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RE: Conditional versus Optional: Preliminary Observations

From: jon gunderson <jongund@ux1.cso.uiuc.edu>
Date: Thu, 22 Feb 2001 22:38:01 -0600 (CST)
To: "Hansen, Eric" <ehansen@ets.org>
cc: "'oedipus@hicom.net'" <oedipus@hicom.net>, w3c-wai-ua@w3.org
Message-ID: <Pine.GSO.4.10.10102222234580.22188-100000@staff2.cso.uiuc.edu>
I don't think we need to mention the authors intent in the definition.  I
think we say that it is content the author provides that will be rendered
given a certain set of circumstances that include user agent capabilities,
user perferences and the bandwidth of the informational exchange.  

Jon


On Thu, 22 Feb 2001, Hansen, Eric wrote:

> Gregory,
> 
> The suggestion is interesting. If the change were made, would the definition
> capture what we mean?
> 
> New, tentative definition of "Conditional content":
> 
> Conditional content is content that the author does not intend the
> user agent to render by default, but that the author does intend
> to make available to the user through the user interface under
> certain conditions. Some mechanisms for providing conditional
> content include the "alt" attribute and the OBJECT element in
> HTML, and the test attributes of SMIL 1.0 and SMIL 2.0.
> 
> The rendering semantics (when and where) of conditional content may
> be well-defined in some cases (e.g., "alt" and OBJECT in HTML)
> and less well-defined in others (e.g., "title" in HTML).
> 
> Note: The Web Content Accessibility Guidelines 1.0 requires that
> authors provide text equivalents for non-text content. This is
> generally done by using the conditional content mechanisms of a
> markup language.
> 
> Thanks!
> 
> - Eric
> 
> Old defintion of "Optional content" per 
> http://lists.w3.org/Archives/Public/w3c-wai-ua/2001JanMar/0249.html
> 
> -------------------------------------------------
> Part III: Definition of optional content
> -------------------------------------------------
> 
> Optional content is content that the author does not intend the
> user agent to render by default, but that the author does intend
> to make available to the user through the user interface under
> certain conditions. Some mechanisms for providing optional
> content include the "alt" attribute and the OBJECT element in
> HTML, and the test attributes of SMIL 1.0 and SMIL 2.0.
> 
> The rendering semantics (when and where) of optional content may
> be well-defined in some cases (e.g., "alt" and OBJECT in HTML)
> and less well-defined in others (e.g., "title" in HTML).
> 
> Note: The Web Content Accessibility Guidelines 1.0 requires that
> authors provide text equivalents for non text content. This is
> generally done by using the optional content mechanisms of a
> markup language.
> 
> > -----Original Message-----
> > From: oedipus@hicom.net [mailto:oedipus@hicom.net]
> > Sent: Thursday, February 22, 2001 4:58 PM
> > To: w3c-wai-ua@w3.org
> > Subject: Conditional versus Optional: Preliminary Observations
> > 
> > 
> > Conditional versus Optional: Preliminary Observations
> > 
> > in the minutes from the 22 February 2001 telecon [reference 1], the 
> > following exchange was recorded:
> > 
> > quote
> >   GR: "Required optional content" is a little weird.
> > 
> >   IJ: Good point! 
> > 
> >   Action IJ: Find clearer wording.
> > 
> >   GR: I propose changing "optional content" to "conditional content".
> >       I think that conditional doesn't presume that one form of
> >       content is preferred over another.
> > 
> >   IJ: I don't think "optional" suggests that optional content
> >       is lower class.
> > unquote
> > 
> > 1. required bits are not "optional"--"required optional" is an 
> > oxymoron; what is "optional" is the discretionary portion of 
> > the requirement--for example, in the HTML4/XHTML world, deciding 
> > on appropriate ALT text for the IMG element...  the A, the L, 
> > the T, the equals sign, and a pair of quotes are required--what 
> > goes between the quotes is the optional bit...
> > 
> > 2. "conditional" because what is delivered to the requesting UA 
> > is the derivative of the conditions surrounding slash containing 
> > slash initiating the transaction; moreover, the conditions under 
> > which content is delivered (or in which content is capable of 
> > being delivered) are not always/necessarily "optional", as they 
> > may (or are quite likely to) include both those over which the 
> > user has either no or limited control, or of which the user is 
> > ignorant (in a non-pejorative sense)--conditions can also be 
> > predicated upon explicit user choice; server side filters and 
> > transformations, including processing by proxy servers; 
> > configurations slash settings; hardware limitations; language 
> > preference (accept) settings; functional limitations, 
> > environmental limitations; markup support slash standards 
> > compliance ; etc.; the point is that the "content" (the message) 
> > is capable of being delivered by a number of potential messengers 
> > (content/file types), depending upon which is most appropriate--
> > e.g. when certain conditions (no matter their source) apply, send 
> > slash receive slash expose slash render X, not Y or Z, but if X 
> > does not exist slash has not been provided, Q will be acceptable...
> > 
> > 3. "conditional" is completely neutral--no need to speak of 
> > equivalencies; doesn't champion slash pit one form of content 
> > slash modality over another, as it doesn't matter why the 
> > conditions exist, only that the UA respond to them 
> > appropriately, by providing content in the most appropriate 
> > content-type slash form slash modality, whether due to an 
> > explicit request for a particular content type, the explicit 
> > exclusion of unsupported slash unusable slash unwanted content 
> > types, or by preference slash cascade order
> > 
> > 4. the term "conditional" captures the nuances of the term far 
> > more concretely, and far less ambiguously, than "optional", as 
> > it incorporates user configuration; negotiation transactions 
> > (such as those based on CC/PP, accept headers, etc.); SWITCH- 
> > and SWITCH-like mechanisms; the rendering order of nested 
> > OBJECT elements; SMIL test attributes; and the CSS cascade, to 
> > name but a few
> > 
> > 5. "optional" is a dangerous term because the plain English 
> > language definition of the word "optional" is, according to 
> > the online edition of Webster's (http://www.m-w.com)
> > 
> > quote
> >   involving an option : not compulsory
> > unquote
> > 
> > which (at least to my ears) eliminates the term from contention, 
> > as use of the ALT attribute for the IMG element is compulsory in 
> > HTML4/XHTML1...
> > 
> > gregory.
> > 
> > PS: i know that the example is technology-specific, but that's 
> > simply because the case of IMG is the most familiar and clearest 
> > illustration of the point...
> > 
> > References:
> > 
> > [1] (long URI warning!) 
> > http://lists.w3.org/Archives/Public/w3c-wai-ua/2001JanMar/0258.html
> > -------------------
> > Email sent using AnyEmail from http://www.hicom.net
> > 
> 
Received on Thursday, 22 February 2001 23:38:05 UTC

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