[whatwg] RDFa Basics Video (8 minutes)

[Ben Adida]

Kristof Zelechovski wrote:
> We have two options for having both human-readable and machine-readable
> information in a document: write the structure and generate the text or
> write the text and recover the structure.  At the very least, if you insist
> on having both, there must be a mechanism to verify that they are
> consistent.

Why? Is there a mechanism for verifying that an RSS feed matches the
HTML blog? No, and oftentimes it doesn't, even though it is supposedly
generated from the same source.

In addition, sometimes the machine-readable content slightly differs
from the human-readable, e.g. with dates. Microformats deal with this,
and so does RDFa.

But, in general, with RDFa, since the human-rendered content is re-used
for machine-readability, your chances of a match are much higher than
with other mechanisms, like RSS in a separate file.

Consider:

  <h2 property="dc:creator">Kristof</h2>

The creator string "Kristof" is written only once, and plays both roles.

We just want to let authors express structured data. They may do it
wrong, just like they may write ugly web pages. But giving them the
ability makes for some powerful applications, as Manu has begun to
describe quite well.

-Ben