Issue: There are a number of author decisions related to technology use that using UAAG as a baseline doesn't seem to fully address. Should WCAG 2.0 enable authors to requrire support for CSS on their content? If yes, can they claim conformance (at any level) in cases where there content becomes unusable with CSS turned off?
CSS Design principles: (from http://www.w3.org/TR/REC-CSS2/intro.html#q6) provides a potential solution for CSS, but the same issue exists for scripts (see item 4 below):
Complementary to structured documents. Style sheets complement structured documents (e.g., HTML and XML applications), providing stylistic information for the marked-up text. It should be easy to change the style sheet with little or no impact on the markup.
Note: Scripts and applets may provide very useful functionality, not all of which causes accessibility problems. Developers should not consider that the user's ability to turn off scripts is an effective way to improve content accessibility; turning off scripts means losing the benefits they offer. Instead, developers should provide users with finer control over user agent or content behavior known to raise accessibility barriers. The user should only have to turn off scripts as a last resort.
This is a table view generated from the 08 October 2004 Working Draft. It represents a condensed view of the normative sections of the guidelines at various conformance levels and includes notes related to adopting the User Agent Accessibility Guidelines 1.0 as a baseline for WCAG 2.0.
Provide text alternatives for all non-text content.
| Level | Success Criteria | UAAG Notes |
|---|---|---|
| 1 | For all non-text content that is functional, such as graphical links or buttons, text alternatives identify the purpose or function of the non-text content. (text-equiv-functional) | |
| 1 | For all non-text content that is used to convey information, text alternatives convey the same information. (text-equiv-informative) | |
| 1 | For non-text content that is intended to create a specific sensory experience, such as music or visual art, text alternatives identify and describe the non-text content. (text-equiv-sensory) | |
| 1 | For multimedia and time-dependent interactive content, text alternatives identify the content and media alternatives are provided as described in guideline 1.2. (text-equiv-multimedia) | |
| 1 | Non-text content that does not provide information, functionality, sensory experience and is neither multimedia nor time-dependent interactive content, is marked such that it can be ignored by assistive technology. (text-equiv-ignored) | |
| 1 | Any text alternatives provided are explicitly associated with non-text content. (text-equiv-explicit-assoc) | 2.3 Render conditional content (P1) issue: conditional content can also be applied to elements that are not strictly non-text. Need to review UAAG 2.3 item 1a in context of anchor elements, tabular data, etc.) |
| 3 | For multimedia content, a text document (similar to a play script) is provided that includes descriptions of all important visual information as well as transcripts of dialogue and other important sounds. (text-equiv-text-doc) |
Provide synchronized media equivalents for time-dependent presentations.
| Level | Success Criteria | UAAG Notes |
|---|---|---|
| 1 | An audio description of visual events is provided for audio-visual media. (media-equiv-audio-desc) | implementation reports: UAAG Guidelines Not Implemented in Windows Media Player 9 (6 are P1 - other players seem to be in worse shape): |
| 1 | Captions are provided for all significant dialogue and sounds in time-dependent material. (media-equiv-captions) | |
| 1 | Descriptions and captions are synchronized with the events they represent. (media-equiv-sync-captions-descriptions) | |
| 1 | If the Web content is real-time video with audio, real-time captions are provided. (media-equiv-real-time-captions) | |
| 1 | If the Web content is real-time, non-interactive video (for example, a Webcam view of surrounding conditions such as weather information), then one of the following is provided: (media-equiv-non-interactive-equiv) | |
| 1 | If a presentation that contains only audio or only video requires users to respond interactively at specific times during the presentation, then a synchronized equivalent presentation (audio, visual or text) is provided. (media-equiv-interactive-sync-equiv) | |
| 2 | Synchronized captions are provided for all real-time broadcasts. (media-equiv-broadcast-captions) |
Ensure that information, functionality, and structure are separable from presentation.
| Level | Success Criteria | UAAG Notes |
|---|---|---|
| 1 | Structures and relationships within the content can be programmatically determined. (content-structure-separation-programmatic) | UAAG 6.1 and 6.2: Current UA are only able to provide information about some (not all) element users are interacting with. |
| 1 | Emphasis can be programmatically determined. (content-structure-separation-emphasis) | (see above) |
| 1 | Any information presented through color is also available without color (for example, through context or markup or coding that does not depend on color). (content-structure-presentation-color) | Covered by UAAG 6.4, though current support will likely (sometimes) require repair some repair techniques. (ex. Becky's tests on AT support for color information, which indicate that some mechanisms for including color are available to current UA) |
| 2 | Information presented using color is also available without color and without having to interpret markup (for example through context or text coding). (content-presentation-structure-without-color) |
Make it easy to distinguish foreground information from background images or sounds.
| Level | Success Criteria | UAAG Notes |
|---|---|---|
| 1 | Any text that is presented over a background image, color, or text can be programmatically determined. (visual-audio-contrast-determined) | 3.1 Toggle background images (P1) |
| 2 | Text and diagrams that are presented over a background image, color, or text have a contrast greater than X1 where the whiter element is at least Y1 as measured by _____. (visual-audio-contrast-contrast) | |
| 2 | Text that is presented over a background pattern of lines which are within 500% +/- of the stem width of the characters or their serifs must have a contrast between the characters and the lines that is greater than X2, where the whiter element is at least Y2. (visual-audio-contrast-bg-patterns) | |
| 2 | Users can disable background audio that plays automatically on a page so that it does not interfere with text reading software they may be using. (visual-audio-contrast-dis-audio) | |
| 3 | Text is not presented over any background (image, text, color or pattern), or if any background is present, the contrast between the text and the background is greater than X2. (visual-audio-contrast-nobg) | |
| 3 | Audio content does not contain background sounds or the background sounds are at least 20 decibels lower than the foreground audio content, with the exception of occasional sound effects. (visual-audio-contrast-noaudio) | 4.8 Independent volume control (P1) - not well supported. |
Make all functionality operable via a keyboard or a keyboard interface.
| Level | Success Criteria | UAAG Notes |
|---|---|---|
| 1 | All of the functionality of the content, where the functionality or its outcome can be described in a sentence, is operable through a keyboard or keyboard interface. (keyboard-operation-keyboard-operable) | 1.1 Full keyboard access (P1) |
| 2 | Wherever a choice between input device event handlers is available and supported, the more abstract event is used. (keyboard-operation-abstract-events) | 1.2 Activate event handlers (P1) |
| 3 | All functionality of the content is designed to be operated through a keyboard or keyboard interface. (keyboard-operation-all-funcs) | issue: @@ ask UAAG for clarification on this (from 1.1 under rationale) - does this imply that MouseKeys would meet UAAG 1.1?
Suppose a user agent such as a Web browser does not allow complete operation through the keyboard alone. It is still possible to claim conformance for the combination of the user agent and a software component that performs the necessary functions. |
Allow users to control time limits on their reading or interaction unless specific real-time events or rules of competition make such control impossible.
| Level | Success Criteria | UAAG Notes |
|---|---|---|
| 1 | Content is designed so that time limits are not an essential part of interaction, or at least one of the following is true for each time limit: (time-limits-required-behaviors) | 2.4 Allow time-independent interaction (P1)
Issue: Does this conflict with what we have in WCAG 2, which allows for situations where time-independent is not possible? |
| 2 | The user is allowed to turn off content that blinks for more than 3 seconds. (time-limits-blink) | 3.3 Toggle animated or blinking text (P1) Not yet well supported. See also notes under guideline 4.1 regarding <blink> ( 6.3 Programmatic access to non-HTML/XML content (P1) and 2.7-2.10 repair missing content (will require repair techniques) |
| 2 | The user is allowed to pause and/or permanently stop moving or time-based content. (time-limits-pause) | (see above) |
| 3 | The content has been designed in a way that any time limits in the content would pass level 1, success criteria 1 for this guideline without exceptions. (time-limits-no-exceptions) | |
| 3 | Any non-emergency interruptions, such as the availability of updated content, can be postponed and/or suppressed by the user. (time-limits-postponed) |
Allow users to avoid content that could cause photosensitive epileptic seizures.
| Level | Success Criteria | UAAG Notes |
|---|---|---|
| 1 | Content that violates General Flash Threshold or Red Flash Threshold is marked in way that the user can access prior to its appearance. (flicker-rate-and-warning) | 3.2 Toggle audio, video, animated images (P1) 3.3 Toggle animated or blinking text (P1) UAAG has no requirements related to evaluating content for these thresholds. |
| 2 | Content does not violate the General Flash Threshold or Red Flash Threshold. (flicker-does-not-violate) | |
| 3 | Content does not violate any of the Spatial Pattern Thresholds. (flicker-SPT) |
Facilitate the ability of users to orient themselves and move within the content.
| Level | Success Criteria | UAAG Notes |
|---|---|---|
| 2 | In documents greater than 50,000 words or sites larger than 50 perceived pages, at least one of the following is provided. (navigation-mechanisms-minimum-structure) | UAAG 9.9 Allow structured navigation (P2) and 10.4 Provide outline view (P2) - If we were to require structure (similar to 1.3) at level one (per discussion in an Oct. 2004 telecon) would we then need to define "important elements" someplace in WCAG? |
| 2 | Large blocks of material that are repeated on multiple pages, such as navigation menus with more than 8 or more links, can be bypassed by people who use screen readers or who navigate via keyboard or keyboard interface. (navigation-mechanisms-skip) | |
| 3 | Information is provided that would indicate at least one logical sequence in which to read a document. (navigation-mechanisms-one-seq) | |
| 3 | Diagrams are constructed so that they have structure that users can access. (navigation-mechanisms-diagrams) | |
| 3 | Logical tab order has been created. (navigation-mechanisms-logical-tab) | UA tabindex support would require repair techniques. |
| 3 | Each page or other resource that can be accessed separately and that supports a title has a title that identifies the subject or purpose of the resource. (navigation-mechanisms-title) | |
| 3 | There is a statement associated with the content asserting that items from the following list were considered: (navigation-mechanisms-additional-structure) |
Help users avoid mistakes and make it easy to correct them.
| Level | Success Criteria | UAAG Notes |
|---|---|---|
| 2 | If a user error is detected, the error is identified and provided to the user in text (minimize-error-identified) | 1.3 Provide text messages (P1) |
| 2 | If a user error is detected, and suggestions for correction are known and can be provided without jeopardizing security or purpose (for example, test validity), they are provided (in an accessible form that meets Level 1 success criteria). (minimize-error-suggestions) | |
| 2 | Where consequences are significant and time-response is not important, one of the following is true: (minimize-error-reversible) | |
| 3 | Where the input options are known, there are less than 75 of them, and they can be provided without jeopardizing security, test validity, etc, users are allowed to select from a list of options as well as to enter text directly. (minimize-error-selection) | |
| 3 | Checks for misspelled words are applied and correct spellings are suggested when text entry is required. (minimize-error-spelling) |
Ensure that the meaning of content can be determined.
| Level | Success Criteria | UAAG Notes |
|---|---|---|
| 1 | The natural language of the document as a whole can be identified by automated tools. (meaning-doc-lang-id) | |
| 1 | The meaning of abbreviations and acronyms can be programmatically located. (meaning-located) | User agents don't support this well today. - abbreviation/acronym expansion strategies covered in techniques for 2.1 Render content according to specification (P1) |
| 2 | The meanings and pronunciations of all words in the content can be programmatically located. (meaning-prog-located) | Author-specified pronunciation is not yet supported in user agents. |
| 2 | The meaning of all idioms in the content can be programmatically determined. (meaning-idioms) | meet with title for span? RDF reqd.? Other techs? |
| 2 | For each foreign language passage or phrase in the body of the content, the language is identified through markup or other means. Foreign passages or phrases are passages or phrases that are in a language other than the primary language of the document. (meaning-other-lang-id) | |
| 3 | Where a word has multiple meanings and the intended meaning is not the first in the associated dictionary(s), then additional markup or another mechanism is provided for determining the correct meaning. (meaning-multi-meanings) | |
| 3 | Section headings and link text are understandable when read by themselves as a group (for example, in a screen reader's list of links or a table of contents). (meaning-read-alone) | This relates to conditional content issue in UAAG 2.3 (for links). With reliable support for conditional content, the requirment for link text to be understandable out of context may not be needed at all. |
| 3 | There is a statement associated with the content asserting that the Strategies for Reducing the Complexity of Content (the following list) were considered. (meaning-strategies) |
Organize content consistently from "page to page" and make interactive components behave in predictable ways.
| Level | Success Criteria | UAAG Notes |
|---|---|---|
| 1 | Any extreme change of context is implemented in a manner that can be programmatically identified. (consistent-behavior-change-of-context) | 5.3 Manual viewport open only (P2) issue: this is P2 in UAAG and Level 1 in WCAG. issue: are there any ways to cause an extreme change of context that can not be programmatically identified? |
| 2 | Components that are repeated on multiple "pages" within a resource or a section of a resource occur in the same sequence each time they are repeated, for at least one presentation format. (consistent-behavior-consistent-locations) | |
| 2 | All user interface components should be able to receive focus without causing activation. (consistent-behavior-receive-focus) | Covered in 9.5 No events on focus change (P2) |
| 2 | Changing the setting of any input field should not automatically cause an extreme change in context such as leaving the "page." (consistent-behavior-unpredictable-change) | |
| 2 | Interactive elements that appear on multiple "pages," including graphical elements, are associated with the same functionality wherever they appear. (consistent-behavior-consistent-functionality) | |
| 2 | Explicit notice is given in advance of any extreme change of context. (consistent-behavior-unpredictable-warning) | |
| 2 | The destination of each link is identified through words or phrases that either occur in the link or can be programmatically determined. (consistent-behavior-target-identified) | |
| 3 | Graphical components that appear on multiple pages, including graphical links, are associated with the same text equivalents wherever they appear. (consistent-behavior-text-equivalents) | |
| 3 | Components that appear visually on multiple pages, such as navigation bars, search forms, and sections within the main content, are displayed in the same location relative to other content on every page or screen where they appear. (consistent-behavior-visual-location) | |
| 3 | When components such as navigation menus and search forms appear on multiple pages, users can choose to have those elements presented in a different visual position or reading-order. (consistent-behavior-user-choose-order) | |
| 3 | There are no extreme changes of context. (consistent-behavior-no-extreme-changes-context) |
Use technologies according to specification.
| Level | Success Criteria | UAAG Notes |
|---|---|---|
| 1 | Except where the site has documented that a specification was violated for backward compatibility or compatibility with assistive technology, the technology has: (use-spec-document-backward-compat-violations) | 2.1 Render content according to specification (P1) - this is a good example of how WCAG and UAAG are complimentary. 6.3 Programmatic access to non-HTML/XML content (P1) - describes UAAG behavior for out of spec elements. UAAG 8.2 - Conform to specs (P2). This is level 1 in WCAG and priority 2 in UAAG. Though some information about out-of-spec elements (ex. embed, blink, marquee) is available in UAAG test suites, it's not always be clear how user agents should handle out of spec elements. 8.2 also includes specific references to WCAG 1.0 that may need to be updated.
|
| 3 | Technologies are used according to specification without exception. (use-spec-avoid-spec-no-exception) | issue: meeting level 3 here implies that any use of UA repair techniques that recommend specification violations (or bend the rules of how specs were intended to be used) would make it impossible to conform to AAA. |
Ensure that user interfaces are accessible or provide an accessible alternative(s)
| Level | Success Criteria | UAAG Notes |
|---|---|---|
| 1 | At least one plug-in required to access the content conforms to at least the default set of conformance requirements of the User Agent Accessibility Guidelines (UAAG) 1.0 at Level A plus the sets of requirements (a) through (i) (below) that apply. If required plug-ins are not accessible, an alternative solution is provided that conforms to WCAG 2.0. If inaccessible plug-ins are available, then a method for obtaining an accessible plug-in is provided from the content. (technology-supports-access-plugins) | 3.4 Toggle scripts (P1) issue: how does UAAG differentiate plug-ins and other programs from content? are plug-ins considered to be other than content in UAAG?
|
| 1 | Any programmatic user interface components of the content conform to at least the default set of conformance requirements of the UAAG 1.0 at Level A plus the sets of requirements (a) through (i) (below) that apply. If the custom user interfaces cannot be made accessible, an alternative solution is provided that meets WCAG 2.0 (including this provision) to the level claimed. (technology-supports-access-custom-ui) | |
| 2 | Accessibility conventions of the markup or programming language (API's or specific markup) are used. (technology-supports-access-use-access-conventions) | 6.3 Programmatic access to non-HTML/XML content (P1) |
| 3 | The Web resource includes a list of the technologies user agents must support in order for its content to work as intended. The list is documented in metadata if such metadata is supported by the format, otherwise it is documented in a policy statement associated with the content. (technology-supports-access-list-reqd-features) | If UAAG says it must be possible for users to turn off CSS and scripting, then we still have the issue of authors needing to specify which technologies UA must support (and have enabled) in order to successfully interact with their content. Should this criterion be made a higher priority? |
| 3 | Users who do not have one or more of these technologies can still access and use the resource, though the experience may be degraded. (technology-supports-access-test-non-reqd) | If UAAG requires that it is possible to turn off all scripts, should WCAG require that all scripts be (at least) labeled? Should this be addressed here or in 1.1? |
| 3 | Technologies and features on the required list are open standards or have a public specification. (technology-supports-access-ensure-avail) |
The following techniques are links to existing techniques that would be considered repair techniques if we used UAAG as a baseline. A brief explanation for why each item has been identified as a repair technique follows each item.
This list includes existing techniques that fall into the category of repair/bridge techniques. Notes based on discussion at Boston F2F w/ John, David, Tom, Wendy and Ben are included as sub-bullets under the first 15 or so items in the list.