W3C home > Mailing lists > Public > www-rdf-interest@w3.org > September 2000

Re: Meaning of Alt

From: Ray Fergerson <fergerson@SMI.Stanford.EDU>
Date: Thu, 07 Sep 2000 16:27:09 -0700
Message-ID: <39B8244D.928162A9@smi.stanford.edu>
To: rdf interest <www-rdf-interest@w3.org>
Jonathan Borden wrote:
>     Reading the spec I see no support for any particular interpretation of
> Alt other than it represents one of a set of members. So
> {"red","green","blue"}, to me, represents a set. Seq implies on an ordered
> list of members, perhaps repeated. Alt implies one of the set. Why not allow
> the Schema designer the choice? Can actual harm result beyond an offending
> of sensibilities?

My confusion on this issue is the result of the following two
passages:

-------------
M&S, section 3.1:
Alternative might be used to provide alternative language translations
for the title of a work, or to provide a list of Internet mirror sites
at which a resource might be found. An application using a property
whose value is an Alternative collection is aware that it can choose
any one of the items in the list as appropriate.

M&S, section 3.2
An Alt container is required to have at least one member. This member
will be identified by the property _1 and is the default or preferred
value.
-------------

The examples in the first sentence and the phrase "any one of the
items in the list as appropriate" make it sound as if the items in the
list are meant to be more or less interchangeable.  Also the phrase
"preferred value" implies that the other values are more or less
equivalent.  The mirror site example is consistent with this
interpretation but the alternate language example is somewhat less so.

In my traffic light example I don't want a default value or a
preferred value.  I just want three possible values.  This doesn't
seem to be possible.

I may have completely misunderstand the spec and the intended function
of Alt.  I was just hoping for a little clarification of the intent. 
I suppose that I should be happy that others are unclear on this as
well...

Ray
Received on Thursday, 7 September 2000 19:25:08 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 7 December 2009 10:51:44 GMT