- From: David Poehlman <poehlman@clark.net>
- Date: Fri, 14 Aug 1998 10:20:32 -0400 (EDT)
- To: Napoleon Maou <maou@csi.forth.gr>
- cc: Jon Gunderson <jongund@staff.uiuc.edu>, w3c-wai-ua@w3.org
I still want a "go to specific link" capagility in there. if that link list is hundreds long and I want to go to 150, I don't want to have to perform repetitions of a next or previous or up arrow or down arrow. the method for accomplishing this would be to provide a dialog box when the "go to specified link" item is activated and you could type in a number if it was availabe or a string. otherwise, this is quite possibly an approach which solves much. On Fri, 14 Aug 1998, Napoleon Maou wrote: NMThank you for your comments. NM NMIn their current form, the guidelines refer to two mechanisms, which are NMused together to provide sequential navigation functionality within a view. NMThe first is described in section 6.1, "Sequential Navigation Within A View", NMand the second in section 7.2, "Menu Commands", Item 1. NM NMOur proposal combines the functionality of these two mechanisms, into one NMgeneric sequential navigation mechanism. We believe that the strongest points NMof the proposed approach lie with the simplicity and uniformity with which a NMuser will be able to navigate a document. Please note that this is independent NM NMof the actual types of elements that the user will be allowed to navigate by. NMThis way the user will have to perform fewer interaction steps to navigate NMamong elements of the same type, having, furthermore, only one set of NMnavigation NMcommands to memorize (compare this, for example, to having to remember NMdifferent NMkeyboard commands to move to the next heading, previous form element, etc.) NM NMLet us now move on to the issue of which elements should the user be allowed NMto navigate by. The term "any elements" used in the initial proposal, was not NMmeant to imply that navigation by *every* HTML elements should be possible. NMRather, it was meant to refer to those elements in the rendered page that the NMuser can distinguish from the rest, and identify as having particular NMcharacteristics. NMIn our view, the guidelines already assume that the user has a rather NMgood understanding of what a formatted text document is, as well as of the NMfunctional and non-functional attributes of elements that may be encountered NMwithin an HTML document. NM NMThe above is evident from the fact that the mechanism in section 6.1, allows NMthe user to sequentially visit links, form elements, images and image maps. A NMdirect implication of this is that the user knows what links, form elements, NMframes, images and image maps are. In the opposite case, a truly novice and NMinexperienced user will think that the browser arbitrarily scrolls to NMdifferent NMparts of the document. Furthermore, by proposing the use of menus for header NMnavigation, the guidelines assume that the user knows what a header is. This NMmeans that it is already assumed that the user comprehends at least part of NMthe NMdocument's formatting. NM NMBased on the above, the elements we believe the user should be at least NMallowed NMto navigate by are the following: links (including image map areas), elements NMwith NM"longdesc", forms and form elements, tables, lists and list items, elements NMwith NMDHTML events, paragraphs, sentences, headers. All these are elements that the NMuser NMcan distinguish from the rest of the elements in a page, and identify them as NMhaving NMa particular property / functionality. NM NMA second point you raised in your email concerns the employment of menus to NMprovide NMan overview of the document. Although it is a very good idea to allow the user NMto NMget different overviews of the document, menus might not be the best approach NMto NMpresenting them to the user. Menus excel when used to provide the user with an NM NMoverview of the functionality of an application and are rarely used when they NMare NMvery long, not to mention when they entirely different (with the exception of NMthe NMfirst few items) for every document the user visits. Imagine for example a NMmenu NMcontaining the headers of a long research publication with descriptive section NM NMheadings. The menu would be hardly usable. Or, what about a menu containing NMthe NMlinks in a "Links" page that is becoming a norm in almost all types of sites. NMPresenting a limited list of the elements in the menu, as specified in Section NM NM7.2, is a partial solution to the above problem, but introduces, in turn, a NMnew NMproblem, that of not allowing true "random" access to elements. If, for NMexample, NM10 headers are included in the list, and there are 15 in the document, then NMthe NMuser will not be able to directly access the last 5 ones, which compromises NMthe NMvery usefulness of the current approach. NM NMWe believe that a far more usable and elegant solution for providing document NMoverviews and enabling "random" access to document elements, would be the use NMof separate views, along with view synchronization, as specified in section NM4.7 "Alternative Views of the Document", Item 1. NM NMIn summary, we propose that the navigation mechanism for sequential access to NMdifferent types of document elements should be harmonized and, even better, NMunified across elements types. We further propose that overviews and "random" NMaccess to document elements are achieved through separate, synchronized views NMas already proposed by the guidelines, rather than through menus. NM NMTo better clarify the proposed approach I am including below the communication NM NMwith Bryan Campbell, in which specific examples of operation are included. NMComments and NMsuggestions are always more than welcome. NM NMBest regards, NM NMNapoleon NM NM NM NM+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ NM NM NMHello Bryan, NMAgain I would like to apologize for taking such a long time to reply to your NMmail. NM NMThanks for commenting on our proposal. NM NMThe number of keyboard commands the user needs to go through in order NMto use the navigation mechanism we propose depends on the specific NMchoices developers will make in implementing the mechanism. Instead NMof referring to key presses, therefore, please allow me to briefly NMdescribe the idea in terms of "interaction steps". Naturally, the NMideal implementation would manage to allocate single (combined) key NMpresses to each interaction steps. NM NMThe enhancement to the navigation model we are proposing involves NMtwo main tasks: (a) selection of the type of element (or elements, I NMwill explain this further below) by which the user will navigate the NMdocument, and (b) navigation within the document itself, including, NMbut not necessarily limited to, the ability to move to the next NMprevious elements of the selected type in the document, as well as NMthe ability to move to the very first and very last such elements in NMthe document. NM NMIn terms of functionality one can distinguish between two variations NMfor task one. If navigation is limited to a single type of element at NMany time (of course this does not include "normal" document navigation NMwhereby all elements are visited sequentially), then this is a task of NMsimply selecting an option among mutually exclusive alternatives. The NMnormative way of doing that would be through a menu (e.g. a menu NMentitled "Navigate" and items such as "By Header", "By Paragraph", NM"By Link", etc.) Very common, or frequently used options should of NMcourse have keyboard shortcuts, making them accessible in a single NMinteraction step, from any point in the interface. NM NMAn alternative to the above would be for the user to be allowed to NMselect multiple types of elements to be visited during navigation. NM NMOne way to implement this would be through the use of a dialog, which NMwould present the user with a list of navigational elements and allow NMhim/her to selecting multiple types of elements to navigate by. In NMthis case, the implementation of the navigational mechanism requires NMthe following interaction "steps" NM1) Open the dialog NM2) "Next" and "Previous" commands, to scroll through the list of NM items NM3) "Select" / "Unselect" command to add an element type to the NM current set of navigable elements NM3) An "OK" and a "Cancel" command to close the dialog NM NMThe "OK" and "Cancel" commands above would be the standard "OK" and NM"Cancel" keyboard commands used for all dialogs. The "Next" and NM"Previous" commands could be the same keyboard commands used to NMnavigate between elements in the view. NM NMAlthough this approach would significantly enhance the flexibility of NMthe navigation model, it would also be very demanding on the user, NMimposing considerable load on short and long term memory, both in terms NMof interaction, but also in terms of anticipated system behaviour (I could NMelaborate on this if necessary). Furthermore, we don't believe that the NMadded flexibility outweighs the resulting increased complexity. Therefore, NMwe would prefer that only the former approach be included in the NMguidelines. NM NMIn terms of interaction, the functionality of the second task (navigation NMin the document itself) can be implemented using four "commands": Go-To-Next- NMElement, Go-To-Previous-Element, Go-To-First-Element, and Go-To-Last-Element. NMOf the four, only the first two (next and previous element) are of vital NMimportance. The latter two (first and last element) would be invaluable NMthough in long documents, especially ones of a known structure. NM NMAttempting to address your question of how many keystrokes it would take to NMmake effective use of the proposed navigation model, I will go through a NMvery simple scenario (for the needs of the scenario I assumed that the NMfollowing correspondence between commands and keys exists: next element - NM"Arrow-Down", previous element - "Arrow-Up", last element - "End", first NMelement - "Home"): NM NMAssume you know that you want to select a link in a long document, but you NMare not sure if it was the third from the end, or the second from the end NM(note that the fact these is no other link between them does not imply that NMthese two are necessarily close to each other). Using the proposed approach NMyou would: NM1) press "Alt-L" to switch to link navigation mode (assuming that because NM it is a very important mode it has its own shortcut) NM2) press "End" to go to the last link in the document NM3) press "Arrow-Up" to go to the second link from the end, review the link NM and possibly NM4) press "Arrow-Up" again to go to the third link from the end NM NMI would like to iterate that the rationale for proposing this modification NMto the guidelines, is to ensure that the very good idea of supporting NMalternative navigation models (modes) in the document, is supported in an NMintuitive way, imposing as little interaction burden on the user as possible. NMIt is interesting to note that in most cases (I am tempted to say all but NMperhaps I am missing some complex cases, so I will refrain from that) the NMproposed approach is faster in terms of interaction steps and requires NMfewer keyboard shortcuts than the one currently included in the guidelines. NM NMWe would be very interested to find out what you and other people on the NMlist think, especially after the above, more detailed description. NM NMBest regards, NM NMNapoleon NM NM NMNapoleon Maou NMSoftware Engineer NMAT&HCI Laboratory NMICS-FORTH NMvoice : +3081391742 NMemail : maou@ics.forth.gr NMWWW : www.ics.forth.gr NM NM NM NM NMJon Gunderson wrote: NM NM> Your approach I think may work for an experienced user who understands NM> tags. But what about the niave user who won't know want to look for or NM> situations where a user just wants to get an overview of the document with NM> out having to read every element. NM> Jon NM> NM> At 09:17 PM 7/31/98 +0300, maou wrote: NM> >Hello, NM> >My name is Napoleon Maou and I am a staff member at the Assistive NM> >Technology and Human computer Interaction (AT&HCI) laboratory , at the NM> >Foundation of Research and Technology Hellas (FORTH). NM> > NM> >I am interested in technologies that will make the Web, or any other NM> >information system, accessible to people with disabilities. NM> >At FORTH I have participated in the development of the AVANTI unified NM> >browser, a browser that in addition to motor abled users, is accessible NM> >by blind and motor impaired users. NM> > NM> >I would like to comment on the subject of sequential navigation within a NM> >View. NM> > NM> >I believe that there should be only one generalized mechanism to NM> >navigate elements within a view. Section 6.1 talks about a mechanism for NM> >sequential navigation of links, form elements and elements with NM> >longdesc( using keyboard commands ) , and section 7.2 talks about NM> >another mechanism that can be used for sequential navigation of Headers NM> >or other elements ( using menus and menu shortcuts ). NM> > NM> >The problems I see with the existence of two mechanisms are the NM> >following NM> >1) There exist more than one keyboard commands or menu keyboard NM> >shortcuts, which have essentially the same meaning. "Move to next item". NM> >For example if we have menu items to navigate Headers and Paragraphs NM> >then there will be a "Next Header", a "Next Paragraph" and a "Next NM> >link/longdesc/form element" command. NM> >2) If the user wants to navigate Headers and paragraphs then the NM> >current mechanisms does not allow him to do that. He can navigate NM> >Headers or Paragraphs but not both at the same time. NM> >3) For people with motor disabilities using menus to navigate will be NM> >very time consuming. NM> >4) For blind people there is the problem of having to memorize more NM> >keyboard commands than are needed. NM> > NM> >Proposed Mechanism NM> >--------------------------- NM> >I believe that the UA should provide to the user a simple generalized NM> >mechanism to navigate any elements in the view. This mechanism should: NM> >a) Allow the user to select the elements he wants to navigate. NM> >b) Provide commands to move among the elements of the view. NM> > NM> >A mechanism like that I believe will be easy to use and is general NM> >enough to allow the user to navigate any element combinations. NM> > NM> >Napoleon Maou NM> > NM> >-- NM> >Napoleon Maou NM> >Software Engineer NM> >AT&HCI Laboratory NM> >ICS-FORTH NM> >voice : +3081391742 NM> >email : maou@ics.forth.gr NM> >WWW : www.ics.forth.gr NM> > NM> Jon Gunderson, Ph.D., ATP NM> Coordinator of Assistive Communication and Information Technology NM> Division of Rehabilitation - Education Services NM> University of Illinois at Urbana/Champaign NM> 1207 S. Oak Street NM> Champaign, IL 61820 NM> NM> Voice: 217-244-5870 NM> Fax: 217-333-0248 NM> E-mail: jongund@uiuc.edu NM> WWW: http://www.staff.uiuc.edu/~jongund NM> http://www.als.uiuc.edu/InfoTechAccess NM NM NM NM-- NMNapoleon Maou NMSoftware Engineer NMAT&HCI Laboratory NMICS-FORTH NMvoice : +3081391742 NMemail : maou@ics.forth.gr NMWWW : www.ics.forth.gr NM NM -- Hands-On-Technolog(eye)s touching the internet voice: 1-(301) 949-7599 poehlman@clark.net ftp://ftp.clark.net/pub/poehlman http://www.clark.net/pub/poehlman Dynamic solutions Inc. Best of service for your Small Business network Needs Http://www.dnsolutions.com
Received on Friday, 14 August 1998 10:22:49 UTC