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Contribution to Browser Accessibility Guidelines

From: Stephanidis Constantine <cs@csi.forth.gr>
Date: Thu, 19 Mar 1998 21:22:35 +0200 (EET)
Message-Id: <199803191922.VAA14578@ismene-lane.csi.forth.gr>
To: jongund@staff.uiuc.edu
Cc: cs@ics.forth.gr, JBrewer@w3.org, danield@w3.org, w3c-wai-ig@w3.org, w3c-wai-ua@w3.org

Dear Jon,

Please find attached in RTF and HTML format a document containing our 
contribution to the "World Wide Web Browser Guidelines". This document  is also 
available on-line at:


I look forward to seeing you in the WAI meeting on Saturday.

Best regards,


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{\operator AT & HCI Laboratory}{\creatim\yr1998\mo3\dy19\hr1\min2}{\revtim\yr1998\mo3\dy19\hr18\min7}{\printim\yr1998\mo3\dy19\hr17\min11}{\version3}{\edmins1}{\nofpages8}{\nofwords2624}{\nofchars14961}{\*\company ICS-FORTH}{\vern57431}}
\widowctrl\ftnbj\aenddoc\hyphcaps0 \fet0\sectd \linex0\headery709\footery709\colsx709 {\footer \pard\plain \s26\qj\nowidctlpar\tqc\tx4153\tqr\tx8306 \f4\lang2057 \tab Page {\field{\*\fldinst {\cs27  PAGE }}{\fldrslt {\cs27\lang1024 8}}}
\par }{\*\pnseclvl1\pnucrm\pnstart1\pnindent720\pnhang{\pntxta .}}{\*\pnseclvl2\pnucltr\pnstart1\pnindent720\pnhang{\pntxta .}}{\*\pnseclvl3\pndec\pnstart1\pnindent720\pnhang{\pntxta .}}{\*\pnseclvl4\pnlcltr\pnstart1\pnindent720\pnhang{\pntxta )}}{\*\pnseclvl5
\pndec\pnstart1\pnindent720\pnhang{\pntxtb (}{\pntxta )}}{\*\pnseclvl6\pnlcltr\pnstart1\pnindent720\pnhang{\pntxtb (}{\pntxta )}}{\*\pnseclvl7\pnlcrm\pnstart1\pnindent720\pnhang{\pntxtb (}{\pntxta )}}{\*\pnseclvl8\pnlcltr\pnstart1\pnindent720\pnhang
{\pntxtb (}{\pntxta )}}{\*\pnseclvl9\pnlcrm\pnstart1\pnindent720\pnhang{\pntxtb (}{\pntxta )}}\pard\plain \qc\nowidctlpar \f4\lang2057 {\b\fs36 Contribution to Accessibility Guidelines for 
\par World Wide Web Browsers
\par }
\par Constantine Stephanidis
\par {\fs20 Head, Assistive Technology and Human Computer Interaction Laboratory (AT&HCI Lab)
\par Institute of Computer Science (ICS), 
\par Foundation for Research and Technology - Hellas (FORTH)
\par Science and Technology Park of Crete, 
\par Heraklion, Crete, GR-71110, Greece
\par Tel: +30 81 391741, Fax: +30 81 391740, e-mail: cs@ics.forth.gr 
\par }
\par \pard \qj\nowidctlpar {\b\f5\fs28 Contents
\par }
\par \pard\plain \s15\fi-284\li284\nowidctlpar\tqr\tldot\tx8640 \f4\lang1024 {\field\fldedit{\*\fldinst  TOC \\o "1-2" }{\fldrslt 1. Introduction\tab {\field{\*\fldinst  GOTOBUTTON _Toc414965066  {\field{\*\fldinst  PAGEREF _Toc414965066 }{\fldrslt 1}}}}

\par 2. \ldblquote World Wide Web Browser Guidelines\rdblquote  Document\tab {\field{\*\fldinst  GOTOBUTTON _Toc414965067  {\field{\*\fldinst  PAGEREF _Toc414965067 }{\fldrslt 2}}}}
\par \pard\plain \s16\qj\li200\nowidctlpar\tqr\tldot\tx8640 \f4\lang2057 {\lang1024 A. Presentation Adjustment\tab }{\field{\*\fldinst {\lang1024  GOTOBUTTON _Toc414965068  }{\field{\*\fldinst {\lang1024  PAGEREF _Toc414965068 }}{\fldrslt {\lang1024 2}}}}}{
\par B. Navigation and Control\tab }{\field{\*\fldinst {\lang1024  GOTOBUTTON _Toc414965069  }{\field{\*\fldinst {\lang1024  PAGEREF _Toc414965069 }}{\fldrslt {\lang1024 3}}}}}{\lang1024 
\par C. Orientation\tab }{\field{\*\fldinst {\lang1024  GOTOBUTTON _Toc414965070  }{\field{\*\fldinst {\lang1024  PAGEREF _Toc414965070 }}{\fldrslt {\lang1024 5}}}}}{\lang1024 
\par }\pard\plain \s15\fi-284\li284\nowidctlpar\tqr\tldot\tx8640 \f4\lang1024 3. Miscellaneous Proposals\tab {\field{\*\fldinst  GOTOBUTTON _Toc414965071  {\field{\*\fldinst  PAGEREF _Toc414965071 }{\fldrslt 7}}}}
\par \pard\plain \s16\qj\li200\nowidctlpar\tqr\tldot\tx8640 \f4\lang2057 {\lang1024 Plug-ins\tab }{\field{\*\fldinst {\lang1024  GOTOBUTTON _Toc414965072  }{\field{\*\fldinst {\lang1024  PAGEREF _Toc414965072 }}{\fldrslt {\lang1024 7}}}}}{\lang1024 
\par HTML extensions and corresponding Browser features\tab }{\field{\*\fldinst {\lang1024  GOTOBUTTON _Toc414965073  }{\field{\*\fldinst {\lang1024  PAGEREF _Toc414965073 }}{\fldrslt {\lang1024 7}}}}}{\lang1024 
\par }\pard\plain \s15\fi-284\li284\nowidctlpar\tqr\tldot\tx8640 \f4\lang1024 4. \ldblquote Unified Web Site Accessibility Guidelines\rdblquote  Document (Version 8) - Guidelines for User Agents\tab {\field{\*\fldinst  GOTOBUTTON _Toc414965074  
{\field{\*\fldinst  PAGEREF _Toc414965074 }{\fldrslt 8}}}}
\par 5. Future Contributions\tab {\field{\*\fldinst  GOTOBUTTON _Toc414965075  {\field{\*\fldinst  PAGEREF _Toc414965075 }{\fldrslt 8}}}}
\par \pard\plain \qj\nowidctlpar \f4\lang2057 }}\pard\plain \qj\nowidctlpar \f4\lang2057 
\par \pard\plain \s1\sb240\sa60\keepn\nowidctlpar \b\f5\fs28\lang2057\kerning28 {\*\bkmkstart _Toc414965066}1. Introduction{\*\bkmkend _Toc414965066}
\par \pard\plain \qj\nowidctlpar \f4\lang2057 
\par This document is submitted in the context of the WAI User Agent working group, as a c
ontribution towards the development of the "WAI Accessibility User Agent Guidelines: Browser User Interface". It is, mainly, based on the document "World Wide Web Browser Guidelines" compiled by J. Gunderson (the version referred to as current, is the one
 updated on February 13, 1998). Included are: comments and suggestions for additions, or enhancements to existing categories of guidelines, and proposals for new guidelines (and possibly new sections). Some of the items (browser accessibility features and
 facilities) discussed in this document have already been implemented in the browser developed by ICS-FORTH, Greece, in the context of the ACTS AVANTI AC042 project funded by the European Commission. The AVANTI browser is a \ldblquote unified\rdblquote 
 browser that currently 
supports interaction by able-bodied, blind and motor-impaired individuals. ICS-FORTH will continue to work in this direction and is planning to be involved in the implementation of Web browsers that comply with the accessibility guidelines developed by th
e WAI User Agent working group.
\par \pard\plain \s1\sb240\sa60\keepn\nowidctlpar \b\f5\fs28\lang2057\kerning28 {\*\bkmkstart _Toc414965067}2. \ldblquote World Wide Web Browser Guidelines\rdblquote  Document{\*\bkmkend _Toc414965067}
\par \pard\plain \s2\qj\sb240\sa60\keepn\nowidctlpar \b\i\f5\lang2057 {\*\bkmkstart _Toc414965068}A. Presentation Adjustment{\*\bkmkend _Toc414965068}
\par \pard\plain \s3\qj\sb240\sa60\keepn\nowidctlpar \f5\lang2057 Override Font and Color Specification
\par \pard\plain \qj\nowidctlpar \f4\lang2057 {\b ADD}
\par {\pntext\pard\plain\f1\lang2057 \'b7\tab}\pard \qj\fi-360\li360\nowidctlpar{\*\pn \pnlvlblt\pnf1\pnindent360 {\pntxtb \'b7}}Users should be able to specify whether colors used {\i within}
 a page are to be used by the browser in rendering the document. These include, for example, colors for specific portions of text and colors used as background in table cells. These are additional to the standard colors used in rendering the document. In 
the case that users specify the background color 
for documents (or simply turn off the use of background images), but do not turn off the use of color inside the document, the browser should attempt to perform "clever" color substitution, so as to ensure that all text in a page is visible and has a sati
sfactory contrast with the page background.
\par \pard \qj\nowidctlpar 
\par \pard\plain \s3\qj\sb240\sa60\keepn\nowidctlpar \f5\lang2057 CSS Override and User Specification
\par \pard\plain \qj\nowidctlpar \f4\lang2057 {\b ADD}
\par {\pntext\pard\plain\f1\lang2057 \'b7\tab}\pard \qj\fi-360\li360\nowidctlpar{\*\pn \pnlvlblt\pnf1\pnindent360 {\pntxtb \'b7}}
Browsers should be able to support both visual and auditory style sheets (to support an auditory style-sheet, a browser would have to cooperate with a speech synthesis system). Users should then be given the possibility to specify both a visual and an aud
itory style-sheet to be used for rendering the document (the latter requires that browsers are able to render in visual and auditory modalities in parallel).
\par {\pntext\pard\plain\f1\lang2057 \'b7\tab}Experienced users should have the option of specifying {\i parts }of their personal style-sheet(s) which will always override the respective parts of style-sheets provided by document authors.
\par \pard \qj\nowidctlpar 
\par \pard\plain \s3\qj\sb240\sa60\keepn\nowidctlpar \f5\lang2057 Alternative Representations of Information
\par \pard\plain \qj\nowidctlpar \f4\lang2057 {\b ADD}
\par {\pntext\pard\plain\f1\lang2057 \'b7\tab}\pard \qj\fi-360\li360\nowidctlpar{\*\pn \pnlvlblt\pnf1\pnindent360 {\pntxtb \'b7}}
Provide enumeration for the different elements within the HTML page, for which alternative text is not provided, although such a possibility exists (e.g. through NAME, ALT or LONGDESC attributes in the respective tags).
\par \pard \qj\li720\nowidctlpar Example:
\par {\i Image map 1. Area 1. Area 2.} \'85
\par {\i Image 4.} Some other text. {\i Image 5.
\par }
\par \pard\plain \s3\qj\sb240\sa60\keepn\nowidctlpar \f5\lang2057 Alternative Views of Information
\par \pard\plain \qj\nowidctlpar \f4\lang2057 {\b ADD}
\par {\pntext\pard\plain\f1\lang2057 \'b7\tab}\pard \qj\fi-360\li360\nowidctlpar{\*\pn \pnlvlblt\pnf1\pnindent360 {\pntxtb \'b7}}Support text-only presentation mod
e (filtering out links, images, image maps, forms, tables, etc). This can facilitate blind users in reviewing a document, without becoming disoriented by presentation-specific information, multitudes of links, or structuring that has been used to achieve 
spatial arrangement of the elements in a page.
\par \pard \qj\nowidctlpar 
\par {\b ENHANCE}
\par {\pntext\pard\plain\f1\lang2057 \'b7\tab}\pard \qj\fi-360\li360\nowidctlpar{\*\pn \pnlvlblt\pnf1\pnindent360 {\pntxtb \'b7}}
In alternative, browser-generated views containing interactive elements of the HTML document, it should be possible for the user to use that view as a navigation aid. This could be achieved by allow
ing the user to move to the respective interaction element in the main document view, by selecting it in the "navigation" view. Alternatively, interactive elements included in navigation views should replicate the functionality of their main view counterp
arts and should retain state when users switch between views.
\par \pard\plain \s3\qj\sb240\sa60\keepn\nowidctlpar \f5\lang2057 Browser Menus and Dialog Boxes
\par \pard\plain \qj\nowidctlpar \f4\lang2057 
\par No comments.{\b 
\par }\pard\plain \s2\qj\sb240\sa60\keepn\nowidctlpar \b\i\f5\lang2057 {\*\bkmkstart _Toc414965069}B. Navigation and Control{\*\bkmkend _Toc414965069}
\par \pard\plain \qj\nowidctlpar \f4\lang2057 
\par {\i Preliminary ideas concerning user events which trigger scripts within a document and how disabled people make use of them.
 Bellow are the main questions which appear in the current version of the guidelines document followed by our corresponding proposals.
\par }
\par {\b How will the person know the event exists?
\par }The browser can notify the user of the existence of events handled by scripts in a document in two different ways:
\par {\pntext\pard\plain\f1\lang2057 \'b7\tab}\pard \qj\fi-360\li360\nowidctlpar{\*\pn \pnlvlblt\pnf1\pnindent360 {\pntxtb \'b7}}
From any point within a document, the user requests that a list of all events handled in the document be presented to him/her. The browser responds by presenting the user with a list, containing each individual even
t, along with its associated element. Example entries in that list might be: "Move the mouse cursor over the link with text: What's new", "Press the button with label: Fill in default fields".
\par {\pntext\pard\plain\f1\lang2057 \'b7\tab}
While presenting an element with associated events to the user, the browser could either "attach" to the presentation a list containing these events, or, alternatively, could demarcate the element as having events associated with it. In the second case, u
sers should be able to request that a list containing the even
ts associated with the demarcated element be presented to them. The list would be identical to the one in the first case and example entries in it might include: "Move the mouse over the link", "Press the button".
\par \pard \qj\nowidctlpar 
Please note above, that the difference between the entries in the "global" event list and the one local to an element, is that entries in the first also include some information regarding the element with which they are associated, that is redundant infor
mation in the local list.
\par {\b How can events be emulated, or simulated?
\par }
The user should be able to "trigger" any event corresponding to an entry in the lists described in the previous question, by selecting / activating that entry. All of the user (interaction) events that are used in browsers today, or are foreseen as extens
ions to be supported in the near future can be very easily replicated by browsers.
\par {\b How do users know how the event changed the document?
\par }The browser should be able to report all the modifications that a script makes to the current
 state of a document being viewed by the user. This includes for example transition to an entirely new HTML document, transition to a new document within a frame, substitution of an image, etc. This type of report should be automatically provided to the u
ser following the activation of an event, as described in the previous two questions. Furthermore, the user should be given the option of "undoing" the event, i.e. returning to the state of the document, or interaction, that was valid prior to its activat
n. This option should be made available to the user starting with the activation of an event and should be explicitly, or implicitly declined by the user, after all modifications made have been presented, and before interaction with the document may comme
nce again.
\par \pard\plain \s3\qj\sb240\sa60\keepn\nowidctlpar \f5\lang2057 Navigation Commands with Mouse Equivalents
\par \pard\plain \qj\nowidctlpar \f4\lang2057 {\b ADD}
\par {\pntext\pard\plain\f1\lang2057 \'b7\tab}\pard \qj\fi-360\li360\nowidctlpar{\*\pn \pnlvlblt\pnf1\pnindent360 {\pntxtb \'b7}}Support alternative intra-page navigation facilities. For example n
on-visual navigation facilities for blind and functionally blind users may concern quick access to, and navigation through, different page elements using keyboard commands with auditory feedback e.g. transition from paragraph to paragraph, link to link, i
mage to image, sentence to sentence, etc.
\par \pard \qj\nowidctlpar {\b CLARIFY}
\par {\pntext\pard\plain\f1\lang2057 \'b7\tab}\pard \qj\fi-360\li360\nowidctlpar{\*\pn \pnlvlblt\pnf1\pnindent360 {\pntxtb \'b7}}
It should be clarified that the "list-of-all-links" functionality (i.e. providing the user with a list of the links included in the document, in a separate dialog element) included in the existing version
 of the guidelines, concerns image-map areas, in addition to links specified using the Anchor tag.
\par \pard\plain \s3\qj\sb240\sa60\keepn\nowidctlpar \f5\lang2057 List of Important Navigation Commands
\par \pard\plain \qj\nowidctlpar \f4\lang2057 {\b ADD}
\par {\pntext\pard\plain\f1\lang2057 \'b7\tab}\pard \qj\fi-360\li360\nowidctlpar{\*\pn \pnlvlblt\pnf1\pnindent360 {\pntxtb \'b7}}In addition to {\i links-, headers-, list items-, forms-, tables-, frames- }and{\i  DHTML-}
 based navigation commands (e.g. move to previous, next element), {\b\i sentence}{\i , }{\b\i paragraph} and {\b\i image map}
 based navigation commands should be supported. The first two would be of great use to blind users. The third is of more general use, as image-maps are often used as navigation, or option "menus".
\par \pard \qj\nowidctlpar 
\par {\b There are no comments regarding the rest of the existing sections under }{\b\i Navigation and Control}{\b .
\par }
\par \pard\plain \s3\qj\sb240\sa60\keepn\nowidctlpar \f5\lang2057 {\i New proposal}: Assist the user in navigating between pages
\par \pard\plain \qj\nowidctlpar \f4\lang2057 
\par Provide {\b inter-page navigation }
facilities. Such facilities may concern memory aids for blind people, non-linear history presentation, alternative presentation of bookmarks, enhanced feedback for visited pages or pages in the bookmarks, ageing of pages, etc. Some of these facilities (al
ong with others proposed outside the scope of rendering browsers accessible) would benefit disabled and able-bodied users alike, as they would significantly increase the usability of a browser.
\par \pard\plain \s2\qj\sb240\sa60\keepn\nowidctlpar \b\i\f5\lang2057 {\*\bkmkstart _Toc414965070}C. Orientation{\*\bkmkend _Toc414965070}
\par \pard\plain \qj\nowidctlpar \f4\lang2057 
\par {\i Preliminary ideas concerning the provision of orientation support to the user. Bellow are the main questions which appear in the current version of the guidelines document, followed by our corresponding proposals.
\par }
\par {\b How does the user know how large a document is?
\par }Size is a difficult issue, as different users perceive size in different ways. For example, the n
umber of lines could be an indication of the size of the document, but this would require that a standard algorithm be used to calculate lines (e.g. 80 "visible", i.e. non-tag, characters constitute a line). Alternatively, the number of sentences in the d
ocument could be used. The file size of a document could also be used, but it would only provide a rough estimate of the relative size of the document: an HTML page might be 6 Kbytes, for example, out of which only 1 Kbyte results in "real" information th
at gets presented to the user (while the rest is made up of tags, etc).
\par For blind, or visually-impaired users, an appropriate representation for approximate document size should be established. For example, the browser could allow the user to define what in his / her opinion constitutes a "small", "medium", or "large" documen
t (e.g. in terms of lines, or sentences). The browser would then use one of the three alternatives to characterise a document. 
\par {\b How does the user know about the content of the page (headers, tables, frames, links, etc.)?
\par }A good solution for a brief overview of the contents of the page appears in the current version of the guidelines under the section {\i Document Summary Information}
. An alternative type of content overview is also discussed in the same document, under the section {\i Document Structural Information}
. Please also refer to the corresponding section of this document for a proposal to enhance the latter type of overview.
\par {\b How does the user know / find the major topics of the page? 
\par }Un
less the major topics of a page appear in headings, it is practically impossible for the browser to locate them (for example, semantic analysis of the contents of the page would be required). Along these lines, the issue of supporting the user in identify
ing the major topics of a page is equivalent to presenting the user with a high-level view of the document contents and providing associated navigation facilities (see previous sections).
\par {\b Where is the user in the document?
\par }This question pertains mainly to 
visually-impaired users, since sighted users have the benefit of the proportional scrollbar thumb, which is now standard on all major platforms. A possible solution for visually-impaired users would be to associate the position of the user in a document w
ith the "amount" of the document that has already been presented to them. For example, indicating to a user that s/he is one third of the way through a document, indicates that there is roughly twice as much information in the document as they have alread
y "viewed". This idea would be of value even when users moved through the document without reading it.
\par \pard\plain \s3\qj\sb240\sa60\keepn\nowidctlpar \f5\lang2057 {\i New Proposal}: Container Element Summary
\par \pard\plain \qj\nowidctlpar \f4\lang2057 
\par In addition to providing orientation information to the user concerning the document in its entirety, it is important to extend orientation support \ldblquote within\rdblquote 
 the document, i.e. assist users while they are reviewing an HTML page. This type of support could also have the form a brief summary, which, unlike its \ldblquote global\rdblquote  counterpart would concern individual \ldblquote composite\rdblquote  el
ements. The term \ldblquote composite\rdblquote 
 is used to refer to elements that are made up of more than one simpler items. Such elements include lists, image-maps, tables, forms, etc. Indicative types of summaries that could be provided by the browser in each case are: l
ist with x list items; image-map with x links; table with x rows and y columns; form with x elements; etc. The summary could be more detailed than in the examples above, depending on the expertise, or preferences of the user (e.g. form with x edit fields,
 y radio buttons, a Submit button and a Reset button). Users with print impairments would greatly benefit from such a feature, as they would always have an idea of what they can expect next.
\par \pard\plain \s3\qj\sb240\sa60\keepn\nowidctlpar \f5\lang2057 Document Structural Overview
\par \pard\plain \qj\nowidctlpar \f4\lang2057 {\b ENHANCE
\par {\pntext\pard\plain\f1\lang2057 \'b7\tab}}\pard \qj\fi-283\li283\nowidctlpar{\*\pn \pnlvlblt\pnf1\pnstart1\pnindent283\pnhang{\pntxtb \'b7}}Provide a {\b structured overview }
of the page by constructing a hierarchical representation of the main elements (e.g. headings, image-maps, images, tables, sections, paragraphs, forms) in the HTML page. This representation should preserve information about the \ldblquote nesting
\rdblquote  of elements (e.g. a form appears within the section demarcated by a level 2 heading, area links are grouped within an image-map, etc.), as well as the order in which elements appear in the document. 
\par {\pntext\tab}\pard \qj\nowidctlpar{\*\pn \pnlvlcont\pnf1\pnstart1\pnindent283\pnhang{\pntxtb \'b7}}
\par \pard \qj\li284\nowidctlpar 
A possible visual representation that could be used for the type of overview described above would be a hierarchical tree control. Blind users should also have access to the hierarchical structure in a slightly different manner: It is difficult to conceiv
e multiple levels of a hierarchy when presented sequentially (which would be the case if items at different levels in the hierarchy were presented \ldblquote at the same time\rdblquote ). A method usually employed to overcome this problem, is to 
\ldblquote render\rdblquote  levels separately, i.e. the user is presented with one level of the hierarchy at a time; when a non-leaf item at that level is selected, the hierarchy is descended and the subordinate, \ldblquote lower\rdblquote 
 level is presented; the user may continue down the hierarchy, or return to the previous level.
\par {\pntext\tab}\pard \qj\nowidctlpar{\*\pn \pnlvlcont\pnf1\pnstart1\pnindent283\pnhang{\pntxtb \'b7}}
\par \pard \qj\li284\nowidctlpar The proposed structured overview of a document would complement the \ldblquote flat\rdblquote 
 overviews already suggested in the guidelines and in this document, and would allow experienced users to get a quick idea of both the type content in the page and the way in which 
it has been structured, which is more than often valuable information in itself.
\par \pard \qj\nowidctlpar 
\par {\b There are no comments regarding the rest of the existing sections under }{\b\i Orientation}{\b .
\par }
\par \pard\plain \s1\sb240\sa60\keepn\nowidctlpar \b\f5\fs28\lang2057\kerning28 {\lang1024 {\*\bkmkstart _Toc414965071}3. Miscellaneous Proposals{\*\bkmkend _Toc414965071}
\par }\pard\plain \qj\nowidctlpar \f4\lang2057 
\par This section contains proposals that could not be categorised under the existing sections of the current document.
\par \pard\plain \s2\qj\sb240\sa60\keepn\nowidctlpar \b\i\f5\lang2057 {\*\bkmkstart _Toc414965072}Plug-ins{\*\bkmkend _Toc414965072}
\par \pard\plain \s3\qj\sb240\sa60\keepn\nowidctlpar \f5\lang2057 Style sheets
\par \pard\plain \qj\nowidctlpar \f4\lang2057 
\par Browsers should support the incorporation of plug-ins that render information in alternative modalities than the ones directly supported by the browser. In parallel, they should allow for respective style-sheets to be associated and used with those plug-i
ns. For example, a plug-in that renders text in Braille could be associated with a "tactile" style-sheet. The ability of the browser to render information in multiple modalities in parallel should be preserved when such plug-ins are added.
\par \pard\plain \s3\qj\sb240\sa60\keepn\nowidctlpar \f5\lang2057 Navigation
\par \pard\plain \qj\nowidctlpar \f4\lang2057 
\par The browser should be able to relay events from plug-ins to the user. It should also allow the user to manipulate the state of plug-ins, to whatever extend possible. As an absolute minimum, the user should be notified of the activation of a plug-in, the t
ype of content (a textual description, if available, otherwise the content identifier) handled by the plug-in, and should be allowed to start, stop and pause the execution of the plug-in.
\par \pard\plain \s2\qj\sb240\sa60\keepn\nowidctlpar \b\i\f5\lang2057 {\*\bkmkstart _Toc414965073}HTML extensions and corresponding Browser features{\*\bkmkend _Toc414965073}
\par \pard\plain \s3\qj\sb240\sa60\keepn\nowidctlpar \f5\lang2057 Alternative representation of elements
\par \pard\plain \qj\nowidctlpar \f4\lang2057 
\par An attribute should be introduced in elements that support alternative textual descriptions, through which page authors could specify a sound to be used for the alternative representation of an element in auditory form (e.g. 'ALTSOUND').
\par \pard\plain \s1\fi-284\li284\sb240\sa60\keepn\nowidctlpar \b\f5\fs28\lang2057\kerning28 {\*\bkmkstart _Toc414965074}4. \ldblquote Unified Web Site Accessibility Guidelines\rdblquote  Document (Version 8) - Guidelines for User Agents
{\*\bkmkend _Toc414965074} 
\par \pard\plain \qj\nowidctlpar \f4\lang2057 {\b\fs28 
\par }The guidelines addressing user agent accessibility that appear in the {\i Unified Web Site Accessibility Guidelines} document and are not already part of the document for {\i World Wide Web Browser Guidelines}
 should be incorporated and categorised accordingly (currently they are categorised by HTML tag).
\par {\lang1024 
\par }\pard\plain \s1\sb240\sa60\keepn\nowidctlpar \b\f5\fs28\lang2057\kerning28 {\*\bkmkstart _Toc414965075}5. Future Contributions{\*\bkmkend _Toc414965075}
\par \pard\plain \qj\nowidctlpar \f4\lang2057 
\par Future contributions from ICS-FORTH, Greece, will be in the direction of guidelines that will address the development of Web Browsers that follow the concept of \ldblquote direct\rdblquote 
 accessibility. This concept advocates the incorporation of accessibility facilities
 within the browser application, reducing (and ultimately eliminating) the need for third-party accessibility software (in the sense that it will become an inherent part of the application itself).
\par }

Received on Thursday, 19 March 1998 14:23:03 UTC

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