- From: David Orchard <dorchard@bea.com>
- Date: Sat, 5 Oct 2002 00:26:42 -0700
- To: <noah_mendelsohn@us.ibm.com>, "'Tim Bray'" <tbray@textuality.com>
- Cc: <Mike.Champion@SoftwareAG-USA.com>, <www-tag@w3.org>
Noah, I think Tim's shorter version is more appropriate. Value is always relative to the cost/benefits associated with a given action or non-action, and it's impact to the overall state of affairs in any given area. I tend to prefer shorter and more concise statements in these kinds of areas. Personally, I think that's one of the things that TimB does very well, creating succinct and direct statements. The 80/20 rule applied to statements if you will. Having said that I certainly and heartily agree with analyzing and weighing the costs and benefits of each style of linking. I think there ought to be a running list of different "features" and how they might be expressed in various linking syntaxes. I kind of imagine about 20 different features, and about 5 different schemes with a matrix of syntaxes. But then I've always been "lists" kind of guy. Cheers, Dave > -----Original Message----- > From: www-tag-request@w3.org > [mailto:www-tag-request@w3.org]On Behalf Of > noah_mendelsohn@us.ibm.com > Sent: Friday, October 04, 2002 8:11 PM > To: Tim Bray > Cc: Mike.Champion@SoftwareAG-USA.com; www-tag@w3.org > Subject: Re: XHTML & hyperlinking opinions (long, sorry) > > > > Tim Bray writes: > > >> I think reasonable disagreements are of the > >> form "no, that's not a valuable thing to add" > > I agree that's the key issue, but suggest a reformulation: > > "I think reasonable disagreements > are of the form 'no, trading off the > value gained against whatever > drawbacks, it's not on balance a > good thing to add.'" > > Xlink presumably has value in at least some situations. I think the > question is: how often, how much, and how does that value compare to > whatever downsides it might have? We need those answers in > general and > for XLink-for-XHTML in particular. > > We also have to be clear on what we're advertising as the > value gained > from any particular proposal. What I think I've heard argued > for as the > benefit of XLink includes at least the following 3 points > (I've thrown in > personal opinions on a few, but they're not central to my > main suggestion > which is: list the proposed benefits& drawbacks, and do a > dispassionate > pro/con analysis): > > ----Possible benefits of XLink for XML --------- > ------in general and XHTML in particular-------- > > 1. A linking mechanism that is common across all (or most) > vocabularies > and applicable to all uses in those vocabularies, so that it can be > recognized independent of context. > > This is just as all attributes are represented uniformly, and we can > therefore build tools that work on any attribute in any > vocabulary. The > claim would be that we need the same uniformity for links, > presumably so > we can build things like generalized, vocabulary-independent link > manipulation tools. > > (I happen not to be convinced that this is in general > practical, because I > think links have a semantic that's not in general trustworthy without > knowing the application context. For example, see my earlier > posting on > undo lists containing deleted data in compound document > structures [1]. > You don't really understand a link, I claim, if it's in a > structure that > the application uses to represent deleted data. Or conversely, a > construction like XLink might be restricted to use in > situations where > context doesn't matter, implying that when I move deleted > text to the undo > list, I have to change from XLink to something else (so that > generalized > tools won't think this document is still making a link.) So, > I remain > suspicious of the need for or practicality of a common way to > encode all > links.) > > 2. A richer linking mechanism with multi-way links, third > party links etc. > This seems to have value, at least in principle, and > figuring out how to > do it once and reusing that insight where appropriate seems > to make sense. > Whether the value of trying to actually get to the level of common > serializations of these constructs in application-specific > vocabularies > outweighs the complexity and inconvenience, I'm not sure. > > 3. A generalized means of providing presentation hints, what > I believe > XLink calls behavior attributes. (I have some nervousness > about these > too, in that I see much (not all) XML as being on the model side of a > model/view architecture. Insofar as these attributes > encourage embedding > of presentation hints in the model, I get a bit nervous. > That said, XLink > layers them quite well, and makes them optional, and they > certainly are > potentially applicable to presentation-oriented vocabularies such as > XHTML. Still, I'm not sure how much value there is in > generalizing them > across vocabularies: probably some, but I don't see it as broadly > applicable to all XML, which is what I thought was advertised > for XLink.) > > ------------------------------------------------- > > So: for Xlink, I think we have to answer Tim's question (as > reformulated) > with respect to the three purported benefits above. I > personally don't > have a strong opinion pro or con on XLink, but am interested > in seeing the > questions stated clearly so we can get to an answer. Maybe this is a > piece of the formulation? > > Noah > > [1] http://lists.w3.org/Archives/Public/www-tag/2002Sep/0178.html > ------------------------------------------------------------------ > Noah Mendelsohn Voice: 1-617-693-4036 > IBM Corporation Fax: 1-617-693-8676 > One Rogers Street > Cambridge, MA 02142 > ------------------------------------------------------------------ > > >
Received on Saturday, 5 October 2002 03:30:58 UTC