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Re: Some interesting things that show up when using a reasoner to classify schema.org

From: Martin Hepp <martin.hepp@unibw.de>
Date: Thu, 22 Jan 2015 08:47:36 +0100
Cc: Justin Boyan <jaboyan@google.com>, Simon Spero <sesuncedu@gmail.com>, W3C Web Schemas Task Force <public-vocabs@w3.org>, Dan Brickley <danbri@google.com>
Message-Id: <2EC65BBA-E7DB-4473-BE7B-16D6B3FE9521@unibw.de>
To: "Peter F. Patel-Schneider" <pfpschneider@gmail.com>
No, what we need are different forms of domain and range axioms:

- database-style domain and range constraints so that a validator can spot contradictions and
- guidance on popular types for domain or range so that developers find them.

The second are not constraints and not local ranges, because an advanced user may still choose to use a type that is covered by the formal domain or range type (complex or atomic). We want to be able to say that formally, the range is Thing or something generic, but we want to help developers find the most likely subtypes without asking them to understand the full type hierarchy.

Best

Martin

--------------------------------------------------------
martin hepp
e-business & web science research group
universitaet der bundeswehr muenchen

e-mail:  martin.hepp@unibw.de
phone:   +49-(0)89-6004-4217
fax:     +49-(0)89-6004-4620
www:     http://www.unibw.de/ebusiness/ (group)
         http://www.heppnetz.de/ (personal)
skype:   mfhepp 
twitter: mfhepp





On 21 Jan 2015, at 18:28, Peter F. Patel-Schneider <pfpschneider@gmail.com> wrote:

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> It seems to me that what is needed here is local ranges, e.g., the range of
> http://schema.org/itemListElement for numbered lists is a number.
> 
> peter
> 
> 
> On 01/21/2015 08:51 AM, Justin Boyan wrote:
>> I like Martin's idea. We have the same issue with
>> http://schema.org/itemListElement , which can point to an arbitrary 
>> Thing, but where it's important to call out the special type of ListItem
>> for numbered lists.
>> 
>> On Wed Jan 21 2015 at 11:48:02 AM Simon Spero <sesuncedu@gmail.com 
>> <mailto:sesuncedu@gmail.com>> wrote:
>> 
>> The issue is somewhat complicated, in that the range is due to a 
>> historical name collision.
>> 
>> The only things which can have a purpose that is a  MedicalDevicePurpose 
>> are Medical devices. The only values of purpose these devices can have
>> are medical devices-
>> 
>> (interArgIsa1-2 purpose MedicalDevice MedicalDevicePurpose)
>> 
>> Simon
>> 
>> On Jan 21, 2015 11:21 AM, "Martin Hepp" <martin.hepp@unibw.de 
>> <mailto:martin.hepp@unibw.de>> wrote:
>> 
>> Hi Dan, A hands-on solution would be to add two internal "annotation" 
>> properties "rangeHint" and "domainHint" that allow explicitly triggering
>> the display of certain schema.org <http://schema.org> types in the
>> documentation.
>> 
>> 
>> <div typeof="rdf:Property" resource="http://schema.org/purpose"> ... 
>> <span>Range: <a property="http://schema.org/rangeHint" 
>> href="http://schema.org/MedicalDevicePurpose">MedicalDevicePurpose</a></span>
>> 
>> 
> <span>Range: <a property="http://schema.org/rangeIncludes"
>> href="http://schema.org/Thing">Thing</a></span> </div>
>> 
>> 
>> The documentation could then list the formal range (Thing) and popular 
>> types for the range (e.g. MedicalDevicePurpose)
>> 
>> This requires just ten lines in the RDFa and tweaking the Python code and
>> Jinja templates that generate the documentation.
>> 
>> Martin
>> 
>> -------------------------------------------------------- martin hepp 
>> e-business & web science research group universitaet der bundeswehr
>> muenchen
>> 
>> e-mail:  martin.hepp@unibw.de <mailto:martin.hepp@unibw.de> phone:
>> +49-(0)89-6004-4217 <tel:%2B49-%280%2989-6004-4217> fax:
>> +49-(0)89-6004-4620 <tel:%2B49-%280%2989-6004-4620> www:
>> http://www.unibw.de/ebusiness/ (group) http://www.heppnetz.de/
>> (personal) skype:   mfhepp twitter: mfhepp
>> 
>> 
>> 
>> 
>> 
>> On 19 Jan 2015, at 18:18, Dan Brickley <danbri@google.com 
>> <mailto:danbri@google.com>> wrote:
>> 
>>> Hi Simon,
>>> 
>>> Thanks for these! I've opened Github issues for most of them, though I 
>>> take your point that there are more out there.
>>> 
>>> On 18 January 2015 at 17:54, Simon Spero <sesuncedu@gmail.com
>> <mailto:sesuncedu@gmail.com>> wrote:
>>>> 1:  The range of schema:purpose has no purpose. MedicalDevicePurpose
>>>> OR Thing  = Thing
>>> 
>>> https://github.com/schemaorg/schemaorg/issues/233
>>> 
>>>> 2: The range for schema:trailer includes MovieGameSeries
>>> 
>>> https://github.com/schemaorg/schemaorg/issues/234
>>> 
>>>> 3: schema:musicBy has a much smaller domain than actor or director
>>> 
>>> https://github.com/schemaorg/schemaorg/issues/235
>>> 
>>>> 4: The range of foodEstablishment is  FoodEstablishment or Place; 
>>>> but: FoodEstablishment is a subclass of LocalBusiness LocalBusiness
>>>> is a subclass of Place,
>>> 
>>> On this one I'm more sympathetic to Martin Hepp's point. Many local 
>>> businesses have foody aspects to them but it isn't always feasible to 
>>> make that explicit. However I'm wary of slipping into using 
>>> rangeIncludes and domainIncludes assertions purely as a UI 
>>> configuration language  for the Web site.
>>> 
>>>> Lots, lots more.
>>> 
>>> Feel free to fwd or bug-file the entire horror!
>>> 
>>> We have some very basic unit tests expressed in SPARQL -
>>> 
>> https://github.com/schemaorg/schemaorg/blob/master/tests/test_graphs.py#L97
>> 
>> etc. which ought to catch more of these (e.g. mentions of types that
>>> don't have definitions should help avoid types). This currently 
>>> requires Python RDFLib for the SPARQL tests, and I have had no success 
>>> making SPARQL 1.1 property paths work as advertised, which I hoped 
>>> might allow some basic matching against hierarchy.
>>> 
>>> cheers,
>>> 
>>> Dan
>>> 
>>>> + The number of children (and adults) for which a Lodging
>> reservations can be made can be a floating point number.
>>> https://github.com/schemaorg/schemaorg/issues/232
>>> 
>> 
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Received on Thursday, 22 January 2015 07:48:08 UTC

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