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RDFa Last Call Comment: Better name than 'instanceof' is needed

From: John Boyer <boyerj@ca.ibm.com>
Date: Mon, 17 Mar 2008 13:22:58 -0700
To: public-rdf-in-xhtml-tf@w3.org
Message-ID: <OFDE92A6DF.4593D46D-ON8825740F.006E30BD-8825740F.006FF798@ca.ibm.com>
RDFa is designed to provide a set of attributes for including RDF 
information into XHTML documents.

XHTML2 is designed to work with XForms.

Central to the operation of XForms is an "instance", which is a block of 
XML data over which the XForm operates.  This name for data was obtained 
from the XML Schema working group as the "standard" way to refer to an 
occurrence of XML conforming to a given schema as an "instance" of that 
schema.  In XForms, one can have an instance without physically 
associating a schema with it, or even having expressed the schema, but 
that is beside the point as one might reasonably regard such occurrences 
as an authoring convenience for an implied schema.

The main point is that these things are called "instances" because you 
can, in principle at least, *instantiate* a template description, much 
like creating a new object from a class definition.  The XForms instances 
can, in principle at least and often in practice, be viewed as an 
instantiation of a template defined by a schema.  In the future, I am 
hoping we get better at embedding the instantiation operation itself into 
XForms.

Instantiation does not appear to be what is happening in the case of RDFa. 
 Instead, the element to which you attach "instanceof" is something to 
which you simply seem to be attaching some RDF type information.  A name 
that more accurately reflects that behavior would be preferable.

Lest you think this is just picking a nit, a secondary reason for 
requesting a change here is that I would like to avoid any confusion 
between use of the word instance as it applies to XForms versus its use 
with RDFa.  Although the W3C will not always be able to see name conflicts 
coming in advance, we should at least take action when we do see a problem 
coming in advance.  We have been especially charged by W3 management with 
easing the authoring experience of XHTML and XForms going forward, and I 
notice to that end that the RDFa attributes are not namespace qualified. 
The XForms syntax work being done in XForms 1.2 will likely allow adoption 
into XHTML without namespace qualification into the XForms namespace. This 
eases authoring but accentuates the possibility of confusion when these 
vocabularies contain similar names, if not exact name conflicts, for 
different concepts.
 
Thank you,
John M. Boyer, Ph.D.
Senior Technical Staff Member
Lotus Forms Architect and Researcher
Chair, W3C Forms Working Group
Workplace, Portal and Collaboration Software
IBM Victoria Software Lab
E-Mail: boyerj@ca.ibm.com 

Blog: http://www.ibm.com/developerworks/blogs/page/JohnBoyer
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Received on Monday, 17 March 2008 20:23:44 UTC

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