- From: Al Gilman <asgilman@iamdigex.net>
- Date: Sun, 21 Oct 2001 12:39:10 -0400
- To: "Jim Ley" <jim@jibbering.com>, <w3c-wai-er-ig@w3.org>
** summary: The URI-reference from either an A in the footer or a LINK in the head leads you to a service (a retail service colloquially know as 'a page') which practices Device Independence per the DI Principles under development. This is either a universal HTML page after the manner of WCAG 1.0 with a [possibly un-mentioned, out-of-band] cross-index between legacy-compatible 'class' etc. marks in the page and the EARL model, or a polymorphic page after the manner of the Reef technology and CC/PP, or some other solution. But in any case the idea that "EARL is RDF" does not mean that the link from the "every page" context retrieves raw N3, for example. There is a [portal] 'report' page that consumerizes the information and gateways what is circulating in machine-friendly syntax through the EARL backoffice network into browser-friendly form for dispensing to generic and legacy [EARL unaware] clients. This is a server-side function by default [DI principle, according to PF, is any function can be done anywhere modulo bonafide dependencies being satisfied]. We should recognize separate pieces of the solution strategy: a) the "every page" technique for starting the path to metainformation and accessibility evaluation information in particular, and b) the "report page" techniques for representing reports of EARL information in broadly usable ways. This takes Device Independence techniques and client population sensitivity. c) what reporting services what users will want. This takes some market segmentation analysis. Some sites will only support canned reports, some will accept queries from downstream. This is a valuable application scenario for the DI, PF, Web Services and Global Grid Forum deliberations, by the way. [more details at foot] At 06:31 AM 2001-10-21 , Jim Ley wrote: >Nick Kew: >>Yes they do. <LINK> support is gradually hitting the mainstream (recent >>Mozilla and MSIE variants have finally got around to doing something >>sensible). You'll lose that by putting it in a <BODY>. > >MSIE??? If you mean my own suggestions of using various modifications to >IE, or is there some other support? If it's my techniques, then it doesn't >care about where they appear and serialises the DOM so it's still in >source position (so it suggests not error correction) I've not got the >latest Mozilla to test it's support > >>OTOH nothing in your example will be rendered by any existing browser - >>except the <LINK> if put in the <HEAD>. > >Or in the body? and I don't see how A can be used in any case as the EARL >report isn't human readable (well there's meaning, but it's not >accessible.) if it's audience is a machine, it does have to be hidden >from the user, but in a place where the user agents (of today, so we don't >need to wait until future UA's to use it.) and LINK in head does this, the >sub categorisation suggested by Al, also makes sense, as long as they >fallback to <LINK> > >This makes sense, it will degrade so is still useful to current user >agents: (I don't like DIV being in HEAD, and I don't see how having this >outside the HEAD is helpful.) > ><metadata> > <meta keywords="accessibility, report"> > <meta scheme="EARL 1.3.7"> > <link role="meta" href="URI-reference_returning_EARL_doc" > type="cturi:text/rdf;version=1.2"> ></metadata> > >(I need to see some justification of why we're breaking backwards >compatibility on the ROLE/REL issue with that.) > AG:: Thank you, Jim. This gives me a target I can shoot at. * Last point: 'role' vs. 'rel' -- I am treating them as synonymous, the particular token to be used to be determined by HTML WG. Anyone wants to write examples with 'rel' and I probably won't notice. What you are seeing here is just an artifact of my "design it in XML and migrate back to legacy compatible form" problem attack. [Sean's issues concerning 'role' deferred.] Mostly I am assuming that we could come up with some html:[link | a].rel or an xlink:role [or other property asserting structure in the reference-indicating expression] that authors could understand and new processors would recognize and old processors would safely ignore. * On the grouping in a 'metadata' element vs. a 'div' -- [again this is something where the details I am happy to defer to the HTML WG] I claim you should be no more happy with a 'metadata' collector than with a 'div' collector in the HEAD section. The 'div' is a pure structuring convention without taint of the purpose of the structuring. So it goes in the HEAD just fine. I am concerned that whatever internals we define to give properties to the enclosing container are defined in terms of "the enclosing container" and not "the 'metadata' element in which they are found." These functions are needed in multiple contexts. But in terms of designing the solution, all I meant was to suggest a collector element which will allow one to declare multiple concurrently-applicable properties in parallel syntactic substructures. A dedicated 'metadata' container would do the trick, but I was thinking DIV, as the generic scope creator, would be sufficient. This almost works except I realise that in doing so I have overloaded META which thus fails to communicate. HTML processors today think that META pertains to the whole document. Changing that would be a wrench. But the mission is there; the migration strategy is not clear yet. On the mission... * On why one wants meta decorations distributed through the body: I guess one reasonably approachable example has to do with orientation to page structure for navigation. Having keywords per major section of the page, and not just one title, would make it easier to write both a Table of Navigation extractor for the blind visitor using speech and the reading-difficulty visitor [not totally non-reading] using graphics. Doing differences on keywords is a good analysis technique from which to build a 'discovered' model of structure. It generates a machine-comprehensible statement of the logical flow of the story, even when the logic is not linear. You could generate a "The Brain" visualization of the intra-page structure from the keywords map. For the words-are-a-problem visitor, one could border the sections and decorate the borders with icons for the keywords. The terms that are selected as keywords are more likely than are words in general to have recognizable cliche images that work, and the tuples of icons would work to indicate differences and connections between sections in a way titles don't. Titles are ususally written assuming you grokked the super-title and they are written with that dependency so say what is different in this subsetion from the general topic of the supertitle. So topic-key tuples are about what you need to communicate to the hypo-lexic visitor. As John [...] says, "LD students are perpetually in a trial-and-error loop." You cannot assume that they carry the context over from a supercontainer, etc. Orientation which both distinguishes and connects is the order of the day. That is a motivational example. The general idea is that the associations should come from where they pertain, not indirectly through 'document' overhead. This is the argument about how the resource web is a) one connected infoset across many pages-as-served and b) a continuing structure containing sensible units at a finer grain than the page. This is presented in the attachments to my recent message dealing with "page scope not universal." See also the discussions from the HTML4 accessibility review under keyword REF. HTML4/CSS2 Accessibility Recommendations http://<http://www.w3.org/>www.w3.org/WAI/PF/report.html * about the user of html:a elements in a footer to form the connection. You have to understand that the question I am dealing with is "how does the recovery path for evaluation information that flows through the EARL system get launched in an 'every page' context?" Because I am in favor of something in every page [every XML and or web document that is detached and moved around separately] that starts a path to more information about the current instance that what is implied by the [inital a.k.a. base a.k.a. super-] type information that is sent ahead of the content. So I set aside the options that say "you trim the prefix to contain only the DNS domain and no path beyond that point and enquire of your 'information service' concerning how to get accessibility metadata dealing with that domain." So as soon as I am thinking about maximizing the legacy access to the information, I am not only thinking about using a vanilla hyperlink out of the page footer, but also how to serve the information from the URL that is in the HREF of that link. You have to remember that EARL is a model, not a syntax, in the first instance. So I have lots of options. I can do browser sniffing to set the server's initial CC/PP expectations of the client and still process CC/PP for CC/PP aware clients so the user has full control despite any assumptions that the server might initially make. This can be as simple as HTTP 1.1 transparent content negotiation or whatever CC/PP comes up with as something smarter. In any case, the server serving the URI-reference that comes out of the "plain vanilla hyperlink" may be serving a polymorphic resource which in certain cases is a plain HTML human-readable report of the evaluation results that are known, even down to formatting in an HTML emulation of the NCITS standard CIF format for these memos that comes out of the IUSR program at NIST. Where my heart is, on the other hand, is in interpretive-assistive overlays. This option has that link lead to a page which is _both_ legacy-friendly HTML _and_ EARL because it is the EARL model in HTML syntax with the model-syntax binding done in a way that is non-invasive with regard to the legacy processing of the HTML syntax. [Even this doesn't inhibit it much from being a CIF lookalike.] This is in the tradition of "literate programming" where programs are written in more or less "lab report" or "journal article" style and the compiler knows how to scan the code exhibits in the article and compile from the filtered output. Sean has working examples of this "RDF from HTML" path, from what I hear. I just want the binding declared in metadata and not just realised in an XSLT transformer. [Sorry to keep you all so long. Here is a picture that will make things a lot clearer.] What one gets to via the hyperlink from the footer is to some portal page that is a gateway to the EARL system. For purposes of concreteness, there is a slightly over-busy version of a four tier model of the distributed-computation universe at ftp://<ftp://ftp.evl.uic.edu/>ftp.evl.uic.edu/pub/OUTgoing/ACE/GCE-Overview. ppt This gives some context for what I am saying here. The problem of reporting the information in client-appropriate presentation details is worked in accordance with the evolution of Device Independence practices for the Web. The portal page is adaptive to the delivery context. The portal page is a report from the EARL system. On the server serving this portal page there is the report formatting function that delivers a variety of reports for downstream or legacy-client consumption. Information circulation within the EARL system is up to the EARL community to determine. The implementation of these portal pages is required to understand the schemas in which the backoffice bus of the EARL system is implemented. The EARL system is a [grid a.k.a. web] of interoperating services that log information, register that information with other information, collect an retain data reflecting the information, and query and report what information is available in the space of virtual data created. See Reagan Moore's output touting the push toward "virtual-data grids." The 'backoffice bus' common mode is the EARL _model_ expressed in RDF _model_-interoperable form. So what the portal page processor has to understand, and shields the client population from, is the polyglot world of RDF and its various bindings to syntax. And this last part, that the service serving the EARL information at the end of whatever link comes out of the "every page" context SHALL practice bestCurrentPractice DeviceIndependence practices is_a 'server-side WCAG 2" clause for any metadata required by WCAG. The reference from the "every page" context can come from an A in the footer or a LINK in the HEAD -- it doesn't matter which -- the service serving the HREFed URI-reference is responsible for the legibility and device- [including legacy-] independence of how the information is served to the public. That's the basic division of labor, here. Al >Jim. >
Received on Sunday, 21 October 2001 12:28:48 UTC