W3C home > Mailing lists > Public > public-vocabs@w3.org > May 2014

Re: Generic Property-Value Proposal for Schema.org

From: <martin.hepp@ebusiness-unibw.org>
Date: Fri, 2 May 2014 23:11:01 +0200
Cc: Aaron Bradley <aaranged@gmail.com>, kevin.polley@mutualadvantage.co.uk, W3C Web Schemas Task Force <public-vocabs@w3.org>, Jay Myers <jay.myers@bestbuy.com>, Mike Bergman <mike@mkbergman.com>
Message-Id: <D84F7CAD-D839-4422-9A52-32F8A5A0CD36@ebusiness-unibw.org>
To: Jason Douglas <jasondouglas@google.com>
Hi Jason:
On 02 May 2014, at 19:38, Jason Douglas <jasondouglas@google.com> wrote:

> Fine, but I think there's an aspect of that mechanism that would be a shame to drop, which is that it had some semantic scoping.  
> 
My proposal does not mean to drop the slash-based extension mechanism (while I personally think that it is a problematic one). The slash-based mechanism may work well for properties that are relatively close specializations of an existing property or type. But in case of a very broad property like "feature", a specialization like "fuelConsumptionInLitersPer100Km" does not add too much. Plus, it violates the Web Architecture principle of URI Opacity.

> I think it's a bad idea to have a completely generic bailout mechanism like this.  However, I have no issue with more localized bailouts for things like product specifications or sports statistics that do have common characteristics but a lot of variety and uniqueness.  You at least have some hope of being able to do something useful with that data.

Good. And yes, I too think that the mechanism is most useful if you know that the entity is a Product or Place. Though there may still be cases where even a code for the unit or knowing the min and max of a range will be a little semantics that go a long way:

<div itemscope itemtype="http://schema.org/Place">
  <span itemprop="name">Slow Cook International Hamburgers</span>
  <div itemprop="additionalProperty" itemscope itemtype="http://schema.org/PropertyValue">
	  <span itemprop="name">Next restroom</span>
	  <span itemprop="value">100</span>
	  <meta itemprop="unitCode" content="MTR"> meters
  </div>  
</div>

The fact alone that a property has a unit of meters (code MTR) means you could heuristically do nice stuff with this in Google maps (e.g. show a radius around the location of the place and label it with "next restroom", and then use user feedback to check whether this interpretation makes sense).

Or this one:

<div itemscope itemtype="http://schema.org/Product">
  <span itemprop="name">Hepp Cuckoo Clock</span>
  <div itemprop="additionalProperty" itemscope itemtype="http://schema.org/PropertyValue">
	  <span itemprop="name">Number of birds</span>
	  <span itemprop="minValue">2</span>
	  <span itemprop="maxValue">6</span>	  
  </div>  
</div>

While you may not want to standardize the property "number of birds" for cuckoo clocks in schema.org, having a lower and upper limit allows you to display a slider for faceted search. If you have a lot of entities that seem to be cuckoo clocks, you can do so pretty reliably.


>  Otherwise, there's little value over a bag of words.

As shown above, the conceptual distinctions provided by the extension may alone already be useful for a data consumer.


Martin
Received on Friday, 2 May 2014 21:11:41 UTC

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