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Re: Data blocks, not marked up content

From: Thomas Steiner <tomac@google.com>
Date: Mon, 10 Oct 2011 10:24:24 +0200
Message-ID: <CALgRrLmSyOTj8Vow0p9UJj=bUhEpX8pN33BWXgV5CZCVCaPHhg@mail.gmail.com>
To: Martin Hepp <martin.hepp@ebusiness-unibw.org>
Cc: public-html-data-tf@w3.org, Ivan Herman <ivan@w3.org>, Lin Clark <lin.w.clark@gmail.com>, jeni@jenitennison.com, gavin@topquadrant.com
Hi Martin, all,

> A bit of background why we think that invisible markup is an important option for
> 1. non-trivial data structures, in particular if they
> 2. do not correspond to the organization of the visible content is here:
> Hepp, Martin; García, Roberto; Radinger, Andreas: RDF2RDFa: Turning RDF into Snippets for Copy-and-Paste, Technical Report TR-2009-01, 2009.
> A PDF is here: http://www.heppnetz.de/files/RDF2RDFa-TR.pdf
> This is even more important if you face messy, complicated HTML markup as in article detail pages, because the heuristics for dealing with RDFa in lax HTML are more reliable if the RDFa snippet itself is a self-contained block - e.g. forgotten closing elements cannot break the structure of the data.

Note: I did not write that you should never ever use hidden mark-up.
There are a lot of valid use cases, or rather, constraints, that even
force you in the hidden mark-up corner. We simply should not encourage
this behavior in my humble opinion. Just to clarify…

> By the way, despite that Google discourages invisible markup officially, they ingest and display it, as long as it comes from an otherwise trustworthy page / domain name space. I have lots of examples for this ;)

Again, clarifying that I explicitly took my employer's hat off, and I
also did not doubt that hidden mark-up works. Simply speaking, if
Webmasters have the choice between hidden mark-up and visible mark-up
(data mark-up that is), then the default reaction should be to give
visible mark-up priority, recommendation-wise.

I think we fully agree :-)


Thomas Steiner, Research Scientist, Google Inc.
http://blog.tomayac.com, http://twitter.com/tomayac
Received on Monday, 10 October 2011 08:25:42 UTC

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