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Re: RDF 1.1 Lite Issue # 2: property vs rel

From: Manu Sporny <msporny@digitalbazaar.com>
Date: Sat, 22 Oct 2011 16:49:44 -0400
Message-ID: <4EA32C68.7080606@digitalbazaar.com>
To: public-vocabs@w3.org
On 10/22/2011 01:38 PM, Guha wrote:
> Google announced supported RDFa in 2009. One of the startling
> discoveries we made was that the error rate (i.e., webmasters marking
> up their pages to say X when the really meant to say Y) was about 3
> times as much as it was for other formats (which include
> microformats, sitemaps, Google shopping feeds, etc.). The error rate
>  is/was so bad that we had resort to highly non-scalable techniques
> like having humans look at the markup on each site to make sure it
> said what the page said. More than 40% of the errors had to do with
> the confusion between rel and property.

That is startling. Could you please publish the data and analysis
publicly so that those on this list may look at it and analyze it? We 
have a couple of approaches that we've discussed over the past 6+ years 
that could be applied if we knew exactly /how/ people were getting the 
markup wrong.

I will also note that this particular data was never brought to the
attention of the RDFa Working Group. When did you know about these
errors? Why did you not share the data when you came across it? I ask
because it would've impacted the design of RDFa 1.1 if you had shared
this data with us at the time.

> It is important to note that this data is from a very large sample
> (10s of millions of pages) taken from Schema.org's target audience:
> webmasters of sites that are by and large not about technical stuff.

A list of URLs would be great along with a technical analysis of all of
those URLs. Specifically, the following data would be very helpful:

* How frequent was the use of @rel vs. the use of @property?
* When @rel was used, was it used in chaining or was it used to
   simply refer to an external resource?
* In the Microformats and Creative Commons cases
   (rel="license", rel="tag", etc.) did people get @rel wrong?
* How frequently does @rel and @property exist on the same element?
* How frequently is @property used when @rel should have been used
   instead?
* How frequently is @rel used when @property should have been used
   instead?

Answering these questions will help us understand how the spec should 
change.

> We really don't want to get into whether there is a distinction
> between rel and property at a theoretical level.

Who is "we" in this case? The RDFa WG does not want to get into a 
theoretical debate either. We care about authors easily generating good, 
valid data.

> But the bottom line remains that as long as
> the error rate in RDFa usage does not go down dramatically, it is not
> a viable option for us.

Who is "us" in this case?

> The current proposal takes a step in the
> right direction, but several big issues, like the removal of the
> distinction between rel and property still need to be addressed.

Could you please detail every one of those "big issues"?

-- manu

-- 
Manu Sporny (skype: msporny, twitter: manusporny)
Founder/CEO - Digital Bazaar, Inc.
blog: Standardizing Payment Links - Why Online Tipping has Failed
http://manu.sporny.org/2011/payment-links/
Received on Saturday, 22 October 2011 20:50:14 GMT

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