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These aren't the SCs you're looking for ... (mis)adventures in WCAG 2.x interpretation and audits / a11yTO / 24 October 2019


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WCAG is supposed to give us a reasonably objective way of saying whether or not the sites we are building/auditing are "accessible" (to a particular baseline). However, they are only as useful as our understanding and interpretation of the actual guidelines' normative text. And of course they're not perfect - with some omissions, handwaving, and straight up loopholes. So where does this leave developers and auditors? In this talk, Patrick may not have all the answers, but he'll have a good rant around the subject anyway...

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These aren't the SCs you're looking for ... (mis)adventures in WCAG 2.x interpretation and audits / a11yTO / 24 October 2019

  1. 1. These aren't the SCs you're looking for... (mis)adventures in WCAG 2.x interpretation and audits Patrick H. Lauke / a11yTO / Toronto / 24 October 2019
  2. 2. about me... ▪  principal accessibility engineer at The Paciello Group ▪  occasional W3C AGWG member ▪  WCAG trash panda ▪  known for my rants, not my brevity...
  3. 3. what really grinds my gears... ▪  doing accessibility audits ▪  advising and reviewing the work of other engineers doing audits ▪  being active on accessibility mailing lists (WebAIM, W3C, ...) ...and far too often, the same question always bubbles up
  4. 4. “which success criterion can I fail this under?”
  5. 5. depends™
  6. 6. far too often, auditors clearly dislike something, and look for a justification to fail it ...
  7. 7. overstep the boundaries of WCAG SCs claim something has to be fixed/changed "to pass WCAG" when it normatively doesn't
  8. 8. we are not lawyers (or judges) but our audits and evaluations often have some legal dimension to them. ▪  evaluations should be as objective as possible ▪  evaluations should be consistent ...of course, this is easier said than done
  9. 9. WCAG is built on the idea that success criteria can be evaluated clearly, unambiguously and consistently... ...but that's not always the case
  10. 10. only a few cherry-picked examples ... otherwise we'd be here a few more hours
  11. 11. WCAG success criteria are often misunderstood and/or misinterpreted leads to wrong, or at least inconsistent, error reporting
  12. 12. 2.4.6 Headings and Labels (AA) Headings and labels describe topic or purpose. this doesn't mandate the use of headings and labels ... only that if a page uses headings and labels, they must be descriptive. it also doesn't mandate that headings and labels be correctly marked-up - that's the job of 1.3.1 Info and Relationships and (where it affects "accessible name" of controls) 4.1.2 Name, Role, Value ). lastly, if labels aren't there, it's a 3.3.2 Labels or Instructions problem. “
  13. 13. <input type="text"> passes 2.4.6 Headings and Labels fails 3.3.2 Labels or Instructions fails 4.1.2 Name, Role, Value
  14. 14. <p class="heading1">I'm a heading</p> <p>First name</p> <input type="text"> passes 2.4.6 Headings and Labels fails 1.3.1 Info and Relationships fails 4.1.2 Name, Role, Value
  15. 15. 3.3.2 Labels or Instructions (A) Labels or instructions are provided when content requires user input. again, this doesn't mandate that labels be marked-up as <label> and properly associated with form controls - that's covered by 1.3.1 Info and Relationships and (where it affects "accessible name" of controls) 4.1.2 Name, Role, Value . “
  16. 16. <p>First name</p> <input type="text"> passes 3.3.2 Labels or Instructions fails 4.1.2 Name, Role, Value fails 1.3.1 Info and Relationships
  17. 17. 2.1.1 Keyboard (A) All functionality of the content is operable through a keyboard interface [...] doesn't say anything about which keys are needed to operate controls/functionality “
  18. 18. <a href="#" onclick="..." role="button">fake button</a> passes 2.1.1 Keyboard even though it doesn't respond to SPACE like real button would
  19. 19. 3.2.3 Consistent Navigation (AA) Navigational mechanisms that are repeated on multiple Web pages within a set of Web pages occur in the same relative order each time they are repeated, unless a change is initiated by the user. this only normatively requires the relative order of navigation (in relation to other page components) to be consistent - nothing more. doesn't mandate that navigation should be same, work the same, etc across pages “
  20. 20. 1.3.3 Sensory Characteristics (A) Instructions provided for understanding and operating content do not rely solely on sensory characteristics of components such as shape, color, size, visual location, orientation, or sound. this only relates specifically to instructions ... and not whether or not sensory characteristics are used - this is covered by other SCs, like 1.4.1 Use of Color or even 1.1.1 Non-Text Content . “
  21. 21. WCAG success criteria and cascades of fail ...
  22. 22. cascade of fail <a href="..."> <img src="..."> </a> fails multiple criteria ...need to consistently report these, but easy to forget and tedious to do...
  23. 23. "speculative" cascade of fail <div>Read more</div> fails 2.1.1 Keyboard ... but also 4.1.2 Name, Role, Value and if it acts as a link, also 2.4.4 Link Purpose (In Context) ?
  24. 24. auditor education / consistency problems... internal training and resources can help
  25. 25. more problematic are issues caused by WCAG SCs that are vague , incomplete or otherwise lacking
  26. 26. WCAG 2.x is not perfect written by well-meaning, but fallible humans (after all)
  27. 27. WCAG success criteria can be subjective ...
  28. 28. subjective interpretation? ▪   1.1.1 All non-text content [...] has a text alternative that serves the equivalent purpose - but what's the purpose? ▪   1.3.1 Information, structure, and relationships conveyed through presentation [...] - where do you draw the line? ▪   2.4.6 Headings and labels describe topic or purpose - what's "descriptive" exactly?
  29. 29. <div class="footer"> ... </div> do you fail 1.3.1 Info and Relationships because they don't use <footer> or role="contentinfo" ? is it not clear from context? <a href="/">home</p> <a href="...">products</a> <a href="...">contact</a> do you fail 1.3.1 Info and Relationships because they didn't wrap this in a <ul> even when styled as an inline set of three links?
  30. 30. "I think what the founding fathers of WCAG meant to say..."
  31. 31. understanding documents and techniques try to clarify... normative versus non-normative
  32. 32. understanding / techniques can't provide examples of all possible scenarios
  33. 33. beyond the need for subjective interpretation WCAG success criteria can have odd loopholes ...
  34. 34. 2.4.7 Focus Visible (AA) Any keyboard operable user interface has a mode of operation where the keyboard focus indicator is visible. but what does visible mean? it's not normatively defined... “
  35. 35. a single extra pixel shown on focus is arguably visible
  36. 36. WCAG 2.1 decided not to modify 2.0 SCs, patched loopholes with more SCs but these new SCs also ended up having some loopholes
  37. 37. 1.4.11 Non-text Contrast (AA) The visual presentation of the following have a contrast ratio of at least 3:1 against adjacent color(s): ▪  User Interface Components: Visual information required to identify user interface components and states [...] ▪  Graphical Objects: [...] “
  38. 38. much better...that pixel has a 3:1 contrast ratio now
  39. 39. 1.4.11 Non-text Contrast (AA) The visual presentation of the following have a contrast ratio of at least 3:1 against adjacent color(s): [...] note that this only applies normatively to adjacent colors ... doesn't apply to contrast between different colors used for states of the same control “
  40. 40. fails 1.4.11 Non-text Contrast
  41. 41. passes 1.4.11 Non-text Contrast
  42. 42. passes 1.4.11 Non-text Contrast. but wait, does it fail 1.4.1 Use of Color ?
  43. 43. 1.4.1 Use of Color (A) Color is not used as the only visual means of conveying information, indicating an action, prompting a response, or distinguishing a visual element. but there's an escape clause in the non-normative F73 failure technique that tries to redefine, by the backdoor, what "color" means... “
  44. 44. F73: Failure of Success Criterion 1.4.1 due to creating links that are not visually evident without color vision Note 1: Red and Pink are the same color (hue) but they have different lightness (which is not color ). So red and pink would pass the requirement for "not distinguished by color (hue) alone" since they differ by lightness (which is not color) - as long as the difference in lightness (contrast) is 3:1 or greater WAT? “
  45. 45. ...but we'll fix it in WCAG 2.2 (?) 2.4.11 Focus Visible Enhanced (Level AA)
  46. 46. SCs that are overly specific... and then end up only applying to very specific cases
  47. 47. 1.4.10 Reflow (AA) Content can be presented without loss of information or functionality, and without requiring scrolling in two dimensions for: ▪  Vertical scrolling content at a width equivalent to 320 CSS pixels ▪  Horizontal scrolling content at a height equivalent to 256 CSS pixels [...] meant to help low vision users that require up to 400% zoom, but ended up too specific - only normatively applies at those exact values “
  48. 48. @media ( width: 320px ) { ... }
  49. 49. 1.4.12 Text Spacing (AA) In content implemented using markup languages that support the following text style properties, no loss of content or functionality occurs by setting all of the following and by changing no other style property: ▪  Line height (line spacing) to at least 1.5 times the font size ▪  Spacing following paragraphs to at least 2 times the font size ▪  Letter spacing (tracking) to at least 0.12 times the font size ▪  Word spacing to at least 0.16 times the font size [...] only those exact values and over - if content breaks/stops working at line height of 1.4 instead of 1.5, not a failure... “
  50. 50. use JavaScript to detect line height and fix only if 1.5 or higher
  51. 51. even after years of auditing, I sometimes have weird moments of realisation seeing SCs, and what they say/apply to, in a new light
  52. 52. same discussions about applicability and interpretation even happen within the AGWG
  53. 53. WCAG success criteria need to be testable ... but this doesn't allow for nuance
  54. 54. WCAG SCs are binary you either pass or fail
  55. 55. sometimes the values/thresholds are just arbitrary lines in the sand ...
  56. 56. no weighting given to impact or frequency of a particular fail, or how bad a failure is off the mark sometime, you just want to say something's a minor or soft fail , but distinction doesn't exist
  57. 57. fail a single SC and you can't really claim to be conformant
  58. 58. loopholes , omissions and subjective requirements can and will be exploited auditors aren't the only ones who try to find these gaps...
  59. 59. what do we do about this?
  60. 60. join the debate/discussion (more open nowadays)
  61. 61. more consistent Accessibility Compliance Testing (ACT)
  62. 62.
  63. 63. the next generation of accessibility guidelines...
  64. 64. moving away from binary pass/fail conformance (or trying)
  65. 65. potentially complex scoring/rating system more nuanced but too complex ?
  66. 66. the meantime though...
  67. 67. don't creatively reinterpret what an SC says to fit your agenda whether you're a developer or an auditor doing an evaluation
  68. 68. as auditor, you do your client a disservice by not making clear what is and isn't a normative failure ...what happens when a clued-up client rightly challenges your claim? all your other results lose credibility...
  69. 69. be conservative in your pass / fail assessments document your hesitation, clearly state when something's "more of a suggestion" than a hard failure
  70. 70. further reading...
  71. 71. join my WCAG Trash Panda Webring : ▪  Fixes to WCAG 2.1 Understanding 2.4.6 and 3.3.2 #612 ▪  Edits to 135 failure #890 ▪  Proposal for color and contrast (1.3.1, 1.4.1, 1.4.3., 1.4.6, 1.4.11) #901 ▪  Should role button and input button be a WCAG fail if cannot be activated using space? #857 ▪  Does SC 1.4.11 require comparing focused and non-focused states #541 ▪  Ambiguity in understanding for 1.3.3 sensory characteristics #750 ▪  Bad/incomplete example for Understanding 3.3.2 #755
  72. 72. ▪  "at least" should be "at most" in WCAG 2.1 SC 1.4.12 #635 ▪  Expand 1.4.10 to apply 'down to' instead of 'at' #698 ▪  2.4.7 Focus Visible - what counts as "visible"? #302 ▪  Must the tooltip of icons match the accessible name? (for "Label in Name", SC 2.5.3) #891 ▪  Keyboard operation with assistive technology: 2.1.1 or 4.1.2? #878 ▪  Can title on links (e.g. linked icon) as sole source of accName ever pass 1.1.1? #867 (side discussion about high contrast mode and reponsibility of user agents) ▪  Error of the User Agents part of WCAG or not #866
  73. 73. ▪  1.4.5 / 1.4.9 Image of Text and <text> inside SVGs #773 ▪  Revisiting imbalance between 1.2.4 Captions (Live) (AA) and 1.2.9 Audio- only (Live) (AAA) #795 ▪  ARIA in HTML conformance to conform WCAG ? #717 ▪  Failure technique F94 (1.4.4 resize text): remove "1280 pixels wide" step in test procedure #704 ▪  Contrast Ratio Math and Related Visual Issues #695 ▪  Include font weight for color contrast tests #665 ▪   Accessible P Tag Usage (WebAim)
  74. 74. ▪  Must the tooltip of icons match the accessible name? (for "Label in Name", SC 2.5.3) #891 ▪  Are Reflow, Text Size and Orientation cumulative? #391 ▪  What does "support the following text style properties" mean (1.4.12)? #884 ▪  Does using the placeholder with a value alone pass 3.3.2 Labels or Instructions? #864 ▪  Using color ALONE as focus indicator #757 ▪  New SC for keyboard operation? #872
  75. 75. @patrick_h_lauke