- From: Al Gilman <asgilman@iamdigex.net>
- Date: Thu, 11 Jul 2002 10:36:42 -0400
- To: wai-xtech@w3.org
For planning purposes, here is a sketch of an authoring process and device-independent common-source resource web and adaptive tailored service framework that would seem to have enough in it to work for people with disabilities. There appears to be a candidate win plan for this problem. 1. The first form of the application that one designs is the Voice view. See http://lists.w3.org/Archives/Public/wai-xtech/2002Jul/0014.html for roughly why. It is mostly that the voice domain of interaction is something that the author understands which requires the simple step by step steps to be articulated. The author can understand "don't put too much on a page" more readily and sympathetically when they think in terms of a voice dialog. 2. The "foo should be in all contexts" rules (Exit, home, help, ...) from http://www.learningdisabilities.org.uk/html/content/webdesign.cfm are made a design constraint on the Voice dialog design, or at least on the interaction logic reference model. The voice binding can leave some of this out so long as it is defined in the interaction-logic references and can be pulled from there as needed. The higher level information architecture (structure and navigation) of the design still inherits design rules from the talking book model. Katie has been experimenting with this. If we have actual conflicts between what the digital book and severe learning difficulties models seem to require, we go back to design and experimentation to iterate on the model. But I claim that they are more alike than conflicting. [reconcile with research and standardization efforts on universal speech interface as well.] Summary: the definition of the abstract interaction logic of the application applies patterns from a reference model that has been cooked to be sufficient to ensure usability in a variety of different disability-driven [derived view] delivery contexts. With the macrostructure precedent of the digital talking book, the micro flow precedent of the severe learning difficulties web guidelines, and the media alternative precendents of images on the web and sound/action in multimedia we have the bulk of the rules now available. 3. Represent the interaction logic in the "controlled-appliance specification" model of the Personal Universal Controller project under Pittsburgh Pebbles at CMU. 4. Synthesize the chunking -- structure and flow -- of the frame sequence in a palm or desktop visual derivative through an industrial-strength extension of the algorithms that the PUC has developed for the Palmtop device class. But the logical complexity of the individual steps would be constrained by user requirements and not just device constraints. 5. Elaborate the rich media correlates of the interaction logic to fill the space available. Again where the computation of "space available" accounts for user preferences in addition to device capabilities. [advanced level: the combination of user preference for rich media plus the content-instance availability of rich media can actually drive the logical complexity per frame below that set by the constraints, in order to allow the "decorate to fill the space available" phase to have room for as much rich elaboration as the user prefers. The root method is global optimization under constraints, not just constraint satisfaction and local optimization.] The point here is that the severe learning difficulty consumer, using a desktop or TV sized display, would use the same chunking as the palmtop or cell phone consumer, with few words and lots of graphics consuming the pixels of the screen. But the few words that were there would be the same words (or synonyms recognizable by thesaurus) as compared with those one would use in a small-display device context such as voice or a WAP1 phone. [I am only developing the structure-and-flow aspect here. There is also a rich verisimilitude -- ususally called rich media -- aspect and a precise explanation aspect -- addressed in Lisa Seeman's draft schema at http://www.ubaccess.com/ils.html#drafts but I can't write the whole book at once...] The state of the art would seem to be that adaptive synthesis of the structure and flow of the dialog is beyond the capabilties of CSS but not beyond hope to get from the "single source authoring" tool suites developed by the Device Independence constituency. Particularly with the positive results coming out of CMU. The structure and flow would most likely be a server-side transform. The rich decoration of eye candy on the bones of a cell-phone-capable structure and flow could be a client-side matter. Or it could be done on the server side too. Certainly in the immersive (above desktop) client class it would be assembled on the client side or at a supernode portal very close in the network to the client node. The overall key fact is that we have separated some concerns: the step size of the dialog (complexity of the individual steps -- screens in the SLD whitepaper) from the degree of rich-media elaboration. The trendy language for how one separates the concerns is "aspect oriented programming." The point is that a given body of data or code does not address a single concern, but combines patterns inherited from multiple 'aspect'-distinguished ancestors. The standard web design would actually use less of the rich media relatives of the interaction logic because it was packing more interaction complexity on one screen and didn't have room for the full elaboration of the audiovisual re-enforcement. But "TV show mode" (SMIL multimedia presentation under "my preference is couch potato" conditions) would draw on all that audiovisual stuff and might only use the textual core in [normally hidden] subtitles and captions. Note that in we-try-harder mode an assistive user agent could use the "precise explanation" features to reach out onto the web to get more multimedia that relate to the interaction logic as defined by the author. Not all the rich media content would have to have been collected and offered by the originator of the core interaction logic. Some of that could come from general public knowledge or assistive-dedicated picture and sound thesaurus literature. Or the explanatory elaboration layers could come from the education market and not require development on a dedicated 'disability' basis. People with learning disabilities are less hung up over age stigma than are the children who are passing through acquisition of learning skills and knowledge very rapidly and are very sensitive to 'baby stuff' appropriate for stages that they feel they have passed. Al
Received on Thursday, 11 July 2002 10:37:53 UTC