W3C

Overlay Capabilities Inventory

Abstract

Lately various web based accessibility enhancement, remediation, and reporting services have been made available to web content providers under an umbrella term: Overlay. Typically overlays work by adding a snippet of JavaScript into a web content provider's page. This single line of additional code functions to enable additional content processing on each page load delivered through the overlay provider's servers, prior to delivery to the end user. While this routing paradigm is by no means unique to accessibility applications, it does introduce accessibility opportunities and challenges.

In this document we explore the specific capabilities that are, or could be, applied for accessibility purposes whether by overlay technologies, browser extensions, plugins installed on user's devices or by other methods and tools. Some of the capabilities explored here are already available and used in web content delivery systems today. Others suggest best practices guidance. Still others strike us as highly desirable, but will require the creation of a normative W3C specification, especially in the case of cross-platform functionality. As with any web technology, poor design or implementation will predictably yield unsatisfactory user experiences, while well-architected and well-implemented solutions will significantly enhance the user's experience.

Status of this Document

Introduction

What is Meant By Edge?

In this document the term edge technology refers to those web technologies most proximate to the web user that canstill affect the accessibility of assembled (mashed-up) web content. Typically it is:

  1. The user agent (with its user chosen plugins and extensions) together with the host and physical device the user uses to read and interact with web content;
  2. But more powerfully (as we shall soon see), it is the last compositor of content delivered to the user. It is of course cloud-based. And, while it might not be geographically proximate to the user, it functions most powerfully when it functions as the user's proxy agent for organizing web content in the manner the user is best able to use.

Both of these are privileged positions providing access to much information about the user and how the user functions. While we note the need to preserve the web user's privacy here, the remainder of this document focusses on providing accessibility support and assumes privacy is preserved through mechanisms detailed in other W3C technologies.

Automatability

In the Automatability subsection for each capability, we take a pragmatic approach to evaluating the potential for automation, emphasizing the fundamental role of pre-existing technical systems that can detect issues and suggest solutions. These systems utilize algorithms and rules developed from prior experience to predict, assess, and remediate code structures effectively. This process, central to an automation strategy, relies today on thorough human-generated rules and algorithms rather than AI and Machine Learning (ML).

It's essential to clarify that the term autonomous automation does not imply a self-generating or spontaneously adaptive system in this context. Rather, it refers to the capacity to apply these established rules and algorithms across multiple environments predictably. We explore the realistic scope of automation, underscoring that:

This distinction highlights that while AI and ML could eventually enhance the quality and breadth of automation, the core of automatability rests on algorithms explicitly crafted and applied based on extensive human expertise and predictable environmental structures. This approach aligns with the overarching themes of evaluating opportunities and addressing the challenges that new technologies present in enhancing web accessibility.

Web Content Today is Dynamic

In the main the classic paradigm of a web domain owner serving content directly to end users across the Internet has long ago become a historical artifact. Today's typical web page is often a dizzying composite of multiple content streams injected from various sources, including content unique to the user's locale and even to the specific user herself. Content delivered to a user today may be a unique one-off composite that may well change when the page is refreshed. The 2021 Web Almanac notes more than 20 third party injection streams for today's typical web site, with 10% containing over 90 separate content injections.

The source of the typical website today is actually many sources. Even bespoke web applications aren't always created by a single source. Few developers exclusively use their own code. They rely on libraries, components and frameworks to build their web content.

Edge technologies may actually be best placed to help overcome the problem of substandard accessibility in composite content delivered to end users by identifying precisely the accessibility challenges that end users may experience and helping remediate them where it matters most—at the user level, for the simple reason that technology based tracking and reporting can examine far more end user payload deliveries than human testing will ever cover. In particular we consider the role played by various edge-based players beginning with the Content Delivery Network (CDN), the operating system on the user's devices, user-agent, browser extensions, assistive technologies, and/or JavaScript overlays. Whether the resulting remediation is an in-process transformation, or an upstream recoding, gathering and reporting many samples to upstream end points is arguably the most efficient way to spot anomalous patterns (and a great application for A-I analysis).

About This Document

This document describes some capabilities important to web content accessibility that can be provided at the edge, and attempts to answer several questions about them. The questions are:

The capabilities discussed are organized under two primary categories with several subcategories under each primary section. This two-poled approach conforms with client-server architecture, the backbone of all digital transactions and interactions that take place over the Internet. The primary categories are:

The Content Provider, analogous to the server, plays the pivotal role of specifying and delivering diverse forms of digital content ranging from text, images, audio, video, to interactive elements. They curate the experiences that users consume and engage with, thereby shaping the digital landscape. A selection of some primary Content Provider roles:

Role Description
Author Responsible for generating the primary content, be it text, script for audio/video, or conceptual outlines for interactive elements.
Designer Work on the aesthetic aspects of the content including the layout, color scheme, typography, and visual elements. They also handle the user interface and user experience design for interactive content.
Product Owner Oversee the overall content creation and distribution project, make key decisions and coordinate between different teams to ensure the final product meets its intended objectives.
Developer Implement the designs into functional code. They work on the website or application where the content will be hosted, ensuring its responsive, functional, and accessible. Some write proprietary algorithms, but most call and configure frameworks and libraries written by communities of coders.
Marketer Oversee and implement the marketing strategy for the content. They coordinate marketing campaigns and work closely with other teams to ensure the content reaches the desired audience. Growth marketers utilize data-driven marketing techniques to help the business expand its customer base. They use various strategies and tools to attract, engage, and retain users driving critical website requirements.

On the other end of the spectrum is the End User, or the client, who experiences this digital content. End users span a wide range, varying in their demographic, cognitive, and physical attributes. They also bring to the table their unique needs, preferences, and accessibility requirements. It is for these users that content providers shape their digital content and experiences, with or without the knowledge that the user' s own hardware and software may render it in ways the Content Provider never imagined.

Content sites are inherently dynamic; they are assembled for the end-user in a mashup, a unique blend of content that can vary significantly from user to user. A selection of some of the hardware, software, tools and technologies that participate in this edge activity include:

Technology Description
User-Agent (Browser) Interprets and presents web content to the end user. Different browsers may render web content in slightly different ways due to their different rendering engines.
Assistive Technology Devices or software applications that assist individuals with disabilities or impairments. This could include screen readers, alternative input devices, and voice recognition software.
Browser Extension An add-on or plugin that extends the functionality of a web browser. Could alter the appearance of web content, block advertisements, or add additional features to a webpage. Includes mashup tools or web services that combine content from more than one source into a single integrated experience. These can greatly modify the original content and how it is presented to the user.
OS or Software Application A program or group of programs running on the local operating system. Applications can vary drastically in purpose, from productivity apps to entertainment apps, and can influence how digital content is accessed and interacted with.
Video/Audio System Hardware and software components that control the output of video and sound.
Content Delivery Network Store copies of web content in various locations around the world to reduce the physical distance between the server and the user, improving site performance. This intermediary, typically invisible to the end user, plays a critical role in delivery and updating of digital content, as well as authenticating users.

This two-poled digital communication model is not a one-way broadcast, but a dynamic conversation. Feedback from end users can influence and improve the content generated by providers, while content providers continuously adapt their strategies based on user behavior and needs. The feedback loops become more complex as edge technologies come into play.

Glossary

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Content—Usually HTML

This layer of delivered content consists of words, graphics, and rich media objects. In the main it is created using html, both static and dynamic.

Content Editing

Image Alternative Text Provisioning

Supply missing alternative text for content images.

Source
Clearly, alternative text should be supplied by source content. This capability serves as a fundamental accessibility remediation when immediate remediations to the source content are infeasible for some reason.
Trade-offs
Some browser extensions support A-I based alternative text remediation. However, A-I remediation is still considered less accurate, and therefore less desirable than human provided text alternatives.
Benefit
Good alternative text is often essential for comprehending site content for users who cannot see, but also for users on highly restricted bandwidth as continues to exist in many regions of the world.
Automatability
Many cases

Tooltip Provisioning

This capability supplies a small pop-up window that appears on hover to display additional information about an element on the page for users who benefit from enhanced contextualization or clarification.

Source
Source content can, and sometimes does provide this functionality.
Trade-offs
This is not a redundant capability. It is an innovation only available from edge technology in situations where the enhanced content is not intended for all page visitors, but for certain audiences only, such as additional contextualization or clarification for some users living with cognitive or learning disabilities.
Benefit
Supports comprehension for users who require the enhanced support in a manner that does not interfere with the fundamental functionality of the content.
Automatability
Many cases

Site Language Indication

This capability correctly specifies the primary language of a web page when the declaration is incorrect or missing entirely.

Source
Tradeoffs
Benefit
Automatability
Many cases

Title Provisioning

Title Provisioning

This capability provides for meaningful titles, for pages and/or iFrames within pages, and provides screen reader users a more efficient and meaningful browsing experience.

Source
Tradeoffs
Benefit
Automatability
Many cases

User Feedback

Source
Tradeoffs
Benefit
Automatability
Many cases

Content Moderation

This capability helps assure that site content meets the publisher's content policies. Typical policies will include everyday phrases with racist origins, and gendered or exclusive expressions and terms that are deemed to exclude audiences.

Source
Tradeoffs
Benefit
Automatability
Some cases

Video Captioning

This capability provides caption text displaying along with video and synchronized with it.

Source
Source generally provides captions, as they are most knowledgeable about the content.
Trade-offs
The cost of generating captions is prohibitive, promoting the use of automated captions. However, automation often makes mistakes.
Benefit
The cost of generating captions is prohibitive, and automation with human editing is almost universally relied upon.
Automatability
Many cases

PDF Remediation

This capability helps assure that a published PDF document is correctly tagged and marked up sufficiently in order that it can be accessed and more readily understood by people with disabilities, including those who use assistive technology such as a screen reader.

Text Services (Semiotics)

Dictionary On Demand

This capability provides definitions of words or phrases that may be unfamiliar to some users; provides pronunciation guidance; and provides synonyms which can all especially help users living with cognitive and learning disabilities better comprehend content.

Source
While this functionality could be made available through source content, it would be limited to the site that chose to provide the capability.
Trade-offs
The benefit of providing this capability in edge technology is that it can be applied across all sites a user access, and for all devices the user may use. When browsers provide this capability, its functionality is limited to the browser being used (though a particular browser may be able to remember a user's preference for this functionality across multiple devices). Only edge technology can provide this capability across browser and operating environments as well as across sites.
Benefit
Supports comprehension for users who require the enhanced support in a manner that does not interfere with the fundamental functionality of the content. This is yet another instance supporting Configure Once, Use Everywhere.
Automatability
Placeholder pending content

Live Site Translations

Offer a user-triggered method to This capability changes the language of a web page in real time, by translating the current page into a language selected by the user.

Read Content Aloud

This capability allows a user to hear content spoken aloud by using a cloud (or browser) hosted Text to Speech (TTS) engine. There are now high quality TTS engines and listening while reading on screen is often beneficial for users in general, including especially users living with certain cognitive and learning disabilities.

Source
While it could be supported in source content, this capability is rarely (if ever) available in source.
Trade-offs
Users requiring this accommodation will most likely require it across all sites they visit.
Benefit
Only edge technology is capable of performing this accommodation across all sites a user accesses.
Automatability
Placeholder pending content
Related Topics
This capability is yet another example of configure once, use everywhere only available through accessible edge technologies.

Presentation—Usually CSS

The capabilities discussed in this section are afforded users to facilitate content rerendering utilizing presentational characteristics each individual user finds most accomodative. These are accommodations that allow users to perceive and understand published content and serviceslook and feel a content provider may have chosen and published, the user's adaptations must necessarily take precedence for reasons of accessibility. To put it in other words: The author proposes, but the user disposes.

In the main presentation is achieved with css. We have a strong preference for css in presentation rendering because css is most fungible. Rendering the presentation layer through technologies other than css is highly likely to prove inaccessible and require remediation into css in order to support accessibility requirements as defined by W3C.

Cursor & Focus

Capabilities related to enhanced focus visibility Isolating Specific Semantic or Interactive Components for Efficient Browsing and Access: methods and technologies used to enhance user experience by isolating specific elements within a digital interface. It enables users to navigate efficiently through content by focusing on particular types of elements, such as headings or buttons.

Optimize Cursor Size

Some users require a more visible cursor and appreciate the capability that can increase the standard cursor size by up to 400% to ensure the pointer always remains visible to them. This facilitates faster and more accessible navigation through hyperlinks, tabs. and form elements.

Source
It is possible to support this feature in source content directly.
Trade-offs
As with other presentational behaviors described in this document, users who require this capability likely require it across all sites they may use. Thus overlay edge technologies afford the best prospect to meet the need globally.
Benefit
An accessible overlay can provide this functionality across all sites the user accesses. And, when provided via the login-based cloud service, it can do so across the full portfolio of the user's devices.
Automatability
Placeholder pending content

Supply a Reading Guide

Some users benefit from a horizontal line that appears below the text they're reading in order to help them keep their place as they read. This facilitates staying focused.

Source
While it could be supported in source content, this capability is rarely (if ever) available in source.
Trade-offs
Users requiring this accommodation will most likely require it across all sites they visit.
Benefit
Only edge technology is capable of performing this accommodation across all sites a user accesses.
Automatability
Placeholder pending content
Related Topics
This capability is yet another example of configure once, use everywhere only available through accessible edge technologies.

Optimize Hyperlink Visibility

Some people require greater clarity regarding which spans of text or graphics in web content are functioning as hyperlinks. This capability facilitates Selecting the text or image that serves as a hyperlink and causing it to be displayed in a different, more perceivable way, to help users identify the hyperlinks on a page more easily.

Source
By definition this capability is needed because source (as rendered by the browser) isn't sufficiently clear about its hyperlinks, at least for significant user segments.
Trade-offs
Users requiring this accommodation will most likely require it across all sites they visit. While configuring a browser for greater clarity helps, users shouldn't have to configure the same capability across their multiple devices.
Benefit
Only edge technology is capable of performing this accommodation across all sites a user accesses and with all a user's several devices.
Automatability
Placeholder pending content
Related Topics
This capability is yet another example of configure once, use everywhere only available through accessible edge technologies.

Text Styling

Some users require different fonts or different font characteristics in order to comprehend and interact effectively with web content. This section groups those capabilities.

Provide Accessible Fonts

Not all users are able to read any font a web content publisher may choose. This capability allows the publisher' s content to be reformatted in a user chosen font the user is comfortable using

Source
While it could be supported in source content, this capability is rarely (if ever) available in source.
Trade-offs
Users requiring this accommodation will most likely require it across all sites they visit.
Benefit
Only edge technology is capable of performing this accommodation across all sites a user accesses.
Automatability
Placeholder pending content
Related Topics
This capability is yet another example of configure once, use everywhere only available through accessible edge technologies.

Provide Dyslexia Friendly Fonts

This capability differs from Fonts section above only in that the proffered fonts are understood to be particularly usable by people living with dyslexia. Typically, they have more distinctive symbols in order to avoid confusion, increased baselines and thinner tops, and a larger x-height.

Optimize Text Size

Some users need enlarged, or perhaps diminished fonts in order to read content comfortably. This capability allows increased or decrease font size, by supporting clicking an interactive widget in order to make appropriate adjustments.

Source
Source code specifies text size as per the original target audience and design, but only for content coming from that particular source.
Trade-offs
Text size is typically configurable in the operating system. However, not all applications consistently honor the setting and can defeat the user's intent.
Benefit:
Learning how to make such changes in browser and/or operating system configurations is challenging for many, and particularly challenging for the communities that most need it. Offering overlay access raises awareness that such capabilities are present and does not prevent users from learning how to configure it in other places. Overlays are site-specific, making such accommodations on the sites where they are requested. An overlay can propagate such preferences across sites, browsers, operating systems and/or devices, to manage the complete experience including injected and/or dynamic content.
Automatability
Placeholder pending content
Related Topics
This capability is yet another example of configure once, use everywhere only available through accessible edge technologies.

Optimize Text Spacing (Whitespacing)

Some users require additional white-space between lines of text content in order to read comfortably. Others require adjustment between individual characters in and between words. This capability supports these adjustments by facilitating the modification of text and line spacing to support personalized readability enhancement. As typically provided today, the capability offers three degrees of adjustments for a personalized and more accessible reading experience.

Source
Like all aspects of text design, the source determines the experience they think is best for the content.
Trade-offs
May be configurable in the operating system to provide Defaults across all applications on the device—to the extent third party applications honor those settings.
Benefit:
Learning how to make such changes in browser and/or operating system configurations is challenging for many, and particularly challenging for the communities that most need it. Offering overlay access raises awareness that such capabilities are present and does not prevent users from learning how to configure it in other places. Overlays are site-specific, making such accommodations on the sites where they are requested. An overlay can propagate such preferences across sites, browsers, operating systems and/or devices, to manage the complete experience including injected and/or dynamic content.
Automatability
Placeholder pending content
Related Topics
This capability is yet another example of configure once, use everywhere only available through accessible edge technologies.

Optimize Line Height

Some users benefit greatly by simply increasing white space in between lines of text.

Source
While it could be supported in source content, this capability is rarely (if ever) available in source.
Trade-offs
Users requiring this accommodation will most likely require it across all sites they visit.
Benefit
Only edge technology is capable of performing this accommodation across all sites a user accesses.
Automatability
Placeholder pending content
Related Topics
This capability is yet another example of configure once, use everywhere only available through accessible edge technologies.

Margin Management

Paragraph Indentation

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Text Alignment (Justification) Personalization

Fully justified text blocks have long been standard in publishing, including in web content publishing. It is achieved by using variable width fonts and adjusting spacing between characters and words in the block of text. r this practice is not beneficial to all users. This capability allows individual users to determine for themselves the alignment characteristics that best accomodate their reading needs.

Source
While it could be supported in source content, this capability is rarely (if ever) available in source.
Trade-offs
Users requiring this accommodation will most likely require it across all sites they visit.
Benefit
Only edge technology is capable of performing this accommodation across all sites a user accesses.
Automatability
Placeholder pending content
Related Topics
This capability is yet another example of configure once, use everywhere only available through accessible edge technologies.

Images & Graphics

Some users require pixel-level RGB transformations to comprehend and interact effectively with web content. This section groups those capabilities.

Optimize Color Contrast

Color and contrast modifications such as light mode, Dark mode, Inverted Colors, Color Desaturation, and related contrast pigmentation adaptations have proven highly useful to many people with a wide range of visual impairments, and frankly for most users in various distinct situations. They modify the difference between the lightest and darkest parts of a web page, reverse colors, or reduce their intensity.

Trade-offs
This capability is commonly configurable in the operating system itself. Thus edge support needs a compelling reason to diverge from OS defaults. On the other hand, if the user chooses adaptations that could have been set in the OS, it is likely the user is unfamiliar with making these adjustments in their device and should be assisted in doing so—across all their devices.
Benefit
Because most users have similar needs across all their devices and because they tend nowadays to use multiple devices, edge based configuration of this capabilities strongly supports our Configure Once, Use Everywhere principle.
Automatability
Placeholder pending content

Animation Control

Some users require the ability to stop animations or other moving elements on a web page from playing entirely. Others may wish to see them under direct user control, i.e. as a series of steps.

Source
It is possible to support this feature in source, e.g. using CSS Media Queries 5.
Trade-offs
As with other presentational behaviors described in this document, users who require this capability likely require it across all sites they may use. Thus overlay edge technologies afford the best prospect to meet the need globally.
Benefit
An accessible overlay can provide this functionality across all sites the user accesses. And, when provided via the login-based cloud service, it can do so across the full portfolio of the user's devices.
Automatability
Placeholder pending content
Related Topics
This capability is yet another example of configure once, use everywhere only available through accessible edge technologies.

Auto-play Videos

Some users are impeded when media begins playing on page load. Screen reader users may need playback paused until they've assured themselves they've heard all the information their TTS can provide on any given page. Others will seek to enable captions (and possibly even automated language translation) before playback begins. It is also necessary to support a mute function which can be invoked by touch, mouse, keyboard, or other control mapped for such purposes.

Source
It is possible to support this feature in source using native HTML.
Trade-offs
As with other presentational behaviors described in this document, users who require this capability likely require it across all sites they may use. Thus overlay edge technologies afford the best prospect to meet the need globally.
Benefit
An accessible overlay can provide this functionality across all sites the user accesses. And, when provided via the login-based cloud service, it can do so across the full portfolio of the user's devices.
Automatability
Placeholder pending content
Related Topics
This capability is yet another example of configure once, use everywhere only available through accessible edge technologies.

Color

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Accessible Pricing (Strikethroughs)

This capability insures that screen reader users can understand the prior price of an item. Displaying the prior price using strike-through or crossed-out fonts, and then providing the new price immediately next to these does not work for screen reader users. These users will have no idea which is the prior and which the current price without additional content and tagging.

Reset All Personalizations

It is only smart business practice and simple courtesy to support a one button click feature to reset any user triggered enhancement and restore the page to its default state. It should be as easy as possible for users to try different settings and undo them readily. Similarly, it should be just as easy to undo any auto-applied transformations and return a page to the settings provided directly by source. Users should be empowered to adjudge for themselves whether any applied overlay transformation actually enhances their ability to interact—and to return the overlay enhancements should they discover they're actually enhancing their experience, contrary to initial doubt!

Source
This applies to source provided transformations just as much as it applies to edge provided overlay transformations.
Trade-offs
As previously noted some content publishers offer accessibility related page transformation overlays in their source. As also previously noted, the drawback with source provided transformations is that they must be applied over and over, site by site. If indeed a user discovers different settings are needed for different sites, this may appear to argue for not interfering with user chosen settings on a site by site basis. On the other hand, an edge technology—especially one that is associated with a user login—can recognize the distinctions and apply heuristics to learn the nuances a user prefers, possibly enabling it to predict better what might be valuable on a newly visited site.
Benefit
The benefit available only from edge-based transformations is that they can be applied to every site the user visits to achieve consistent results.
Automatability
Placeholder pending content
Related Topics
This capability is yet another example of configure once, use everywhere only available through accessible edge technologies.

Functionality—Usually Javascript

The capabilities discussed in this section are those content publishers must provide users in order to facilitate accessible user interaction with published content and web services. These are described by the fundamentalWCAG principle: operable. In the main they are achieved using javascript.

Structural Semantics Remediation

WCAG explains in painstaking detail the critical importance to accessibility of structural markup. It is a fundamental requirement and any means to remediate or improve missing structural markup provides an immediate functional enhancement to users whose accessibility accommodations rely on explicit structural semantics.

Expose Structural Semantics

Source
It has long been agreed that published content should contain structural markup as provided by HTML and explained by WCAG. Not only is this critical for accessibility, additional processing to further tailor content presentation to particular user needs will rely on proper structural markup, preferably provided by source content.
Trade-offs
There is no inherent value to creating structural markup in edge technology. Doing so is clearly a remedial action to close a critical gap. On the other hand and as previously noted content delivered to end users today is most frequently a composite mashup of multiple input streams and not the simple delivery of content from a single source repository. The very act of mashing together multiple streams introduces a likelihood of semantic incoherency. The very word itself, mashup, strongly suggests a lack of concern for the coherency of the ultimate composite as delivered to the end user. Thus, anything that can be done to introduce greater semantic coherency is of benefit to all users, and especially those users relying on accessibility supporting features such as coherent and explicit structure. Lastly, as also previously noted, emerging strategies to further tailor content interaction to particular user's interaction preferences will rely on good structural markup, and these adaptations will, necessarily, be produced in edge technologies.
Benefit
Whether as a temporary remedial expedient or the advanced personalization adaptation now emerging from W3C accessibility standards, or somewhere in between, users simply deserve the best structural semantics that can be provided them in the moment when they seek to interact with web content. Any and all philosophical should arguments must give way to this simple rubric.

Normalize the Structural Composite

Many users with accessibility needs rely heavily on consistency in the user interface. Yet no standard exists, nor is likely ever to require certain common controls be located consistently across sites. This is very much in the design prerogative of the individual content publisher. And, while individual sites may be fully consistent in where they locate controls on the pages they publish, the user who comparison shops will encounter a different site consistently locating the same controls differently. The publisher has done nothing wrong, but the user is forced to rely on a perfect memory or put up with time-consuming strategies for locating these controls. Consider this example:

  • The user needs to make a reservation on a travel site and will shop several sites to compare offers.
  • Necessarily this involves picking (or specifying) dates.
  • Typically a starting date is specified first.
  • At this point the user needs to locate the control for switching to the specification of the end date.
  • Where is it on this site? Is it at the upper right? The lower left? Some other location on screen on this particular site which is different from other sites the user has searched?
  • Note that that swiping on a touch-screen may easily miss encountering these controls, especially when swiping forward into future dates. Swiping focus will remain in the date-picker widget
  • Searching for these controls risks activating a control irrelevant to the current task such as a notification screen. This further complicates the user's predicament and wastes yet more of the user's time.
Source
By definition this conundrum cannot be resolved by a source content publisher.
Trade-offs
None. Only an edge technology can hope to ameliorate the situation.
Benefit
An edge technology can bring consistency and predictability to the user experience across whatever sites the user may access by locating similar controls similarly.
Automatability
Placeholder pending content

Forms

Form Labels

Forms are the fundamental interface of the interactive web. Programmatic labels for each data entry field or option selecting widget on any form are critical for many users requiring accessibility support. Furthermore, consistent grouping and form controls on screen location is also critical.

Source
Far too many sites fail to use available markup to associate date entry fields and status selection control widgets with the labels the print to screen. These sites expect non-disabled users will simply understand what label applies to what field and widget by virtue of how the two are printed to screen. The user who relies on programmatic association is thus disadvantaged. The problem is amplified by the use and re-use of frameworks and low code forms that lack this support.
Trade-offs
Clearly source should be performing this function. That fact that it is missing from so many sites cries out for remediation technology on the edge.
Benefit
Well built edge technologies can introduce missing programmatic associations. Advanced strategies to sequence completion of complex forms for persons who are easily overwhelmed by on screen complexity are frustrated when these programmatic associations are missing. Furthermore, they are the only technologies that can bring consistent organization to a form.
Automatability
Placeholder pending content
Related Topics
This pervasive problem in interactive content today is also related to Normalize the Structural Composite overlay edge capability described above.

Form Validation

This capability ensures that screen reader users and other users requiring enhanced status support receive clear feedback on the status of a form being completed along with concise error messages. This includes the colors used, the proximity to the form field, and the time-sensitive nature of the screen reader announcement.

Source
Source content can, and sometimes does adequately provide this functionality.
Trade-offs
This is not a redundant capability. It is an innovation only available from edge technology in situations where the enhanced content is not intended for all page visitors, but for certain audiences only, such as screen reader users for some users living with cognitive or learning disabilities.
Benefit
Supports more efficient interaction with forms for users who require the enhanced support. Makes completing forms much easier to accomplish.
Automatability
Placeholder pending content

Client-Side Interactions

Managing Time Outs

Accessible Validation

Client-Side Interactions

ensure keyboard access to interactive elements

Mmanage focus through interactive processes

handle dynamic pages

Managing Time Outs

Accessible Validation

Custom components

correct semantic behavior

apply or adjust ARIA elements

replace component when needed with an accessible version

Textual Affectations

Drop Cap Implementation

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Bulleted and Numbered Lists

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Text Box Framing

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Shadow and Outline Effects

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Text Transparency Control

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Interactive Text Elements

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Notifications

Messages shown to the end-user to alert them to an event, some specific data-point, or to some state.

Source
It seems unlikely source could fully take on this responsibility. On the other hand it seems equally unlikely that edge technology alone can fully meet this need effectively without API-based data interchange with source content. There is particularly cogent needs in augmented reality which are potentially very exciting.
Trade-offs
What a user may want or need to know in any given situation or moment is a complex calculation at best. It' s far too easy to overdo notifications, though failing to notify judiciously and appropriately would constitute a major technological opportunity missed. We need better models and privacy-preserving context awareness to realize all the benefits conceivable in this application of automated opportunities.
Benefit
Controlling the fire hose of notifications is best filtered and managed at the edge because that's the most data rich locus for technology mediated adaptation and minimal data round-trips to servers. The right information at just the right time can serve as a tremendous quality of life enhancement and it's best performed locally, not centrally.
Automatability
Placeholder pending content

Authentication

Rich Media

Include hyperlink to MAUR

Voice Command

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Management

The capabilities discussed in this section are primarily of interest to the content provider who shape the key elements or features of their digital content in order to support an intended user persona and journey. As stated above this typically results in a highly interactive experience presented to the user, packed with services supplied by third parties, many of which are added in their efforts to further accommodate, engage and please the end user while meeting regulatory requirements.

Leveraging Automation

Having Sufficient Knowledge & Skills

Accessibility is a complex subject, and approaches differ per role. Suitably trained designers, brand owners, marketing managers, software developers and quality assurance are difficult to hire and retain.

Source
The most accessible organizations are those with a deep and robust culture around accessibility. Every role is aware and trained in the topic. In addition, persons with disabilities are involved as well.
Trade-offs
Offloading accessibility knowledge may mean the organization will never reach the attitude and approach expected as a low bar of accessibility: including people with disabilities.
Benefit
Like any complex topic, organizations are wide to hire experts and give them the latitude to fix things. Since providing access to digital assets at source is a security risk, allowing the accessibility provider to fix things at the edge is a sound decision.
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Related Topics
Knowledge and skills are a primary driver behind My Site, Their Service.

My Site, Their Service

Third party services not hosted by the Content Provider, providing services in support of the Content Provider's value proposition. Typically invoked by JavaScript or the Content Delivery Network, they meet the planned needs of end users.

Source
They typical website today is a platform for interaction, a space where an organization meets its customers. End users expect a broad range of services that are likely outside the core competency of the site owner. A company cannot become jack-of-all-trades and master of none. Build or buy decisions, when executed well, can mean the difference between success of failure for a business. Just as most companies don't build the buildings they inhabit or the elevators that operate within, they do not program the intricate digital services required on their websites such as GDPR cookie handling, chatbots, or shopping carts. Procurement can request accessibility conformance statements from services as a gating decision point to include them on the page or not.
Trade-offs
Companies relinquish some control when they host functions via third parties. But their responsibility is to verify the accessibility of these services.
Benefit
Given the bewildering range of possible experiences with all these third party plugins operating, the edge becomes the only place where a proper validation can occur.
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Related Topics
This is closely related to Having Knowledge and Skills and Only The Edge Knows For Sure.

Only The Edge Knows For Sure

While some rare web pages serve up a single experience like a short order cook handing over a burger, most are like the food court at a shopping mall with many independent services rallying to the end user's needs. Content providers pack their pages with services such as cookie permissions, chat, payment gateways, user-generated reviews, and most prolifically advertisements.

Source
Content providers can only guess at an end user's experience by testing well chosen scenarios. Large organizations may arrange focus groups that give a glimpse of a few users, at one moment in time. But in the end, almost by definition, the source cannot know.
Trade-offs
Persons with disabilities tend to be concerned about content providers discovering and monetizing user data. Their lived reality has made them highly desirous to preserve their privacy because of perceived and actual experience of discrimination over many years. Privacy assurances, along with steep privacy violation fines, can build trust over time, such as that supporting the nearly ubiquitous use of Google Analytics at the edge.
Benefit
Sampling and monitoring the accessibility of the user experience can only occur at the moment of user access because only the edge knows for sure. Much as a thermostat should be positioned far from the heat source, to measure the temperature of the room, monitoring at the edge is the only way to determine what is happening there.
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The uniqueness of the Edge experience is driven primarily by Only The Edge Knows For Sure (3.1.3). Any listening in on the Edge will have to Preserve User Agency (2.1.1).

Fully Automated Transformations

Automated transformations applied based on conditions edge technology discovers in the user's technology.

Source
Content providers have long sought to tailor UX behavior based on what capabilities could be discovered about the user's operating environment. What browser is in use? Desktop, mobile or smart watch? Is a screen reader in use? Indeed, Google's automated Recaptcha 3 is deeply dependent on just such data gathering.
Trade-offs
While a well-crafted remediation technology may be invisible to users, it is both risky and presumptuous to presume there will be no users who will not experience some kind of accessibility challenge even among the best crafted remediation technologies. Matters are made worse when the user is left uninformed and feels a loss of agency.
Benefit
Users do indeed expect their technologies will operate automatically and seamlessly to provide an accessible and functional experience. This is an accepted technological expectation. Content providers do not err in attempting to meet this expectation. An automated UX transformation approach can provide clear benefits. One example is real-time applications such as Real Time Communications (RTC). Immediacy matters. Automated captions may not provide the desired quality, but the alternative may too often be no captions whatsoever. Similarly missing image descriptions generated by A-I may prove more helpful to the user coping with a substandard page than no alternative text at all. Pages whose content remains unremediated can also tend to encourage users to seek alternative providers.
Automatability
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Related Topics
Keep in mind that Only The Edge Knows For Sure. We emphasize the critical importance of Preserving User Agency in fully automated transformations.

Automated Detection and Remediation of WCAG Violations

Algorithmic detection of violations of WCAG 2.x success criteria is considered here as a vector for providing the user a more conformant experience. There is, of course, the other application, where violation detection serves as a step in a source remediation process. We address the former here.

Source
If source got this right (as WCAG 2.x seems to expect), we wouldn't have a need for this capability.
Trade-offs
In-browser scanners and online scanners are used to detect WCAG violations. This is the business model for many companies. False positives, false negatives, certainty and confidence scores are well-known factors affecting the success and usefulness of this approach. It is unfortunate when such violations remain unremediated in source content, but sometimes this can't be helped. An indication of violations at the edge, however rough, is better than none.
Benefit
Large, complex and highly dynamic source sites are literally unable to reproduce every user experience permutation in their test beds. Automated detection and reporting can help bridge this gap. Something is most often better than nothing, especially in the moment. It looms ever larger as it stacks, and automated detection is often the first step in a chain of capabilities.
Automatability
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Related Topics
Keep in mind that Having Knowledge and Skills, as well as Only The Edge Knows For Sure and .

Human Mediated Automated Remediation

While not the glamorous holy grail of technology deployment today, human mediation of A-I identified checkpoints, together with the site owner's active participation to clarify meaning and intent, describes an effective approach to accomplish accessibility remediations where they're needed. No other approach delivers equally effective remediations at such scale.

Source
This is a process approach just as meaningful for remediating accessibility violations in source as it is for remediating at the edge. Though to argue any remediation not done at source or not performed by a human, may describe a theology of accessibility, not a technological solution delivering real benefits to users.
Trade-offs
It is clearly preferable to remediate violations in source content whenever doing so is feasible. An in-process corrective overlay remediations only make sense when there are good reasons why the source cannot be remediated.
Benefit
The user always benefits when best available remediation approaches are employed. Nor will the user ever care where and how the remediation is accomplished as long as it facilitates the user' s ability to function.
Automatability
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Accessibility Editing, By Site Owner

This capability describes an interface in the overlay, available to authorized users, facilitating manual editing of source code that affects accessibility, e.g. alt tags for images, or ARIA labels, often with the assistance of linting, wizards and supplemental materials.

Source
Where the source lacks sufficient accessibility supporting markup, this capability provides both analytics and remediation access to properly authenticated persons empowered to perform remediation. Note the assumption is that, for whatever reason, the content technology provided by the hosting environment lacks adequate accessibility supporting technology.
Trade-offs
A properly configured content hosting environment should be able to accomplish accessible content publication. Such editing performed at the edge depends on robust IDs, and can be more brittle than changes at source.
Benefit
This capability facilitates adding missing accessibility supporting markup to source content. It is unique to overlays of this type, providing an alternative to standard methods of coding the site, either via source code, web platform templates/CSS adjustments, etc. This capability exists to assist sites who fail accessibility, usually for a complex set of reasons where source remediation is expensive or otherwise not readily achievable. This is not a redundant capability. Rather, it is an innovation only available from edge technology. Equivalent technology in source would require the site publisher to establish a complete panoply of content management tooling. While this is certainly feasible, not everyone wishing to make content available on line desires to spend time gaining proficiency with content management systems.
Related Topics
This editing typically requires accessibility expertise, but the content publisher's expertise, and the site's content may actually represent an entirely different area of content expertise.

Accessibility Editing, By 3rd Party

This capability functions very much like the Accessibility editing, by site owner immediately above, except that a third party accessibility coding expert is granted access to perform needed remediations.

Source
The only alternative in source is write access for the third party to the source content. On some sites this may require full administrative access.
Trade-offs
This is not a redundant capability. It is an innovation only available from edge technology.
Benefit
Accessibility edits are provided to the content publisher much like pull requests in version control systems.
Automatability
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Content Provider Checks

Feature-Bundling Profiles

Site publishers need to support the full spectrum of accessibility features. On the other hand individual users need certain features and will ignore those they do not need. The types of features individual users need are often group-able into bundles, making it easier to turn on groups of features, e.g. high contrast and larger text size.

Source
As previously noted, users will need the same (or very similar) feature support across all their various devices. This makes supporting even grouped feature profiles in source (and even in the OS) less effective than an edge solution could be, because it requires the user to make the same selections time and again.
Trade-offs
Grouping related features together into named profiles enables users to find and focus on the ones they need to configure and ignore the rest. The emerging approach aimed at propagating user profile configurations across all of a user's devices makes edge technology the only logical locus for this capability.
Benefit
This is yet another instance supporting Configure Once, Use Everywhere.
Automatability
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Accessibility Statement Availability

Providing an easily located Accessibility Statement has become a widely accepted best practice in the industry. While there is no consensus on what all should be included, it is generally agreed that the formal Statement should define the site's commitment to accessibility of its content and services. Additional content, such as accessibility specific contact data, and accessibility specific help resources are also frequently included.

Source
It is currently a best practice to link to the Accessibility Statement (and related resources) from the site's footer.
Trade-offs
An Accessibility Statement introduced by edge technologies doesn't add value, though adding locale specific content might be useful.
Benefit
To the extent that locale specific data may be helpful to users, edge technology may be the best means of providing the most timely locale-specific accessibility information.
Automatability
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Accessibility Provider Identification

This capability displays to website users the name (and perhaps the logo) of the primary accessibility provider, who stands behind the accessibility of the site. This may be part of the accessibility statement.

Source
Identifying the provider of accessibility to site source is a matter of transparency and will likely be gladly accomplished by any provider taking pride in the quality of their output.
Trade-offs
Providing accessibility to content, whether at the source or with in-process transformations, should never be opaque. Users deserve to know who is responsible for their experience of web content.
Benefit
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Accessibility Issue Reporting

This capability provides a form, or an email link, enabling end-users the ability to report barriers they've experienced on a site. Accessibility-specific reporting is an industry best practice.

Source
Clearly, such a form-based reporting mechanism can be in source content. It is another feature that would likely be best provided along with the Accessibility Statement and related resources.
Trade-offs
While not obviating source based issue reporting, edge technologies are uniquely positioned to attach possibly relevant metadata to such reports.
Benefit
Such a form requires the source provider to think through who should receive and process these reports. Most particularly, they will need to consider what accessibility expertise is available to evaluate and follow-up on such reports.
Automatability
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Aspirational

The capabilities discussed in this section are aspirational because they describe development directions we believe edge technologies will take in the coming decade. They will rely on various specifications from the W3C around authentication, security, and privacy in addition to developments in W3C accessibility technologies.

Personalized & Portable Configuration Profiles

Configure Once, Use Everywhere

Users now frequently use several devices. Furthermore, users tend to have the same or very similar accessibility requirements regardless of the device they may be using in the moment. It is therefore an emerging goal in web accommodations to support the user in configuring once and having their configured preference propagate across all their devices. Such a cross-Device preference profile should ideally function across all vendors and operating environments.

Source
While technically feasible in source, this is not being done by content source today, and we are not aware of any proposals to add such functionality in content source—likely for a multiplicity of reasons. People, regardless of ability or disability, may often want to withhold this information from a source provider, and would certainly not want it to propagate to source providers outside of their knowledge or control.
Trade-offs
A privacy-preserving, cross-platform U-I configuring capability is now a long-term goal in the W3C Accessible Platform Architectures (APA) Working Group. Such a capability has long been desired and is arguably now more achievable than ever before. It would clearly be valuable to users. For example, blind users and people on slow internet connections will benefit from setting their browsers to not download images. It will nevertheless require nuanced implementation, e.g. screen size and consequent decisions over preferred fonts, spacing, and contrasts will likely vary by screen size and environmental conditions. Another example of a nuanced consideration is the likely desire of a screen reader user to operate sometimes with TTS, but other times with braille (or both braille and TTS).
Benefit
Configure once and deploy everywhere, with the setting propagating to other contexts would constitute a profound efficiency enhancement for users. We note this is already being realized by technology vendors within their own operating environments, but we believe users should be supported even when they mix and match devices across operating environments.
Related Topics
While this capability remains aspirational in the main as of this writing, it is nevertheless an achievable goal for which edge technology is optimally suited. Many other capabilities enumerated in this document will point to this capability as an optimal implementation objective.
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Surrogacy Support

A compelling largely unmet need exists for legal surrogacy services, whether fiduciary, medical, or probate. Whether to access data stored in the account of someone recently deceased, or in the account of a minor child, or of a parent or social agency client, only a very few major web content service providers have begun addressing this need as of this writing and only for their own systems. This need is particularly acute where print disabilities are to be factored. Most legal jurisdictions today accept such instruments executed only on paper, thus discriminating against persons incapable of managing paper on their own. When provided for persons with disabilities this capability is today increasingly known as Supported Decision Making (SDM), and has historically also been known as Guardianship.

Source
While it could be supported in source content, this capability is rarely (if ever) available in source.
Trade-offs
Users requiring this accommodation will most likely require it across all sites they visit.
Benefit
Only edge technology is capable of performing this accommodation across all sites a user accesses.
Automatability
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Related Topics
This capability is yet another example of configure once, use everywhere only available through accessible edge technologies.

Normalize Control & Content Layout

File Format Translation

Document format translation is important for most serious users of software, but arguably more so for the user relying on assistive technologies.

Source
While it could be supported in source content, this capability is rarely (if ever) available in source.
Trade-offs
Users requiring this accommodation will most likely require it across all sites they visit.
Benefit
Only edge technology is capable of performing this accommodation across all sites a user accesses.
Automatability
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Calendar Format Translation

Calendar format translation is important for most any user of software, but arguably more so for the user relying on assistive technologies. While industry could long ago have solved this persistent incompatibility across operating environments, they have rather chosen to seek to impose vendor lock-in. This does not serve users who should be free to maintain calendars in the environment of their choice, or even different calendars in multiple environments with full transparency. This is not a technical challenge. Rather, it is a business choice.

Source
While it could be supported in source content, this capability is rarely (if ever) available in source, and then only in third party applications seeking to support all common calendaring formats. In fact this capability illustrates source intransigence where user needs should predominate.
Trade-offs
Users requiring this accommodation will most certainly require it across all sites they visit.
Benefit
Only edge technology is capable of performing this accommodation across all sites a user accesses.
Automatability
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Related Topics
This capability is yet another example of configure once, use everywhere only available through accessible edge technologies.

Support Command Normalization

Sometimes vendors support accessibility by mapping a series of keystrokes for screen reader users (and others who prefer keyboard commands to mouse clicks) to their own proprietary definitions. Often these duplicate standard command sequences used for similar purposes in widely used software. This capability proposes that overlay technology can remap proprietary command mappings to more commonly known command mappings, thus greatly reducing or even eliminating an unnecessary learning challenge for the end user.

Source
While it could be supported in source content, this capability is rarely (if ever) available in source.
Trade-offs
Users requiring this accommodation will most likely require it across all sites they visit.
Benefit
Only edge technology is capable of performing this accommodation across all sites a user accesses.
Automatability
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Related Topics
This capability is yet another example of configure once, use everywhere only available through accessible edge technologies.

Mediate Content Skimming

It is often useful to skim through content to determine what, if any of it, might benefit the user by a more careful reading. Good user agent support for such a feature would not only support sequential summarization, but the marking of particular sections to return to for greater study.

Source
While it could be supported in source content, this capability is rarely (if ever) available in source.
Trade-offs
Users requiring this accommodation will most likely require it across all sites they visit.
Benefit
Only edge technology is capable of performing this accommodation across all sites a user accesses.
Automatability
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Related Topics
This capability is yet another example of configure once, use everywhere only available through accessible edge technologies.

Mediate Skimming Sign-Language Content

Skimming through content to determine what, if any of it, might benefit the user by a more careful reading is just as valuable to users who depend on sign-language, or who utilize Augmentative and Alternative Communication (AAC) symbolic languages, as it for those who read text. As with summation services with text, good user agent support for such a feature would not only support sequential summarization, but the marking of particular sections to return to for greater study.

Source
While it could be supported in source content, this capability is rarely (if ever) available in source.
Trade-offs
Users requiring this accommodation will most likely require it across all sites they visit.
Benefit
Only edge technology is capable of performing this accommodation across all sites a user accesses.
Automatability
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Related Topics
This capability is yet another example of configure once, use everywhere only available through accessible edge technologies.

Appendices

Design Principles

Our approach to the design and analysis in this document is rooted in the principles often called: Human-Centered Design (HCD). As an outlook that places people at its core, we believe HCD aligns perfectly with the goals of accessibility. This method of design prioritizes empathy, collaboration, and user empowerment, which aligns with our mission to generate accessibility solutions that meet the diverse needs of various human individuals. Our understanding of HCG requires us to minimize technological configuration tasks and maximize each individual's ability to read and interact with actual content—not the application (or browser) chrome.

Among various design terminologies linked with accessibility such as universal design and inclusive design, HCD sets itself apart due to some specific distinct attributes, such as:

Our design philosophy does not merely aim for inclusivity; instead, it strives to create meaningful experiences that significantly enhance the lives of the people we serve. A successful application of HCD manifests not just in broad-reaching accessibility, but in generating rich, meaningful, and transformative experiences for the user.

Furthermore, HCD endeavors to build a comprehensive understanding of the end user, transcending the confines of mere accessibility. It delves into the emotional, cognitive, and social dimensions of the human experience, with a commitment to design solutions that resonate on a profoundly personal level.

Our commitment to HCD is woven throughout our efforts to ensure accessibility. In prioritizing a user's individual needs and emphasizing their active involvement in the design process, we believe we can create a more accessible and inclusive digital environment. By employing HCD, we hope to deliver a seamless, enjoyable experience for all users, that is more than just accessible - it is truly human-centered.

User-triggered Transformations

User can be afforded the opportunity to opt-in to various transformations via interactive personalization menus: The end-user can access a list of available enhancements and enable those they require.

Source
Users tend to require the same types of accommodations across all sites and all content sources. Therefore, facilitating this capability in the source is likely the least useful place to locate it, because that would require the user to select the same enhancements time and again across the succession of sites visited and likely with different menu organization site to site.
Trade-offs
Many of the capabilities made available by user-triggered opt-ins are often also found in multiple places at the edge. For example, contrast adjustment is generally found in operating system display settings, in browser and app user-agents (e.g. dark mode/light mode), and in browser extensions, and in JavaScripted (CDN hosted) overlays. Such redundancy can easily lead to confusion. This confusion may be further exacerbated because certain settings the user finds helpful may be available only in one of these locations, and not in all of them. Furthermore, users are frequently not particularly knowledgeable about their operating system settings menus, especially as these tend to move with each OS revision (to take one example). This can make it difficult to locate these features, especially when we recognize that once satisfactorily configured they are generally not reset (meaning that the user doesn't need to revisit that menu location and soon forgets where it is). On the other hand, locating the accommodation consistently proximate to the user offers the highest likelihood of maximal benefit provided the accommodation can be easily identified and invoked. This also provides the best opportunity for easing the burden of invoking the same accommodation across a user's multiple devices.
Benefit
Users can select and optimally tune the types of accommodations that they require. Any device on the edge may also have knowledge of other devices on the edge, that may need the same adjustments, and edge technology could propagate these settings to those other devices. MacOS Ventura (MacOS 13.2) is already doing this for Wi-Fi passwords when an IOS device configured for the same network is proximate.
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Acknowledgments

Participants of the A11yEdge Community Group who contributed to the development of this document: