node C needs to say "I created node B" and "I created node A" and I am "George Lucas". -creator "has created" and where the reverse is true...where node A says ... "yeap, node C is my creator !" -created "has creator" ;-) On Sun, Aug 3, 2014 at 8:56 AM, Thad Guidry <thadguidry@gmail.com> wrote: > It is for reverse relations, just as Freebase does. > > However...the proposal > https://www.w3.org/wiki/WebSchemas/InverseProperties is not worded > correctly in some areas... .it should use "has a", instead of "is a" or "is > the". Someone needs to go through the proposal in more depth and make > necessary corrections that assert the appropriate reverse relationships so > that they make sense. > > Example: > > The line > > <link itemprop-reverse="creator" href="http://www.freebase.com/m/0yq9mqd"> > > expresses that http://www.freebase.com/m/0yq9mqd is the schema:creator of > the person "William Shakespeare". > > > "Romeo and Juliet" did not create William Shakespeare. His Mum and Dad > did. > > > > > On Sun, Aug 3, 2014 at 6:45 AM, Jarno van Driel <jarnovandriel@gmail.com> > wrote: > >> mmmmm, could it be there's a misunderstanding on the working of >> itemprop-reverse (and something that needs to be explained better in the >> proposal)? >> >> The way I understood it is that: >> itemprop-reverse="memberOf" equals itemprop="member", or, >> itemprop-reverse="hasPart" equals itemprop="isPartOf". >> >> Meaning itemprop-reverse is meant to express the opposite value of a >> property but not to express a reverse relation. >> >> Dan Brickley, Martin Hepp and Thad Guidry, how do you see this? >> >> >> 2014-08-02 23:56 GMT+02:00 Gregg Kellogg <gregg@greggkellogg.net>: >> >> On Aug 1, 2014, at 7:50 AM, Dan Brickley <danbri@google.com> wrote: >>> >>> > On 1 August 2014 15:35, martin.hepp@ebusiness-unibw.org >>> > <martin.hepp@ebusiness-unibw.org> wrote: >>> >> Richard, Jarno: >>> >> >>> >> Note that the itemprop-reverse proposal does not imply that there >>> should be no inverse properties in schema.org. It is just that we >>> should be able to use properties in both directions without the need to >>> define two properties, one for each direction. Inverse properties in the >>> vocabulary can make sense in some cases (like in the ongoing thread). >>> >> >>> >> So we should be clear about the fact that advancing the >>> itemprop-reverse proposal does not stop you from having both isPartOf and >>> hasPart. We should define inverses formally in the vocabulary (e.g. by >>> adding a property http://schema.org/inverseOf to the meta-model of >>> schema.org). >>> > >>> > Indeed. Personally I'm pretty supportive of hasPart, although it is >>> > hard to know where to draw the line. We didn't do it in the last >>> > revision when the focus was more on WebSite and we generalized >>> > isPartOf as a side effect. Both isPartOf and >>> > http://schema.org/containedIn have the awkward characteristic that the >>> > point from 'inner' things to 'outer', even while markup structure >>> > generally starts with containers and has their parts 'inside' in >>> > markup terms. We're taking a good look at Periodical this week so will >>> > get back to you all on that asap. >>> > >>> > BTW >>> https://www.w3.org/wiki/WebSchemas/Periodicals,_Articles_and_Multi-volume_Works >>> > would benefit from "we think this is pretty much done" -style >>> > read-throughs from other folk here. I've bounced it off a few more >>> > contacts from the library/bibliographic world and it seems to about >>> > right.... >>> >>> I've updated my Microdata to RDF implementation [1] to support >>> @itemprop-reverse, and need to clarify the interaction with @itemprop. >>> Consider the following example: >>> >>> <div itemscope itemtype="http://schema.org/Organization"> >>> <span itemprop="name">Cryptography Users</span> >>> <div itemprop-reverse="memberOf" itemprop="member" >>> itemscope >>> itemtype="http://schema.org/OrganizationRole"> >>> <div itemprop-reverse="memberOf" itemprop="member" >>> itemscope >>> itemtype="http://schema.org/Person"> >>> <span itemprop="name">Alice</span> >>> </div> >>> <span itemprop="startDate">1977</span> >>> </div> >>> </div> >>> >>> This doubly-links a Role, using memberOf as the inverse of member. The >>> resulting Turtle, would be: >>> >>> @prefix schema: <http://schema.org/> . >>> @prefix md: <http://www.w3.org/ns/md#> . >>> <> md:item (_:a) . >>> _:a a schema:Organization; >>> schema:name "Cryptography Users"; >>> schema:member _:b . >>> _:b a schema:OrganizationRole; >>> schema:startDate "1977"; >>> schema:member _:c; >>> schema:memberOf _:a . >>> _:c a schema:Person; >>> schema:name "Alice"; >>> schema:memberOf _:b . >>> >>> However, it's not clear that Microdata would support having both >>> @itemprop and @itemprop-reverse on the same element. I updated the Wiki to >>> indicate no, but this needs to be clarified with WHATWG and this list. >>> >>> (I'm also considering just dropping the md:item list, as not being too >>> useful; feedback on this would be appreciated. >>> >>> You can use this live through my distiller [2] (although, not the linter >>> yet). >>> >>> Gregg >>> >>> [1] https://github.com/ruby-rdf/rdf-microdata >>> [2] http://rdf.greggkellogg.net/distiller >>> >>> > Dan >>> > >>> >> Martin >>> >> >>> >> >>> >> >>> >> >>> >> On 01 Aug 2014, at 15:56, Wallis,Richard <Richard.Wallis@oclc.org> >>> wrote: >>> >> >>> >>> Agree that pushing for reverse property capability in Microdata is a >>> good thing. >>> >>> >>> >>> However, I must harmonise with Jarno about hasPart [click, hasPart - >>> click, hasPart - click..] as proposed in several places including the >>> Periodicals, Articles, & Mult-Volume Works proposal. >>> >>> >>> >>> Describing something like a multi-volume work, for example it is >>> quite possible that the individual parts are defined elsewhere on the web, >>> without knowledge of the the multi-volume description >>> >>> >>> >>> >>> >>> ~Richard >>> >>> >>> >>> >>> >>> On 1 Aug 2014, at 09:59, Jarno van Driel <jarnovandriel@gmail.com> >>> wrote: >>> >>> >>> >>>> "as Jarno knows, for he was involved in the discussion ;-)" >>> >>>> hehe, it could well be I mentioned the existence of the proposal >>> here and there. >>> >>>> >>> >>>> "Anyway, I'll take it to the HTML folks and report back." >>> >>>> Great, that would help a lot! >>> >>>> >>> >>>> Although I have to say (running the risk I sound like a broken >>> record) that I still believe adding an 'hasPart' property would help a lot >>> as well. I see both the <link> pointing to an itemid and itemprop-reverse >>> attribute as more advanced methods for mapping relations and fear that >>> folks, who are not too familiar with either microdata, will overlook them. >>> Having 'hasPart' as well will provide an easy and straightforward solution >>> for a property I suspect will be use quite a lot. Especially if the >>> schema.org provides sufficient examples on how to use it for layout >>> entities like WebPage, WebSite, SiteNavigationElement, WebPageElement, etc. >>> >>>> >>> >>>> >>> >>>> 2014-08-01 9:10 GMT+02:00 Dan Brickley <danbri@google.com>: >>> >>>> On 1 August 2014 07:52, martin.hepp@ebusiness-unibw.org >>> >>>> <martin.hepp@ebusiness-unibw.org> wrote: >>> >>>>> There is a fully-fledged proposal to add inverse properties to >>> microdata: >>> >>>>> >>> >>>>> https://www.w3.org/wiki/WebSchemas/InverseProperties >>> >>>>> >>> >>>>> (as Jarno knows, for he was involved in the discussion ;-) >>> >>>> >>> >>>> And I well remember too. We had also already begun a discussion on >>> the >>> >>>> WHATWG list, so the issue is well established. >>> >>>> >>> >>>>> Maybe we can ask Dan to look into this matter again? It would >>> really help to have this feature. >>> >>>> >>> >>>> I think it is indeed time to revisit. I didn't want to push for >>> >>>> @itemprop-reverse until the Role work stabilised, but now that is >>> done >>> >>>> I believe it's time. That said, there is still sometimes >>> justification >>> >>>> for adding a reverse property, and the site software now supports >>> >>>> linking such pairs where they exist (e.g. see >>> >>>> http://schema.org/alumni). Anyway, I'll take it to the HTML folks >>> and >>> >>>> report back. >>> >>>> >>> >>>> Dan >>> >>>> >>> >>>>> Best wishes / Mit freundlichen Grüßen >>> >>>>> >>> >>>>> Martin Hepp >>> >>>>> >>> >>>>> >>> >>>>> On 01 Aug 2014, at 00:40, Jarno van Driel <jarnovandriel@gmail.com> >>> wrote: >>> >>>>> >>> >>>>>> "I notice you don’t have an itemprop attribute in your first >>> <div> element. Was that intentional?" >>> >>>>>> >>> >>>>>> That would only have been possible if 'hasPart' (which isn't part >>> of the specification) could have been used (or itemprop-reverse="isPartOf"). >>> >>>>>> >>> >>>>>> Because there is no inverse property of 'isPartOf', nor a reverse >>> mechanism for microdata, Juraj is bound to chain the entities together by >>> making use of <link itemprop="isPartOf" href="[itemid-value]">. >>> >>>>>> >>> >>>>>> A cumbersome method, that now can be applied where it first >>> couldn't. All be it but one that can be improved still. >>> >>>>>> >>> >>>>>> >>> >>>>>> 2014-07-31 17:52 GMT+02:00 Jason Johnson (BING) < >>> jasjoh@microsoft.com>: >>> >>>>>> I notice you don’t have an itemprop attribute in your first <div> >>> element. Was that intentional? >>> >>>>>> >>> >>>>>> >>> >>>>>> >>> >>>>>> From: Juraj Kabát [mailto:kabat.juraj@gmail.com] >>> >>>>>> Sent: Tuesday, July 29, 2014 8:08 AM >>> >>>>>> To: public-vocabs@w3.org >>> >>>>>> Cc: W3C Web Schemas Task Force >>> >>>>>> Subject: Re: schema.org update, v1.8: added WebSite type; >>> broadened isPartOf to relate CreativeWorks >>> >>>>>> >>> >>>>>> >>> >>>>>> >>> >>>>>> When Ill try to add isPartOf property to ItemList, Im getting >>> this warning: >>> >>>>>> >>> >>>>>> WARNING: isPartOf field not specified in >>> http://schema.org/ItemList >>> >>>>>> >>> >>>>>> Example snippet: >>> >>>>>> <body itemid="#WebPage" itemscope itemtype=" >>> http://schema.org/CollectionPage"> >>> >>>>>> <div class="products" itemscope itemtype=" >>> http://schema.org/ItemList"> >>> >>>>>> <meta content="Unordered" itemprop="itemListOrder"> >>> >>>>>> <link itemprop="isPartOf" href="#WebPage"> >>> >>>>>> >>> >>>>>> <div itemtype="http://schema.org/Product" itemscope >>> itemprop="itemListElement"> >>> >>>>>> <img src="[url]" itemprop="image"> >>> >>>>>> <a href="[url]" itemprop="url"><span >>> itemprop="name">[name]</span></a> >>> >>>>>> <span itemtype="http://schema.org/Offer" itemscope >>> itemprop="offers"> >>> >>>>>> <span itemprop="price">[price]</span> >>> >>>>>> </span> >>> >>>>>> </div> >>> >>>>>> >>> >>>>>> <div itemtype="http://schema.org/Product" itemscope >>> itemprop="itemListElement"> >>> >>>>>> <img src="[url]" itemprop="image"> >>> >>>>>> <a href="[url]" itemprop="url"><span >>> itemprop="name">[name]</span></a> >>> >>>>>> <span itemtype="http://schema.org/Offer" itemscope >>> itemprop="offers"> >>> >>>>>> <span itemprop="price">[price]</span> >>> >>>>>> </span> >>> >>>>>> </div> >>> >>>>>> >>> >>>>>> </div> >>> >>>>>> </body> >>> >>>>>> >>> >>>>>> >>> >>>>>> But when Ill add isPartOf property to each ItemListElement, >>> everything works like expected. >>> >>>>>> What am I missing here? ItemList extends CreativeWork as well... >>> >>>>>> >>> >>>>>> Why can't I chain whole ItemList to parent but instead of that I >>> have to repeat myself for every element in list? >>> >>>>>> >>> >>>>>> >>> >>>>>> >>> >>>>>> On Mon, Jul 28, 2014 at 10:20 PM, Jarno van Driel < >>> jarnovandriel@gmail.com> wrote: >>> >>>>>> >>> >>>>>> Personally I most of all like the addition of WebSite (and it's >>> creative example) as well as the reworked 'isPartOf' most and I've already >>> started to implementing them. :-) >>> >>>>>> >>> >>>>>> >>> >>>>>> >>> >>>>>> But I would have been an even happier camper if 'hasPart' would >>> have been introduced as well. And even though chaining WebSite > WebPage > >>> WebPageElements > CreativeWork now can be achieved, without abusing >>> 'mentions' for this, it unfortunately is quite cumbersome in microdata >>> because one has to use itemid quite a lot, eg: >>> >>>>>> >>> >>>>>> >>> >>>>>> >>> >>>>>> <body itemid="#WebPage" itemscope itemtype=" >>> http://schema.org/WebPage"> >>> >>>>>> >>> >>>>>> <nav itemid="#SiteNavigationElement" itemscope itemtype=" >>> http://schema.org/SiteNavigationElement"> >>> >>>>>> >>> >>>>>> <link itemprop="isPartOf" href="#WebPage"> >>> >>>>>> >>> >>>>>> <ul> >>> >>>>>> >>> >>>>>> <li itemscope itemtype="http://schema.org/WebPage" >>> itemid="#WebPage-1"> >>> >>>>>> >>> >>>>>> <link itemprop="isPartOf" href="#SiteNavigationElement"> >>> >>>>>> >>> >>>>>> <a itemprop="url" href="[some-page-url]"> >>> >>>>>> >>> >>>>>> <span itemprop="name">[some-page-name]</span> >>> >>>>>> >>> >>>>>> </a> >>> >>>>>> >>> >>>>>> <ul> >>> >>>>>> >>> >>>>>> <li itemscope itemtype="http://schema.org/WebPage"> >>> >>>>>> >>> >>>>>> <link itemprop="isPartOf" href="#WebPage-1" /> >>> >>>>>> >>> >>>>>> <a itemprop="url" href="[some-page-url]"> >>> >>>>>> >>> >>>>>> <span itemprop="name">[some-page-name]</span> >>> >>>>>> >>> >>>>>> </a> >>> >>>>>> >>> >>>>>> </li> >>> >>>>>> >>> >>>>>> <li itemscope itemtype="http://schema.org/WebPage"> >>> >>>>>> >>> >>>>>> <link itemprop="isPartOf" href="#WebPage-1" /> >>> >>>>>> >>> >>>>>> <a itemprop="url" href="[some-page-url]"> >>> >>>>>> >>> >>>>>> <span itemprop="name">[some-page-name]</span> >>> >>>>>> >>> >>>>>> </a> >>> >>>>>> >>> >>>>>> </li> >>> >>>>>> >>> >>>>>> </ul> >>> >>>>>> >>> >>>>>> </li> >>> >>>>>> >>> >>>>>> </ul> >>> >>>>>> >>> >>>>>> </nav> >>> >>>>>> >>> >>>>>> </body> >>> >>>>>> >>> >>>>>> >>> >>>>>> >>> >>>>>> I'm still quite pleased with the update is as though. >>> >>>>>> >>> >>>>>> >>> >>>>>> >>> >>>>>> >>> >>>>>> >>> >>>>>> >>> >>>>>> >>> >>>>>> >>> >>>>>> >>> >>>>>> 2014-07-28 17:43 GMT+02:00 Dan Brickley <danbri@google.com>: >>> >>>>>> >>> >>>>>> >>> >>>>>> >>> >>>>>> previous update (1.7), >>> >>>>>> >>> http://lists.w3.org/Archives/Public/public-vocabs/2014Jul/0012.html >>> >>>>>> >>> >>>>>> A small schema.org update just went live: >>> >>>>>> >>> >>>>>> 1. We add a new CreativeWork type, "WebSite" >>> >>>>>> >>> >>>>>> http://schema.org/WebSite >>> >>>>>> >>> >>>>>> "A WebSite is a set of related web pages and other items typically >>> >>>>>> served from a single web domain and accessible via URLs." >>> >>>>>> >>> >>>>>> The example shows the use of this with SearchAction. >>> >>>>>> >>> >>>>>> 2. We adopt the proposal made by the bibextend group and other >>> >>>>>> collaborators, to broaden isPartOf. It now relates any >>> CreativeWork to >>> >>>>>> any other CreativeWork >>> >>>>>> >>> >>>>>> http://schema.org/isPartOf >>> >>>>>> >>> >>>>>> see also >>> https://www.w3.org/wiki/WebSchemas/Periodicals,_Articles_and_Multi-volume_Works >>> >>>>>> >>> >>>>>> 3. Potential Actions documentation >>> >>>>>> >>> >>>>>> The previously PDF-only Potential Actions document is now on the >>> site in HTML: >>> >>>>>> >>> >>>>>> http://schema.org/docs/actions.html >>> >>>>>> >>> >>>>>> 4. Adopted some markup fixes from Stephane Corlosquet (thanks!) >>> >>>>>> >>> >>>>>> https://github.com/rvguha/schemaorg/pull/71 >>> >>>>>> >>> >>>>>> 5. Improved consistency of encoding / associatedMedia description >>> >>>>>> (thanks Dan Scott!) >>> >>>>>> >>> >>>>>> https://github.com/rvguha/schemaorg/pull/35 >>> >>>>>> >>> >>>>>> 6. Updated some out-of-date sections of the FAQ: it now mentions >>> >>>>>> Yandex appropriately, acknowledges that there's life beyond >>> Microdata >>> >>>>>> (i.e. RDFa, JSON-LD), and doesn't talk about "version 0.9 draft" >>> any >>> >>>>>> more. >>> >>>>>> >>> >>>>>> https://github.com/rvguha/schemaorg/pull/69 >>> >>>>>> >>> >>>>>> Thanks all :) >>> >>>>>> >>> >>>>>> Dan >>> >>>>>> >>> >>>>>> >>> >>>>>> >>> >>>>>> >>> >>>>>> >>> >>>>>> >>> >>>>> >>> >>>> >>> >>> >>> >> >>> > >>> >>> >> > > > -- > -Thad > +ThadGuidry <https://www.google.com/+ThadGuidry> > Thad on LinkedIn <http://www.linkedin.com/in/thadguidry/> > -- -Thad +ThadGuidry <https://www.google.com/+ThadGuidry> Thad on LinkedIn <http://www.linkedin.com/in/thadguidry/>
Received on Sunday, 3 August 2014 14:13:46 UTC