- From: Phil Archer <parcher@fosi.org>
- Date: Thu, 06 Nov 2008 15:52:32 +0000
- To: Public MWBP <public-bpwg@w3.org>
- CC: Public POWDER <public-powderwg@w3.org>
Hi Jonathan ad all, comments in line below. This by way of a written version of the comments just made during the MWBP call. The content of this e-mail is given as a response to the one Jonathan posted to the POWDER public list but also replies to similar comments he posted to the MWBP list. 전종홍 wrote: > Dear all, > > Currently, we (me and korean community) are trying to apply the machine-readble > mobileOK trustmark (like POWDER) within our pilot service. Good - I hope it works for you! > > But, the trustmark of POWDER style seems to be not easy to use on current browser. > > I think there are some issues to use of POWDER-based trustmarks. > - not simple, complex That's a matter of opinion of course. We have tried very hard to make POWDER as simple to create and use as possible. A Description Resource has to define the scope (what is described), the description itself and for all that to be attributed to an identified agent of some kind. Those 3 elements obviously put a lower limit on how simple it can be. > - cannot apply to current mobile browser True. Using POWDER directly implies some development work of come kind. A POWDER Processor is the way we suggest to go from a POWDER doc to 'native RDF', and GRDDL gets you from POWDER to something very close to what can be understood in OWL reasoners. > - cannot append within (X)HTML file True. This was an early decision. Our use cases, including the mobileOK one, pointed us to separating the description and the content it describes. Remember that POWDER is designed to describe lots of content at once so that you only have to process it once to know that, say, the whole of example.org is mobileOK. We didn't want it to be necessary to fetch and parse a resource to find its description - you often want to know before hand whether you want to bother fetching and parsing a resource for a particular application or delivery context. > - should manage separated POWDER xml file See above. This was very much a deliberate design choice. > > For this reason, I think we need to consider > the simple mobileOK trustmark that like microformat style. > > So, I was starting to define a mobileOK trustmark of microformat style. > > http://docs.google.com/Doc?id=dhpvgnmn_68dwzhntdt > > It is simple, but also similar and compatible with POWDER. > > It has some cons ... > - simple, not complex Again, a matter of opinion (i.e. it's simpler if you're a microformats person, more complex for others) > - compatible with POWDER Up to a point in that it uses the same constructs, yes, but it puts an overhead on processing that I would suggest can be avoided by keeping the data separate. > - can use widely available browsers That's a strong plus point of course. > - can embed in (X)HTML Well, as you'll have guessed, I don't personally see that as a positive. The examples you give in your document add several lines of code to an XHTML document, code that would need to be repeated in every mobileOK document - which, surely, goes against one of the general aims of mobile content provision which is to keep page weight as low as possible? For this reason, I think an approach closer to the RDFa model would be better if you want to embed the mobileOK claim in the document. I know it's about to disappear from the next version of the mobileOK scheme but take a look at [1]. That example adds in the mOK namespace and uses the typeof attribute [2] to link to the 'Conformant' vocabulary term. Now... one thing that this approach loses by not using POWDER, that your microformat retains, is the attribution. This is critical for POWDER so I'm glad you've retained it! Whether the microformat approach is better than POWDER depends what you're trying to do of course. If you want to include a claim in an XHTML document that it is mobileOK, then the microformat approach works - although I think it might make a page not mobileOK in the process. A more compact mark up would be better - and RDFa does the job nicely (although I dare say a microformat could do the job just as well). Link elements work in all versions of HTML and achieve the same thing. HTTP link headers are efficient for all formats, not just HTML. If you want to declare that a lot of resources have been found to be mobileOK and that anyone that wants to verify the claim is welcome to do so by following various links, then I think a separate POWDER file offers a better approach. A couple of specifics about your document: 1. It's wrong to suggest that http://authority.example.org/company.rdf#me describes W3C. The URI is a made up 'example' one. 2. In your first POWDER example you've quoted the currently published version which has the made-up URI for the mOK logo. Please update that as you have in the other examples. 3. Your Example 3 uses the sha1sum property (element) which comes from our example where one DR certifies another. It would be wrong to include a hash as a description of, as you have it, lots of things on example.com and example.org. Obviously I and the rest of the WG are delighted that you've taken the time to study POWDER and it's good to see it being talked about and promoted. I do, however, think that the re-expression of it as a microformat risks losing sight of what POWDER was designed to do and therefore to retain all its features in a new environment may be pushing it too far. Better to take what you want and live with what you lose on the way, knowing that if you want the full feature set, especially in terms of processing efficiency and page weight, you need the real thing. Cheers Phil. [1] http://www.w3.org/2005/MWI/BPWG/Group/Drafts/mobileOK-Trustmark/20081017#rdfaClaim [2] http://www.w3.org/TR/rdfa-syntax/#rdfa-attributes > > I think it will be helpful to spread the POWDER based applications. > what do you think about it ? > > Best Regards, > > --- Jonathan Jeon -- Phil Archer w. http://philarcher.org/
Received on Thursday, 6 November 2008 15:53:08 UTC