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steve: updated text alternative length advice

From: poot <cvsmail@w3.org>
Date: Thu, 16 Feb 2012 10:07:38 -0500
To: public-html-diffs@w3.org
Message-Id: <E1Ry2vq-0006TK-1p@jay.w3.org>
steve: updated text alternative length advice

http://dev.w3.org/cvsweb/html5/alt-techniques/Overview.html?r1=1.86&r2=1.87&f=h

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RCS file: /sources/public/html5/alt-techniques/Overview.html,v
retrieving revision 1.86
retrieving revision 1.87
diff -u -d -r1.86 -r1.87
--- Overview.html	15 Dec 2011 13:18:58 -0000	1.86
+++ Overview.html	16 Feb 2012 15:06:58 -0000	1.87
@@ -675,12 +675,13 @@
 </style>
 </head>
 <body style="display: inherit;"><div class="head"><p><a href="http://www.w3.org/"><img src="http://www.w3.org/Icons/w3c_home" alt="W3C" width="72" height="48"></a></p><h1 class="title" id="title">HTML5: Techniques for providing useful text alternatives</h1>
-<h2 id="w3c-editor-s-draft-26-may-2011">W3C Editor's Draft 15 December 2011</h2><dl><dt>This version:</dt><dd><a href="http://dev.w3.org/html5/alt-techniques/">http://dev.w3.org/html5/alt-techniques/</a></dd><dt>Latest published version:</dt><dd><a href="http://www.w3.org/TR/html-alt-techniques/">http://www.w3.org/TR/html-alt-techniques/</a></dd><dt>Latest editor's draft:</dt><dd><a href="http://dev.w3.org/html5/alt-techniques/">http://dev.w3.org/html5/alt-techniques/</a></dd>
+<h2 id="w3c-editor-s-draft-26-may-2011">W3C Editor's Draft 16 February 2012</h2><dl><dt>This version:</dt><dd><a href="http://dev.w3.org/html5/alt-techniques/">http://dev.w3.org/html5/alt-techniques/</a></dd><dt>Latest published version:</dt><dd><a href="http://www.w3.org/TR/html-alt-techniques/">http://www.w3.org/TR/html-alt-techniques/</a></dd><dt>Latest editor's draft:</dt><dd><a href="http://dev.w3.org/html5/alt-techniques/">http://dev.w3.org/html5/alt-techniques/</a></dd>
 
 <dt>Developer edition:</dt>
 <dd><a href="http://dev.w3.org/html5/alt-techniques/developer.html">http://dev.w3.org/html5/alt-techniques/developer.html</a> </dd>
 <dt>Editor:</dt><dd><span>Steve Faulkner</span>, The Paciello Group <span class="ed_mailto"><a href="mailto:sfaulkner@paciellogroup.com">sfaulkner@paciellogroup.com</a></span> </dd>
-</dl><p class="copyright"><a href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright">Copyright</a> &copy; 2011 <a href="http://www.w3.org/"><acronym title="World Wide Web Consortium">W3C</acronym></a><sup>&reg;</sup> (<a href="http://www.csail.mit.edu/"><acronym title="Massachusetts Institute of Technology">MIT</acronym></a>, <a href="http://www.ercim.eu/"><acronym title="European Research Consortium for Informatics and Mathematics">ERCIM</acronym></a>, <a href="http://www.keio.ac.jp/">Keio</a>), All Rights Reserved. W3C <a href="http://www.w3.org/Consortium/Legal/ipr-notice#Legal_Disclaimer">liability</a>, <a href="http://www.w3.org/Consortium/Legal/ipr-notice#W3C_Trademarks">trademark</a> and <a href="http://www.w3.org/Consortium/Legal/copyright-documents">document use</a> rules apply.</p><hr></div>
+</dl>
+<p class="copyright"><a href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright">Copyright</a> &copy; 2012 <a href="http://www.w3.org/"><acronym title="World Wide Web Consortium">W3C</acronym></a><sup>&reg;</sup> (<a href="http://www.csail.mit.edu/"><acronym title="Massachusetts Institute of Technology">MIT</acronym></a>, <a href="http://www.ercim.eu/"><acronym title="European Research Consortium for Informatics and Mathematics">ERCIM</acronym></a>, <a href="http://www.keio.ac.jp/">Keio</a>), All Rights Reserved. W3C <a href="http://www.w3.org/Consortium/Legal/ipr-notice#Legal_Disclaimer">liability</a>, <a href="http://www.w3.org/Consortium/Legal/ipr-notice#W3C_Trademarks">trademark</a> and <a href="http://www.w3.org/Consortium/Legal/copyright-documents">document use</a> rules apply.</p><hr></div>
 
 
 
@@ -1617,7 +1618,7 @@
 </div>
 <div class="section" id="m5">
 <h4 id="he"><span class="secno">4.1.3 </span>How long should a  text alternative be?</h4>
-<p>The answer to this question very much depends on the context an image is being used in. While there are no definitive right or wrong lengths for text alternatives provided using the <code>img</code> elements <code>alt</code> attribute, the general consensus is that if the text alternative is longer than  75-100 characters (1 to 2 sentences), it should not be considered a short text alternative and should not be presented using the <code>alt</code> attribute.</p>
+<p>The answer to this question very much depends on the context an image is being used in. While there are no definitive right or wrong lengths for text alternatives provided using the <code>img</code> elements <code>alt</code> attribute or the <code>figcaption</code> element, the general consensus is that if the text alternative is longer than  75-100 characters (1 to 2 sentences), it should not be considered a short text alternative and should not be presented using the <code>alt</code> attribute or the <code>figcaption</code> element (in the case where it provides a text alternative for an image). </p>
 </div>
 </div>
 <div class="section" id="m6">
@@ -1650,11 +1651,11 @@
 </ul>
 <h5 id="hi">Disadvantages:</h5>
 <ul>
-  <li>The <code>figure</code> and <code>figcaption</code> elements are not currently accessibility supported by browsers or assistive technology. </li>
+  <li>The <code>figure</code> and <code>figcaption</code> elements are not currently accessibility supported by the majority of browsers. </li>
   </ul>
 
 <div class="example">
-  <p>Until the <code>figure</code> and <code>figcaption</code> elements are accessibility supported by browsers and/or assistive technology it is recommended that <code>role=&quot;group&quot;</code> be used on the figure element and in the case where the <code>figcaption</code> content is the text alternative,  provide a label for the image in the <code>alt</code> attribute. These recommendations are illustrated in following example:</p>
+  <p>Until the <code>figure</code> and <code>figcaption</code> elements are widely accessibility supported by browsers and/or assistive technology it is recommended that <code>role=&quot;group&quot;</code> be used on the figure element and in the case where the <code>figcaption</code> content is the text alternative,  provide a label for the image in the <code>alt</code> attribute. These recommendations are illustrated in following example:</p>
   <p><strong>Example C: </strong></p>
   <div class="element1">
     <p><img src="images/shadows.jpg" width="400" height="310"></p>

Index: developer.html
===================================================================
RCS file: /sources/public/html5/alt-techniques/developer.html,v
retrieving revision 1.10
retrieving revision 1.11
diff -u -d -r1.10 -r1.11
--- developer.html	15 Dec 2011 13:18:58 -0000	1.10
+++ developer.html	16 Feb 2012 15:06:58 -0000	1.11
@@ -664,14 +664,16 @@
 </style>
 </head>
 <body style="display: inherit;"><div class="head"><p><a href="http://www.w3.org/"><img src="http://www.w3.org/Icons/w3c_home" alt="W3C" width="72" height="48"></a></p><h1 class="title" id="title">HTML5: Techniques for providing useful text alternatives</h1>
-<h2 id="w3c-editor-s-draft-26-may-2011">W3C Editor's Draft 15 December 2011</h2><dl><dt>Latest editor's draft:</dt><dd><a href="http://dev.w3.org/html5/alt-techniques/">http://dev.w3.org/html5/alt-techniques/</a></dd><dt>Editor:</dt><dd><span>Steve Faulkner</span>, The Paciello Group <span class="ed_mailto"><a href="mailto:sfaulkner@paciellogroup.com">sfaulkner@paciellogroup.com</a></span> </dd>
-</dl><p class="copyright"><a href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright">Copyright</a> &copy; 2011 <a href="http://www.w3.org/"><acronym title="World Wide Web Consortium">W3C</acronym></a><sup>&reg;</sup> (<a href="http://www.csail.mit.edu/"><acronym title="Massachusetts Institute of Technology">MIT</acronym></a>, <a href="http://www.ercim.eu/"><acronym title="European Research Consortium for Informatics and Mathematics">ERCIM</acronym></a>, <a href="http://www.keio.ac.jp/">Keio</a>), All Rights Reserved. W3C <a href="http://www.w3.org/Consortium/Legal/ipr-notice#Legal_Disclaimer">liability</a>, <a href="http://www.w3.org/Consortium/Legal/ipr-notice#W3C_Trademarks">trademark</a> and <a href="http://www.w3.org/Consortium/Legal/copyright-documents">document use</a> rules apply.</p><hr></div>
+<h2 id="w3c-editor-s-draft-26-may-2011">W3C Editor's Draft 16 February 2012</h2><dl><dt>Latest editor's draft:</dt><dd><a href="http://dev.w3.org/html5/alt-techniques/">http://dev.w3.org/html5/alt-techniques/</a></dd><dt>Editor:</dt><dd><span>Steve Faulkner</span>, The Paciello Group <span class="ed_mailto"><a href="mailto:sfaulkner@paciellogroup.com">sfaulkner@paciellogroup.com</a></span> </dd>
+</dl><p class="copyright"><a href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright">Copyright</a> &copy; 2012 <a href="http://www.w3.org/"><acronym title="World Wide Web Consortium">W3C</acronym></a><sup>&reg;</sup> (<a href="http://www.csail.mit.edu/"><acronym title="Massachusetts Institute of Technology">MIT</acronym></a>, <a href="http://www.ercim.eu/"><acronym title="European Research Consortium for Informatics and Mathematics">ERCIM</acronym></a>, <a href="http://www.keio.ac.jp/">Keio</a>), All Rights Reserved. W3C <a href="http://www.w3.org/Consortium/Legal/ipr-notice#Legal_Disclaimer">liability</a>, <a href="http://www.w3.org/Consortium/Legal/ipr-notice#W3C_Trademarks">trademark</a> and <a href="http://www.w3.org/Consortium/Legal/copyright-documents">document use</a> rules apply.</p><hr></div>
 
 
 
 
 
 
+   
+
     <div id="abstract" class="introductory section"><!--OddPage--><h2><span class="secno">1. </span>Abstract</h2>
 
 <p>This document contains author conformance requirements for use of the alt attribute in HTML5 and best practice guidance for authors of HTML documents on providing text alternatives for images. </p>
@@ -1445,13 +1447,13 @@
   
 </div>
 <h5>Note:</h5>
-<p class="note">In examples A &amp; B above, the <code>alt </code>attribute is be used a container for a text label that identifies the image and provides an implicit association between the image and the text that describes it. The use of the <code>alt</code> attribute in this context is recommended as a bridging technique until the <code>figure</code> and <code>figcaption</code> element semantics are implemented in browsers and assistive technology. Its use conforms to WCAG 2.0 [<a href="#bib-WCAG20">WCAG20</a>]. Its use is a willful violation of <a href="#bib-HTML5">HTML5</a> [HTML5].</p>
+<p class="note"> In examples A &amp; B above, the <code>alt </code>attribute is be used a a container for a text label that identifies the image and provides an implicit association between the image and the text that describes it. The use of the <code>alt</code> attribute in this context is recommended as a bridging technique until the <code>figure</code> and <code>figcaption</code> element semantics are implemented in browsers and assistive technology. Its use conforms to WCAG 2.0 [<a href="#bib-WCAG20">WCAG20</a>]. Its use is a willful violation of <a href="#bib-HTML5">HTML5</a> [HTML5].</p>
 </div>
 <div class="section" id="sec13">
 <h3 id="captcha"><span class="secno">3.13 </span>CAPTCHA Images </h3>
 <p><a title="http://www.w3.org/TR/WCAG20/#atdef" href="http://www.w3.org/TR/WCAG20/#CAPTCHAdef">CAPTCHA</a> stands for   "Completely Automated Public Turing test to tell Computers and Humans Apart".   CAPTCHA images are used for security purposes to confirm that <a title="http://www.w3.org/TR/WCAG20/#contentdef" href="http://www.w3.org/TR/WCAG20/#contentdef">content</a> is being accessed by   a person rather than a computer. This authentication is done through visual   verification of an image. CAPTCHA typically presents an image with characters or   words in it that the user is to re-type. The image is usually distorted and has   some noise applied to it to make the characters difficult to read. </p>
 <p>Provide <a title="http://www.w3.org/TR/WCAG20/#text-altdef" href="http://www.w3.org/TR/WCAG20/#text-altdef">text alternatives</a> that   identify and describe the purpose of the <a title="http://www.w3.org/TR/WCAG20/#non-text-contentdef" href="http://www.w3.org/TR/WCAG20/#non-text-contentdef">non-text content</a>,   and provide alternative forms of the CAPTCHA using output modes for different   types of sensory perception. For instance provide an audio alternative along   with the visual image. Locate the audio option right next to the visual one.   This helps but is still problematic for people without sound cards, the   deaf-blind, and some low hearing people. Another method is to include a form   that asks a question along with the visual image. This helps but is can be   problematic for people with cognitive impairments. </p>
-<p class="warning">It is strongly recommended that alternatives to CAPTCHA be used, as all forms of CAPTCHA introduce unacceptable barriers to entry for users with disabilities. Further information is available in the W3C's <a href="http://www.w3.org/TR/turingtest/">Inaccessibility of CAPTCHA</a>.</p>
+<p><span class="warning">It is strongly recommended that alternatives to CAPTCHA be used, as all forms of CAPTCHA introduce unacceptable barriers to entry for users with disabilities. Further information is available in the W3C's <a href="http://www.w3.org/TR/turingtest/">Inaccessibility of CAPTCHA</a>.</span></p>
 <h4 id="hbl">Example 13.1</h4>
 <p>This example shows a <a href="http://recaptcha.net/learnmore.html">CAPTCHA test</a> which uses a distorted image of text. The text alternative in the alt attribute provides instructions for a user in the case where she cannot access the image content. </p>
 <div class="example">
@@ -1605,7 +1607,7 @@
 </div>
 <div class="section" id="m5">
 <h4 id="he"><span class="secno">4.1.3 </span>How long should a  text alternative be?</h4>
-<p>The answer to this question very much depends on the context an image is being used in. While there are no definitive right or wrong lengths for text alternatives provided using the <code>img</code> elements <code>alt</code> attribute, the general consensus is that if the text alternative is longer than  75-100 characters (1 to 2 sentences), it should not be considered a short text alternative and should not be presented using the <code>alt</code> attribute.</p>
+<p>The answer to this question very much depends on the context an image is being used in. While there are no definitive right or wrong lengths for text alternatives provided using the <code>img</code> elements <code>alt</code> attribute or the <code>figcaption</code> element, the general consensus is that if the text alternative is longer than  75-100 characters (1 to 2 sentences), it should not be considered a short text alternative and should not be presented using the <code>alt</code> attribute or the <code>figcaption</code> element (in the case where it provides a text alternative for an image). </p>
 </div>
 </div>
 <div class="section" id="m6">
@@ -1638,11 +1640,11 @@
 </ul>
 <h5 id="hi">Disadvantages:</h5>
 <ul>
-  <li>The <code>figure</code> and <code>figcaption</code> elements are not currently accessibility supported by browsers or assistive technology. </li>
+  <li>The <code>figure</code> and <code>figcaption</code> elements are not currently accessibility supported by the majority of browsers. </li>
   </ul>
 
 <div class="example">
-  <p>Until the <code>figure</code> and <code>figcaption</code> elements are accessibility supported by browsers and/or assistive technology it is recommended that <code>role=&quot;group&quot;</code> be used on the figure element and in the case where the <code>figcaption</code> content is the text alternative,  provide a label for the image in the <code>alt</code> attribute. These recommendations are illustrated in following example:</p>
+  <p>Until the <code>figure</code> and <code>figcaption</code> elements are widely accessibility supported by browsers and/or assistive technology it is recommended that <code>role=&quot;group&quot;</code> be used on the figure element and in the case where the <code>figcaption</code> content is the text alternative,  provide a label for the image in the <code>alt</code> attribute. These recommendations are illustrated in following example:</p>
   <p><strong>Example C: </strong></p>
   <div class="element1">
     <p><img src="images/shadows.jpg" width="400" height="310"></p>
@@ -1655,7 +1657,7 @@
  
 </div>
  <h5>Note:</h5>
- <p class="note1"> In example C above, the <code>alt </code>attribute is be used a a container for a text label that identifies the image and provides an implicit association between the image and the text that describes it. The use of the <code>alt</code> attribute in this context is recommended as a bridging technique until the <code>figure</code> and <code>figcaption</code> element semantics are implemented in browsers and assistive technology. Its use conforms to WCAG 2.0 [<a href="#bib-WCAG20">WCAG20</a>]. Its use is a willful violation of <a href="#bib-HTML5">HTML5</a> [HTML5].</p>
+ <p class="note"> In example C above, the <code>alt </code>attribute is be used a container for a text label that identifies the image and provides an implicit association between the image and the text that describes it. The use of the <code>alt</code> attribute in this context is recommended as a bridging technique until the <code>figure</code> and <code>figcaption</code> element semantics are implemented in browsers and assistive technology. Its use conforms to WCAG 2.0 [<a href="#bib-WCAG20">WCAG20</a>]. Its use is a willful violation of <a href="#bib-HTML5">HTML5</a> [HTML5].</p>
 </div>
 <h4 id="nested">4.2.1 Using nested <code>figure</code> elements </h4>
 <p>In cases where there is a group of related images each having an associated caption, it is recommended that nested <code>figure</code> and <code>figcaption</code> elements be used. </p>
Received on Thursday, 16 February 2012 15:07:43 GMT

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