W3C home > Mailing lists > Public > public-vocabs@w3.org > November 2011

Re: Need for a new type Activity

From: Martin Hepp <martin.hepp@ebusiness-unibw.org>
Date: Tue, 1 Nov 2011 07:45:37 +0100
Cc: Dan Brickley <danbri@danbri.org>, "public-vocabs@w3.org" <public-vocabs@w3.org>
Message-Id: <0C393186-3919-4935-9695-F83F369B48AF@ebusiness-unibw.org>
To: Roy Lachica <roy@webnodes.com>
Hi Roy:

I think there is a trade-off between:

1. The stability of schema.org (or any other schema) and
2. the complexity of using multiple namespaces.

A bit of background on this is given in my papers [1, 2].

schema.org and any other Web-scale vocabulary can hardly maintain an up-to-date inventory of value definitions across all industries. I personally think that referring to DBPedia (or recommending Wikipedia lemmata) is acceptable for Web developers, given the fact that it provides ca. 2 Mio. human-readable, high-quality definitions for entities.

Another option would be for schema.org to maintain a special Wiki for defining such types, but I can tell you from our work on the MyOntology project [3,4] that the problem with such an approach is that it will always be way less complete than Wikipedia, in terms of entries, translations, definitions, etc.

This is why www.productontology.org, the type extension for schema.org and GoodRelations, now uses Wikipedia lemmata directly.


[1] Possible Ontologies: How Reality Constrains the Development of Relevant Ontologies, in: IEEE Internet Computing, Vol. 11, No. 1, pp. 90-96, Jan-Feb 2007 (invited).
PDF: http://www.heppnetz.de/files/IEEE-IC-PossibleOntologies-published.pdf

[2] E-Business Vocabularies as a Moving Target: Quantifying the Conceptual Dynamics in Domains, Proceedings of the 16th International Conference on Knowledge Engineering and Knowledge Management (EKAW2008), September 29 - October 3, 2008 (forthcoming), Acitrezza, Italy, Springer LNCS, Vol. 5268, pp. 388-403. 
PDF: http://www.heppnetz.de/files/ConceptualDynamics-EKAW2008-CRC-final6.pdf

[3] http://www.myontology.org/ (no longer maintained, but the code base is still used by the project 

[4] myOntology: The Marriage of Ontology Engineering and Collective Intelligence, Proceedings of the ESWC 2007 Workshop "Bridging the Gap between Semantic Web and Web 2.0", June 7, 2007, Innsbruck, Austria.
PDF: http://www.heppnetz.de/files/SiorpaesHepp-myOntology-eswc07-camready.pdf

On Oct 31, 2011, at 1:10 PM, Roy Lachica wrote:

> Thank you Adrian, Dan and Martin.
> Martin
> Using external identifiers e.g. from DBPedia or Freebase sounds like a good solution. However the drawback of this approach is that it creates confusion for "ordinary" web developers and webmasters. At the moment Schema.org is so simple that "anyone" can use it. If we begin to rely on webmasters to use external identifiers and begin to encourage webmasters to mix vocabularies you create confusion about what identifiers and vocabs to use, how to use them, where to find them, etc. 
> Dan
> I understand adding all these subtypes pose all kinds of problems such as ontological and perhaps even political issues. Anyway if you at least just add the new type Activity webmasters could use extensions to define the subtypes so you (Schema.org) don't have to take a stance on what subtypes to define. In a  bottom up way you could then later define the sub types based on the extensions we provide.  
> I would also guess that type-subtypes are better than enumerations here since it would allow for further sub types. Activity sub types might perhaps also have different properties. 
> I strongly believe a new type Activity would be a great contribution as a large portion of the content on the web today is about activities. E.g. pages about working, talking, eating, running, sleeping, drinking, learning, dancing, teaching, driving, making love, fighting, bird watching etc. 
> A place to see the extensions used by webmasters would be really cool.
> A webpage that shows all extensions with the number of sites using it and the number of pages would bring more transparency to the process.
> Best regards
> .roy
> -----Original Message-----
> From: Martin Hepp [mailto:martin.hepp@ebusiness-unibw.org] 
> Sent: 28. oktober 2011 20:49
> To: Dan Brickley
> Cc: Roy Lachica; public-vocabs@w3.org
> Subject: Re: Need for a new type Activity
> I can strongly recommend the approach taken in e.g. http://purl.org/vso/ns:
> 1. Define a class for the type of a value 2. Recommend DBPedia or Freebase IDs for the individuals, if they exist.
> 3. If there is no standardized identifier yet, Web site owners can define one locally and hope that clients can do the entity consolidation.
> This decouples the maintenance of the schema from the evolution of new values.
> See e.g.
>   http://www.heppnetz.de/ontologies/vso/ns.html#FuelTypeValue
> Best
> Martin
> On Oct 28, 2011, at 2:20 PM, Dan Brickley wrote:
>> Hi Roy,
>> On 26 October 2011 19:24, Roy Lachica <roy@webnodes.com> wrote:
>>> Hi
>>> I was just adding Schema.org for a tourist site. In particular activities (Things to do at a location) and found a need for an Activity type.
>>> Many tourism websites separate tourist activities from tourist sites (what to do from what to see).
>>> Existing types such as http://schema.org/Event seem to be meant for a single event happening at a certain time at a certain location.
>>> http://schema.org/TouristAttraction don't really match for activities such as shopping and eating out? From Wikipedia: "A tourist attraction is a place of interest where tourists visit, typically for its inherent or exhibited cultural value, historical significance, natural or built beauty, or amusement opportunities."
>>> A page about Hiking should have links to places where you can go hiking, but the activity hiking itself is not really a tourist attraction?
>>> I would like to add activities that are also relevant in a non-tourist setting. Using TouristAttraction (typically used for things you go to see) therefore seem wrong. TouristAttraction is also a sub type of Place. Many activities are place independent.
>>> I would guess that search engine queries like "What to do in Rio" are just as much used as "What to see in Rio".
>>> When searching for Shopping it would be nice to specify that i mean the activity of shopping so I can get a list of pages about shopping rather than a list of online shops.
>>> There are also many sites that contain general non-tourist activities that could benefit from an Activity type.
>>> By having an activity type, search engine users can differentiate between football as an activity, a football club or the object football.
>>> I would therefore like to suggest the type: Activity  (description: 
>>> Something you can do at will, regularly or perhaps once in a 
>>> lifetime)
>>> I am sure someone else has better suggestions for sub types, 
>>> properties and descriptions. I was not able to find a good taxonomy 
>>> or vocabulary but here's a few suggestions for sub types [...]
>> Thanks for raising this, and the suggestions. Before jumping into 
>> those specifics I think it's worth pointing out a difficulty we'll all 
>> have here: if Schema.org starts to include big enumerated lists it 
>> could become rather hard to maintain in the future. This was discussed 
>> at last month's workshop; Guha and others suggested that Schema.org 
>> should avoid such enumerations. Where they exist already in well 
>> established systems, Schema.org could serve as a documentation hub, 
>> pointing to those pre-existing lists. In this case, the scope of the 
>> list is quite broad --- it's all things of things that people do, or 
>> do for leisure.
>> One possibility to investigate here is to look to larger collections 
>> to add in such detail. For example using a collection like Wikipedia 
>> (or it's RDFization as DBpedia, or the proposed Wikidata work; or 
>> Freebase...). At some point with Schema.org we have to say "ok, 
>> enough! let's cut over to a larger community-maintained dataset". It 
>> is not exactly clear where that cut point should be. There are points 
>> within the current schema (eg. http://schema.org/HairSalon) where you 
>> could argue the limit has been reached.  I wonder how many of the 
>> activity-types listed here have nice solid obvious Wikipedia URLs 
>> associated with them (and which are handled as wiki Categories), and 
>> also whether they are modeled/described in anything like a consistent 
>> manner there...
>> cheers,
>> Dan
Received on Tuesday, 1 November 2011 06:46:13 UTC

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