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Alt-Techniques Formal Objection Rationale

From: Lachlan Hunt <lachlan.hunt@lachy.id.au>
Date: Mon, 19 Nov 2012 13:19:31 +0100
Message-ID: <50AA23D3.7090408@lachy.id.au>
To: public-html <public-html@w3.org>
At the HTML F2F, I was asked to provide rationale for my previously
filed formal objection to "HTML5: Techniques for providing useful text
alternatives" (alt-techniques).

(Note: The objection was filed on my own behalf, not on behalf of my
employer)

http://dev.w3.org/html5/status/formal-objection-status.html
http://lists.w3.org/Archives/Public/www-archive/2011May/0051.html

This email covers both of my objections to the alt-techniques spec,
regarding publishing on the Rec track and contradicting HTML5. This
outlines a few areas of contention and compares equivalent sections of
both the alt-techniques and HTML5 drafts.

In each case, the section heading and normative requirement from
Alt-Techniques, and (where applicable) the equivalent heading and
requirement HTML5 are stated, followed by a comment about the problem
and proposed solutions.

I have not had time to go through and analyse the complete specification
for differences, so the following are selected examples sufficient to
illustrate my problem with the alt-techniques draft and justify my
objections.

---

Alt-Techniques:
  *Abstract*

  "All normative content in the HTML5 specification, unless
   specifically overridden by this specification, is intended
   to be the basis for this specification."

I object to any normative content of the alt-techniques draft overriding
normative requirements in HTML5.

Proposed Solution:
1. Remove this clause "unless specifically overridden".
2. Resolve any significant differences (some of which are discussed
below) by either changing alt-techniques, or by pursuing relevant
changes in HTML5.

---

Alt-Techniques:
  *A link or button containing only an image*

  "When an a element that is a hyperlink, or a button element, has no
   text content but contains one or more images, the alt attributes
   must contain text that together convey the purpose of the link or
   button."

HTML5:
  *A link or button containing nothing but the image*

  "When an a element that creates a hyperlink, or a button element, has
   no textual content but contains one or more images, the alt
   attributes must contain text that together convey the purpose of the
   link or button." -- html5

This section contains an unnecessary normative redefinition of a
requirement in HTML5. The requirements are phrased slightly differently,
but have effectively the same meaning.

Proposed solutions:
1. Mark this section in alt-techniques as non-normative to ensure that
   HTML5 takes precedence in the event of any conflict.
2. Include a link to the equivalent section in HTML5.

---

Alt-Techniques:
  *Graphical representations: charts, diagrams, graphs, maps, illustrations*

  "The full text alternative may be provided in the alt attribute, or a
   shorter text alternative may be provided in the alt attribute or in
   a programmatically associated element, and a longer programmatically
   associated text alternative provided in the same document or in a
   linked document."

HTML5:
  *A phrase or paragraph with an alternative graphical representation:
charts, diagrams, graphs, maps, illustrations*

  "The text must be given in the alt attribute, and must convey the
   same message as the image specified in the src attribute."

This section is incompatible with the requirements in HTML5 because it
provides conflicting advice to users about the same types of images.

Proposed solutions:
1. Mark this section in alt-techniques as non-normative to ensure that
   HTML5 takes precedence in the event of any conflict.
2. Make the advice compatible by either changing alt-techniques, or by
   pushing for a compatible change in HTML5.  (I take no position with
   regards to which advice is better - just that the normative
   requirements in HTML5 and the advice in alt-techniques should be
   not contradict each other.)
3. Include a link to the equivalent section in HTML5.

---

Alt-Techniques:
  *Images of text*

  "Sometimes, an image only contains text, and the purpose of the image
   is to display text using visual effects and /or fonts. It is
   strongly recommended that text styled using CSS be used, but if this
   is not possible, in most of these cases, the content of the alt
   attribute should consist of the same text as written in the image
   itself."

HTML5:
  *Text that has been rendered to a graphic for typographical effect*

  "Sometimes, an image just consists of text, and the purpose of the
   image is not to highlight the actual typographic effects used to
   render the text, but just to convey the text itself.

  "In such cases, the alt attribute must be present but must consist of
   the same text as written in the image itself."

This section contains an unnecessary normative redefinition of a
requirement in HTML5. The requirements are phrased slightly differently,
but have effectively the same meaning.

Proposed solutions:
1. Mark this section in alt-techniques as non-normative to ensure that
   HTML5 takes precedence in the event of any conflict.
2. Include a link to the equivalent section in HTML5.

---

Alt-Techniques:
  *Images that include text*

  "Sometimes, an image consists of a graphics such as a chart and
   associated text. In this case it is recommended that the text in the
   image is included in text alternative."

It's not entirely clear if this is meant as a normative requirement or
not.  Although the term "recommended" is included, it is not highlighted
as an RFC2119 term. But for the purposes of this email, I will assume it
is intended to be a normative requirement.

I could not identify any specific section in HTML5 that correlates with
this advice specifically, but HTML5 does require, for charts and graphs,
that the alt text convey the same message as the image.  It seems,
therefore, that this section in alt-techniques is a more specific
application of the general technique required in HTML5, and is thus
effectively a redefinition of existing requirements.

Proposed solutions:
1. Mark this section in alt-techniques as non-normative to ensure that
   HTML5 takes precedence in the event of any conflict.

---

Alt-Techniques:
  *A purely decorative image that doesn't add any information*

  "Purely decorative images must be marked up so they can be ignored by
   assistive technology with a null alt attribute (alt="") or
   preferably use CSS techniques. If the image isn't providing the user
   any informative content or enhancing greater understanding of the
   content, then the alt attribute must be empty."

HTML5:
  *A purely decorative image that doesn't add any information*

  "If an image is decorative but isn't especially page-specific ... the
   image should be specified in the site's CSS, not in the markup of
   the document.

  "However, a decorative image that isn't discussed by the surrounding
   text but still has some relevance can be included in a page using
   the img element. Such images are decorative, but still form part of
   the content. In these cases, the alt attribute must be present but
   its value must be the empty string."

This section contains an unnecessary normative redefinition of a
requirement in HTML5. The requirements are phrased slightly differently,
but have effectively the same meaning.

Proposed solutions:
1. Mark this section in alt-techniques as non-normative to ensure that
   HTML5 takes precedence in the event of any conflict.
2. Include a link to the equivalent section in HTML5.

---

Alt-Techniques:
  *Icons*

  "In some cases, the icon is supplemental to a text label conveying
   the same meaning. In those cases, an empty alt attribute must
   provided.

  "In other cases the icon adds emphasis to text content that needs to
   be conveyed textually, In such cases a text alternative must be
   provided."

HTML5:
  *A short phrase or label with an alternative graphical representation:
icons, logos*

  "In some cases, the icon is supplemental to a text label conveying
   the same meaning. In those cases, the alt attribute must be present
   but must be empty.

  "In other cases, the icon has no text next to it describing what it
   means; the icon is supposed to be self-explanatory. In those cases,
   an equivalent textual label must be given in the alt attribute."

This section contains an unnecessary normative redefinition of a
requirement in HTML5. The requirements are phrased slightly differently,
but have effectively the same meaning.

Proposed solutions:
1. Mark this section in alt-techniques as non-normative to ensure that
   HTML5 takes precedence in the event of any conflict.
2. Include a link to the equivalent section in HTML5.

-- 
Lachlan Hunt
http://lachy.id.au/
Received on Monday, 19 November 2012 12:19:58 UTC

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