Re: Techniques for 3.1 (get alternative content)

Hello,

It seems to me that ATAG Checkpoint 3.1 refers only to WCAG Guideline 1
(Checkpoints 1.1-1.5).

Since WCAG Checkpoints 1.1-1.4 are all priority 1, the only reason ATAG
Checkpoint 3.1 is Relative Priority is that WCAG Checkpoint 1.5 (provide
redundant text links for client side image maps) is Priority 3.

Therefore it would be straightforward to list the priority 1 and
priority 3 items from the WCAG guidelines.

However, they are already listed in the WCAG guidelines!  After some
reflection, it seems to me that the techniques for ATAG should focus on
ways that tools can meet our guidelines most effectively.  Such as
pointing out how multiple guidelines can be met simultaneously, to what
extent certain things can be automated, etc..

For example, for 3.1, we could say something like:

"In order to comply with 3.1 to Priority 1, the authoring tool must
ensure that the author is prompted to provide alternative content for
all the specific elements and general classes of elements listed in WCAG
1.1-1.4.  To comply to Priority 3, WCAG 1.5 must also be implemented."

We could then go on to discuss how 




Charles McCathieNevile wrote:
> 
> Comments please? Would it be helpful to have these online somewhere?
> 
> techniques for atag 3.1 "Prompt the author to provide equivalent alternatiive
> information"
> 
> Charles McCN
> 
>   WCAG Checkpoints:
> 
>    1.1 Provide a text equivalent for every non-text element (e.g., via
>           "alt", "longdesc", or in element content). This includes:
>           images, graphical representations of text (including symbols),
>           image map regions, animations (e.g., animated GIFs), applets
>           and programmatic objects, ascii art, frames, scripts, images
>           used as list bullets, spacers, graphical buttons, sounds
>           (played with or without user interaction), stand-alone audio
>           files, audio tracks of video, and video. [Priority 1]
>           For example, in HTML:
> 
>           + Use "alt" for the IMG, INPUT, and APPLET elements, or provide
>             a text equivalent in the content of the OBJECT and APPLET
>             elements.
>           + For complex content (e.g., a chart) where the "alt" text does
>             not provide a complete text equivalent, provide an additional
>             description using, for example, "longdesc" with IMG or FRAME,
>             a link inside an OBJECT element, or a [1]description link.
>           + For image maps, either use the "alt" attribute with AREA, or
>             use the MAP element with A elements (and other text) as
>             content.
> 
>           Refer also to [2]checkpoint 9.1 and [3]checkpoint 13.10.
> 
>           [4]Techniques for checkpoint 1.1
> 
>         HTML
> 
>                o prompt for longdesc and alt for img elements
>                o prompt for alt for area elements
>                o prompt for text transcript for audio objects.
>                o prompt for collated text transcript for movies.
> 
>         SVG
>                 Prompt for a title and desc for each g group
> 
>         SMIL
>                 Prompt for alt, longdesc, a text or textstream object for
>                 audio, image and video objects
> 
>    1.2 Provide redundant text links for each active region of a
>           server-side image map. [Priority 1]
>           Refer also to [5]checkpoint 1.5 and [6]checkpoint 9.1.
>           [7]Techniques for checkpoint 1.2
> 
>    1.3 [8]Until user agents can automatically read aloud the text
>           equivalent of a visual track, provide an auditory description
>           of the important information of the visual track of a
>           multimedia presentation. [Priority 1]
>           Synchronize the [9]auditory description with the audio track as
>           per [10]checkpoint 1.4. Refer to [11]checkpoint 1.1 for
>           information about textual equivalents for visual information.
>           [12]Techniques for checkpoint 1.3
> 
>    1.4 For any time-based multimedia presentation (e.g., a movie or
>           animation), synchronize equivalent alternatives (e.g., captions
>           or auditory descriptions of the visual track) with the
>           presentation. [Priority 1]
>           [13]Techniques for checkpoint 1.4
> 
>    1.5 [14]Until user agents render text equivalents for client-side
>           image map links, provide redundant text links for each active
>           region of a client-side image map. [Priority 3]
>           Refer also to [15]checkpoint 1.2 and [16]checkpoint 9.1.
>           [17]Techniques for checkpoint 1.5
> 
>         HTML
>                 Use the alt associated with area elements to build a
>                 redundant text navigation bar
> 
>    2.1 Ensure that all information conveyed with color is also available
>           without color, for example from context or markup. [Priority 1]
>           [18]Techniques for checkpoint 2.1
> 
>    2.2 Ensure that foreground and background color combinations provide
>           sufficient contrast when viewed by someone having color
>           deficits or when viewed on a black and white screen.
>           [Priority 2 for images, Priority 3 for text].
>           [19]Techniques for checkpoint 2.2
> 
>         HTML
>                 Where only one color has been specified (for example a
>                 background but not foreground) ask the author to confirm
>                 or specify colors for other parts, where possible from a
>                 range that has sufficient contrast
> 
>    3.1 When an appropriate markup language exists, use markup rather than
>           images to convey information. [Priority 2]
>           For example, use MathML to mark up mathematical equations, and
>           [20]style sheets to format text and control layout. Also, avoid
>           using images to represent text -- use text and style sheets
>           instead. Refer also to [21]guideline 6 and [22]guideline 11.
>           [23]Techniques for checkpoint 3.1
> 
>    3.2 Create documents that validate to published formal grammars.
>           [Priority 2]
>           For example, include a document type declaration at the
>           beginning of a document that refers to a published DTD (e.g.,
>           the strict HTML 4.0 DTD).
>           [24]Techniques for checkpoint 3.2
> 
>    3.3 Use style sheets to control layout and presentation. [Priority 2]
>           For example, use the CSS 'font' property instead of the HTML
>           FONT element to control font styles.
>           [25]Techniques for checkpoint 3.3
> 
>    3.4 Use relative rather than absolute units in markup language
>           attribute values and style sheet property values. [Priority 2]
>           For example, in CSS, use 'em' or percentage lengths rather than
>           'pt' or 'cm', which are absolute units. If absolute units are
>           used, validate that the rendered content is usable (refer to
>           the [26]section on validation).
>           [27]Techniques for checkpoint 3.4
> 
>    3.5 Use header elements to convey document structure and use them
>           according to specification. [Priority 2]
>           For example, in HTML, use H2 to indicate a subsection of H1. Do
>           not use headers for font effects.
>           [28]Techniques for checkpoint 3.5
> 
>    3.6 Mark up lists and list items properly. [Priority 2]
>           For example, in HTML, nest OL, UL, and DL lists properly.
>           [29]Techniques for checkpoint 3.6
> 
>    3.7 Mark up quotations. Do not use quotation markup for formatting
>           effects such as indentation. [Priority 2]
>           For example, in HTML, use the Q and BLOCKQUOTE elements to
>           markup short and longer quotations, respectively.
>           [30]Techniques for checkpoint 3.7
> 
>    4.1 Clearly identify changes in the natural language of a document's
>           text and any [31]text equivalents (e.g., captions).
>           [Priority 1]
>           For example, in HTML use the "lang" attribute. In XML, use
>           "xml:lang".
>           [32]Techniques for checkpoint 4.1
> 
>    4.2 Specify the expansion of each abbreviation or acronym in a
>           document where it first occurs. [Priority 3]
>           For example, in HTML, use the "title" attribute of the ABBR and
>           ACRONYM elements. Providing the expansion in the main body of
>           the document also helps document usability.
>           [33]Techniques for checkpoint 4.2
> 
>    4.3 Identify the primary natural language of a document. [Priority 3]
>           For example, in HTML set the "lang" attribute on the HTML
>           element. In XML, use "xml:lang". Server operators should
>           configure servers to take advantage of HTTP content negotiation
>           mechanisms ([34][RFC2068], section 14.13) so that clients can
>           automatically retrieve documents of the preferred language.
>           [35]Techniques for checkpoint 4.3
> 
>    5.1 For data tables, identify row and column headers. [Priority 1]
>           For example, in HTML, use TD to identify data cells and TH to
>           identify headers.
>           [36]Techniques for checkpoint 5.1
> 
>    5.2 For data tables that have two or more logical levels of row or
>           column headers, use markup to associate data cells and header
>           cells. [Priority 1]
>           For example, in HTML, use THEAD, TFOOT, and TBODY to group
>           rows, COL and COLGROUP to group columns, and the "axis",
>           "scope", and "headers" attributes, to describe more complex
>           relationships among data.
>           [37]Techniques for checkpoint 5.2
> 
>    5.3 Do not use tables for layout unless the table makes sense when
>           linearized. Otherwise, if the table does not make sense,
>           provide an alternative equivalent (which may be a
>           [38]linearized version). [Priority 2]
>           Note. [39]Once user agents support style sheet positioning,
>           tables should not be used for layout. [40]Refer also to
>           checkpoint 3.3.
>           [41]Techniques for checkpoint 5.3
> 
>    5.4 If a table is used for layout, do not use any structural markup
>           for the purpose of visual formatting. [Priority 2]
>           For example, in HTML do not use the TH element to cause the
>           content of a (non-table header) cell to be displayed centered
>           and in bold.
>           [42]Techniques for checkpoint 5.4
> 
>    5.5 Provide summaries for tables. [Priority 3]
>           For example, in HTML, use the "summary" attribute of the TABLE
>           element.
>           [43]Techniques for checkpoint 5.5
> 
>    5.6 Provide abbreviations for header labels. [Priority 3]
>           For example, in HTML, use the "abbr" attribute on the TH
>           element.
>           [44]Techniques for checkpoint 5.6
> 
>    6.1 Organize documents so they may be read without style sheets. For
>           example, when an HTML document is rendered without associated
>           style sheets, it must still be possible to read the document.
>           [Priority 1]
>           When content is organized logically, it will be rendered in a
>           meaningful order when style sheets are turned off or not
>           supported.
>           [45]Techniques for checkpoint 6.1
> 
>    6.2 Ensure that equivalents for dynamic content are updated when the
>           dynamic content changes. [Priority 1]
>           [46]Techniques for checkpoint 6.2
> 
>    6.3 Ensure that pages are usable when scripts, applets, or other
>           programmatic objects are turned off or not supported. If this
>           is not possible, provide equivalent information on an
>           alternative accessible page. [Priority 1]
>           For example, ensure that links that trigger scripts work when
>           scripts are turned off or not supported (e.g., do not use
>           "javascript:" as the link target). If it is not possible to
>           make the page usable without scripts, provide a text equivalent
>           with the NOSCRIPT element, or use a server-side script instead
>           of a client-side script, or provide an alternative accessible
>           page as per [47]checkpoint 11.4. [48]Refer also to guideline 1.
>           [49]Techniques for checkpoint 6.3
> 
>         HTML
>                 Ask for equivalents for scripts, and applets, for example
>                 a movie (and collated text transcripts, audio, etc)
> 
>    6.4 For scripts and applets, ensure that event handlers are input
>           device-independent. [Priority 2]
>           Refer to the definition of [50]device independence.
>           [51]Techniques for checkpoint 6.4
> 
>    6.5 Ensure that dynamic content is accessible or provide an
>           alternative presentation or page. [Priority 2]
>           For example, in HTML, use NOFRAMES at the end of each frameset.
>           For some applications, server-side scripts may be more
>           accessible than client-side scripts.
>           [52]Techniques for checkpoint 6.5
> 
>    7.1 [53]Until user agents allow users to control flickering, avoid
>           causing the screen to flicker. [Priority 1]
>           Note. People with photosensitive epilepsy can have seizures
>           triggered by flickering or flashing in the 4 to 59 flashes per
>           second (Hertz) range with a peak sensitivity at 20 flashes per
>           second as well as quick changes from dark to light (like strobe
>           lights).
>           [54]Techniques for checkpoint 7.1
> 
>         HTML (relying on lowsrc attribute - not in W3C recommendation)
>                 Prompt for a non-animated "lowsrc" version of animated
>                 images.
> 
>    7.2 [55]Until user agents allow users to control blinking, avoid
>           causing content to blink (i.e., change presentation at a
>           regular rate, such as turning on and off). [Priority 2]
>           [56]Techniques for checkpoint 7.2
> 
>    7.3 [57]Until user agents allow users to freeze moving content, avoid
>           movement in pages. [Priority 2]
>           When a page includes moving content, provide a mechanism within
>           a script or applet to allow users to freeze motion or updates.
>           Using style sheets with scripting to create movement allows
>           users to turn off or override the effect more easily. [58]Refer
>           also to guideline 8.
>           [59]Techniques for checkpoint 7.3
> 
>    7.4 [60]Until user agents provide the ability to stop the refresh, do
>           not create periodically auto-refreshing pages. [Priority 2]
>           For example, in HTML, don't cause pages to auto-refresh with
>           "HTTP-EQUIV=refresh" until user agents allow users to turn off
>           the feature.
>           [61]Techniques for checkpoint 7.4
> 
>    7.5 [62]Until user agents provide the ability to stop auto-redirect,
>           do not use markup to redirect pages automatically. Instead,
>           configure the server to perform redirects. [Priority 2]
>           [63]Techniques for checkpoint 7.5
> 
>    8.1 Make programmatic elements such as scripts and applets directly
>           accessible or compatible with assistive technologies
>           [Priority 1 if functionality is [64]important and not presented
>           elsewhere, otherwise Priority 2.]
>           [65]Refer also to guideline 6.
>           [66]Techniques for checkpoint 8.1
> 
>    9.1 Provide client-side image maps instead of server-side image maps
>           except where the regions cannot be defined with an available
>           geometric shape. [Priority 1]
>           Refer also to [67]checkpoint 1.1, [68]checkpoint 1.2, and
>           [69]checkpoint 1.5.
>           [70]Techniques for checkpoint 9.1
> 
>         HTML
>                 Use the same interface for defining areas, and produce
>                 the image as client-side where possible
> 
>    9.2 Ensure that any element that has its own interface can be operated
>           in a device-independent manner. [Priority 2]
>           Refer to the definition of [71]device independence.
>           [72]Refer also to guideline 8.
>           [73]Techniques for checkpoint 9.2
> 
>    9.3 For scripts, specify logical event handlers rather than
>           device-dependent event handlers. [Priority 2]
>           [74]Techniques for checkpoint 9.3
> 
>    9.4 Create a logical tab order through links, form controls, and
>           objects. [Priority 3]
>           For example, in HTML, specify tab order via the "tabindex"
>           attribute or ensure a logical page design.
>           [75]Techniques for checkpoint 9.4
> 
>    9.5 Provide keyboard shortcuts to important links (including those in
>           [76]client-side image maps), form controls, and groups of form
>           controls. [Priority 3]
>           For example, in HTML, specify shortcuts via the "accesskey"
>           attribute.
>           [77]Techniques for checkpoint 9.5
> 
>    10.1 [78]Until user agents allow users to turn off spawned windows, do
>           not cause pop-ups or other windows to appear and do not change
>           the current window without informing the user. [Priority 2]
>           For example, in HTML, avoid using a frame whose target is a new
>           window.
>           [79]Techniques for checkpoint 10.1
> 
>    10.2 [80]Until user agents support explicit associations between
>           labels and form controls, for all form controls with implicitly
>           associated labels, ensure that the label is properly
>           positioned. [Priority 2]
>           The label must immediately precede its control on the same line
>           (allowing more than one control/label per line) or be in the
>           line preceding the control (with only one label and one control
>           per line). [81]Refer also to checkpoint 12.4.
>           [82]Techniques for checkpoint 10.2
> 
>    10.3 [83]Until user agents (including assistive technologies) render
>           side-by-side text correctly, provide a linear text alternative
>           (on the current page or some other) for all tables that lay out
>           text in parallel, word-wrapped columns. [Priority 3]
>           Note. Please consult the definition of [84]linearized table.
>           This checkpoint benefits people with [85]user agents (such as
>           some [86]screen readers) that are unable to handle blocks of
>           text presented side-by-side; the checkpoint should not
>           discourage content developers from using tables to represent
>           [87]tabular information.
>           [88]Techniques for checkpoint 10.3
> 
>    10.4 [89]Until user agents handle empty controls correctly, include
>           default, place-holding characters in edit boxes and text areas.
>           [Priority 3]
>           For example, in HTML, do this for TEXTAREA and INPUT.
>           [90]Techniques for checkpoint 10.4
> 
>    10.5 [91]Until user agents (including assistive technologies) render
>           adjacent links distinctly, include non-link, printable
>           characters (surrounded by spaces) between adjacent links.
>           [Priority 3]
>           [92]Techniques for checkpoint 10.5
> 
>    11.1 Use W3C technologies when they are available and appropriate for
>           a task and use the latest versions when supported. [Priority 2]
>           Refer to the [93]list of references for information about where
>           to find the latest W3C specifications and [94][WAI-UA-SUPPORT]
>           for information about user agent support for W3C technologies.
>           [95]Techniques for checkpoint 11.1
> 
>    11.2 Avoid deprecated features of W3C technologies. [Priority 2]
>           For example, in HTML, don't use the [96]deprecated FONT
>           element; use style sheets instead (e.g., the 'font' property in
>           CSS).
>           [97]Techniques for checkpoint 11.2
> 
>    11.3 Provide information so that users may receive documents according
>           to their preferences (e.g., language, content type, etc.)
>           [Priority 3]
>           Note. Use content negotiation where possible.
>           [98]Techniques for checkpoint 11.3
> 
>    11.4 If, [99]after best efforts, you cannot create an [100]accessible
>           page, provide a link to an alternative page that uses W3C
>           technologies, is accessible, has [101]equivalent information
>           (or functionality), and is updated as often as the inaccessible
>           (original) page. [Priority 1]
>           [102]Techniques for checkpoint 11.4
> 
>    12.1 Title each frame to facilitate frame identification and
>           navigation. [Priority 1]
>           For example, in HTML use the "title" attribute on FRAME
>           elements.
>           [103]Techniques for checkpoint 12.1
> 
>    12.2 Describe the purpose of frames and how frames relate to each
>           other if it is not obvious by frame titles alone. [Priority 2]
>           For example, in HTML, use "longdesc," or a [104]description
>           link.
>           [105]Techniques for checkpoint 12.2
> 
>    12.3 Divide large blocks of information into more manageable groups
>           where natural and appropriate. [Priority 2]
>           For example, in HTML, use OPTGROUP to group OPTION elements
>           inside a SELECT; group form controls with FIELDSET and LEGEND;
>           use nested lists where appropriate; use headings to structure
>           documents, etc. [106]Refer also to guideline 3.
>           [107]Techniques for checkpoint 12.3
> 
>    12.4 Associate labels explicitly with their controls. [Priority 2]
>           For example, in HTML use LABEL and its "for" attribute.
>           [108]Techniques for checkpoint 12.4
> 
>    13.1 Clearly identify the target of each link. [Priority 2]
>           [109]Link text should be meaningful enough to make sense when
>           read out of context -- either on its own or as part of a
>           sequence of links. Link text should also be terse.
>           For example, in HTML, write "Information about version 4.3"
>           instead of "click here". In addition to clear link text,
>           content developers may further clarify the target of a link
>           with an informative link title (e.g., in HTML, the "title"
>           attribute).
>           [110]Techniques for checkpoint 13.1
> 
>    13.2 Provide metadata to add semantic information to pages and sites.
>           [Priority 2]
>           For example, use RDF ([111][RDF]) to indicate the document's
>           author, the type of content, etc.
>           Note. Some HTML [112]user agents can build navigation tools
>           from document relations described by the HTML LINK element and
>           "rel" or "rev" attributes (e.g., rel="next", rel="previous",
>           rel="index", etc.). [113]Refer also to checkpoint 13.5.
>           [114]Techniques for checkpoint 13.2
> 
>    13.3 Provide information about the general layout of a site (e.g., a
>           site map or table of contents). [Priority 2]
>           In describing site layout, highlight and explain available
>           accessibility features.
>           [115]Techniques for checkpoint 13.3
> 
>    13.4 Use navigation mechanisms in a consistent manner. [Priority 2]
>           [116]Techniques for checkpoint 13.4
> 
>    13.5 Provide navigation bars to highlight and give access to the
>           navigation mechanism. [Priority 3]
>           [117]Techniques for checkpoint 13.5
> 
>    13.6 Group related links, identify the group (for user agents), and,
>           [118]until user agents do so, provide a way to bypass the
>           group. [Priority 3]
>           [119]Techniques for checkpoint 13.6
> 
>    13.7 If search functions are provided, enable different types of
>           searches for different skill levels and preferences.
>           [Priority 3]
>           [120]Techniques for checkpoint 13.7
> 
>    13.8 Place distinguishing information at the beginning of headings,
>           paragraphs, lists, etc. [Priority 3]
>           Note. This is commonly referred to as "front-loading" and is
>           especially helpful for people accessing information with serial
>           devices such as speech synthesizers.
>           [121]Techniques for checkpoint 13.8
> 
>    13.9 Provide information about document collections (i.e., documents
>           comprising multiple pages.). [Priority 3]
>           For example, in HTML specify document collections with the LINK
>           element and the "rel" and "rev" attributes. Another way to
>           create a collection is by building an archive (e.g., with zip,
>           tar and gzip, stuffit, etc.) of the multiple pages.
>           Note. The performance improvement gained by offline processing
>           can make browsing much less expensive for people with
>           disabilities who may be browsing slowly.
>           [122]Techniques for checkpoint 13.9
> 
>    13.10 Provide a means to skip over multi-line ASCII art. [Priority 3]
>           Refer to [123]checkpoint 1.1 and [124]the example of ascii art
>           in the glossary.
>           [125]Techniques for checkpoint 13.10
> 
>         HTML
>                 Where a PRE element is used with substnatial punctuation
>                 and non-words, ask for text alternative.
> 
>    14.1 Use the clearest and simplest language appropriate for a site's
>           content. [Priority 1]
>           [126]Techniques for checkpoint 14.1
> 
>    14.2 Supplement text with graphic or auditory presentations where they
>           will facilitate comprehension of the page. [Priority 3]
>           [127]Refer also to guideline 1.
>           [128]Techniques for checkpoint 14.2
> 
>         HTML
>                 Provide libraries of accessible clip art to illustrate
>                 common concepts, or allow the author to build them.
> 
>    14.3 Create a style of presentation that is consistent across pages.
>           [Priority 3]
>           [129]Techniques for checkpoint 14.3
> 
> References snipped

-- 
Jan Richards
jan.richards@utoronto.ca
Access Software Designer
Adaptive Technology Resource Centre
University of Toronto
(416) 946-7060

Received on Monday, 21 February 2000 14:56:33 UTC