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Re: Microdata design philosophies

From: Tab Atkins Jr. <jackalmage@gmail.com>
Date: Fri, 16 Oct 2009 16:39:42 -0500
Message-ID: <dd0fbad0910161439w69ee40bm82bfe33d058c0aea@mail.gmail.com>
To: martin@weborganics.co.uk
Cc: Leif Halvard Silli <xn--mlform-iua@xn--mlform-iua.no>, Ian Hickson <ian@hixie.ch>, public-html@w3.org
On Fri, Oct 16, 2009 at 4:19 PM, Martin McEvoy <martin@weborganics.co.uk> wrote:
> look at this example:
> http://www.whatwg.org/specs/web-apps/current-work/multipage/microdata.html#the-basic-syntax
> <div itemscope id="amanda"><itemref refid="a"><itemref refid="b"></div>
> <p id="a">Name: <span itemprop="name">Amanda</span></p>
> <div id="b" itemprop="band" itemscope id="jazzband"><itemref
> refid="c"></div>
> <div id="c">
> <p>Band: <span itemprop="name">Jazz Band</span></p>
> <p>Size: <span itemprop="size">12</span> players</p>
> </div>
> What is the above example trying to attempt?

It's marking up someone's participation in some band, apparently.

> What does itemscope mean?

Have you read the Microdata section?  @itemscope says "This chunk of
html defines a chunk of microdata."  It scopes any children of the
element to be part of that parent item (rather than being just random
unconnected bits of data).

> look at those funny little bits of mark up <itemref refid="a"><itemref
> refid="b">, do itemref and refid confuse you? again what do they mean?

Again, have you read the Microdata section?  <itemref> allows you to
include data from elements that aren't children of the @itemscope.

> Look at every bit of content for example <span itemprop="size">12</span>,
> what does size mean or band or any of the attribute contents?
> How Is a newcomer to HTML or the semantic web going to make of all that?
> Does the above seem a little much just to mark up around 18 characters of
> data?
> Do you think a search engine will understand the above example, knowing that
> they cant reason like humans.

It's some example vocabulary used to illustrate the principls.

Assume, for a moment, that a similar vocabulary existed in RDF, and
the example was instead marked up in RDFa.

How is a newcomer to HTML or the semantic web going to make of all that RDFa?
Doesn't the RDFa seem a bit much just to mark up around 18 characters of data?
Do you think a search engine would understand the RDFa, knowing that
they can't reason like humans?

All of these concerns you have are *exactly* applicable to RDFa, or
really *any* method of marking up metadata in a page (such as CRDF,
GRDDL, etc.).

It appears that you don't have any real understanding of what
Microdata is or how it works, or what RDFa is or how it works for that
matter.  Several times you've given some argument for why Microdata is
bad and RDFa is good, when the argument given applies equally to both
of them.  There are differences between the two syntaxes that can be
pointed to and have their relative merits argued, but you haven't done
that yet.

Received on Friday, 16 October 2009 21:40:30 GMT

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