Collaboration Tools Accessibility User Requirements

W3C Group Draft Note

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Janina Sajka
(Centre for Accessibility Australia)
GitHub w3c/ctaur (pull requests, new issue, open issues)


This document outlines various accessibility-related user needs, requirements and scenarios for web-based collaboration tools. These typically include one or more specific collaborative features such as real-time content editing by multiple authors, support for comments annotations, and revision control. The Cloud-based office application suites from Google and Microsoft are well-known examples of such collaboration tools.

The accessibility user needs and requirements described in this document may be implemented in the collaboration tool itself, or in an assistive technology application such as a screen reader or screen magnifier. We take a holistic approach to give foremost priority to the user's perspective, leading to the identification of solutions that may be implemented by different components of the software involved in performing a collaborative task.

Although the user needs and requirements identified in this document are non-normative, they may influence the development of future accessibility guidelines, normative technical specifications, or features of collaboration tools and assistive technologies. They are relevant to software developers who contribute to the collaborative experience.

Status of This Document

This section describes the status of this document at the time of its publication. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at

This document was published by the Accessible Platform Architectures Working Group as a Group Draft Note using the Note track.

Group Draft Notes are not endorsed by W3C nor its Members.

This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.

The W3C Patent Policy does not carry any licensing requirements or commitments on this document.

This document is governed by the 12 June 2023 W3C Process Document.

Editor's note

Editor's Note: Contributing to this Document

This updated working draft publication is a document intended to become an Accessible Platform Architectures (APA) Note. The intent of this (and all) APA working draft publications is to gain a wider review of its content and solicit feedback on user needs that may have been missed, underrepresented, or sub-optimally described.

APA encourages review and feedback from all accessibility perspectives to ensure future drafts are as comprehensive as possible.

1. Introduction

1.1 What are collaboration tools?

For the purposes of this document, a collaboration tool is any software that supports features designed to facilitate the interactive creation, editing or annotation of content by multiple contributors, whether working in simultaneous collaboration or asynchronously. Examples of collaboration tools include

1.2 Distinctive features of collaboration tools

This document focuses primarily on features unique to collaboration tools, rather than features which they share with other Web application or with application software in general. Indeed, any tool that provides one or more of the features enumerated here may benefit from the user needs and corresponding requirements elaborated in the sections that follow.

The distinctive capabilities of collaboration tools are illustrated by the examples in section1.1 What are collaboration tools?. It is important to consider how these features are manifested in the tool's user interface. From this perspective, the distinguishing features may be described as follows.

Real-time co-editing
A feature enabling multiple authors to edit the same content simultaneously. The changes introduced by different authors are combined in real time, using algorithms such as operational transformation [concurrency-control]. The combined changes are then made immediately visible in all of the participating authors' editing sessions. The effect is that each author can perceive, in real time, the changes made by collaborators, including the location of another author's focus within the content.
Annotation of content with comments
Some tools enable users to associate comments with parts of the content that is being read or edited. In systems such as word processors, replying to comments is supported, allowing threads of discussion to be associated with parts of a document.
Comparing revisions
Some systems can display the differences between revisions of a text for purposes of comparison.
Suggested changes
Some word processors can show changes (insertions, deletions and formatting-related modifications) made by collaborators, which an author can choose to accept or reject. These revisions are sometimes referred to as suggested changes or as tracked changes. Each change may be accompanied by metadata, for example the identity of the author who made the change, and a time stamp.

Collaboration tools differ widely in the nature of content that may be edited. They also differ widely in the user interfaces presented to users. For example, word processors typically provide a what you see is what you get (wysiwyg) interface based on a rendered view of the content, whereas editors designed for use with source code or markup language text do not. In the latter case, indentation and syntax highlighting may be the only visual cues to the structure of the code or markup available in the editing environment.

We prefer collaboration tools that utilize standard menu organization and typical keyboard commands now well known to users from the stand-alone desktop environment. Standard controls require far less learning from the user, whereas specific accessibility modes with custom keyboard commands, and with menus that shift their location on screen pose significantly steep learning challenges to most users with disabilities, not just users with cognitive and learning disabilities.

Collaboration tools that support editing of graphics, mathematical notation, or other content types are also within the scope of this document. However, only the collaboration-related aspects of such systems are addressed here. The accessibility issues arising from creating and editing these types of content are not considered, as they are separate problems from the user needs associated with the collaborative features of the tools.

Nevertheless it is important that collaborative tools support the full range of editing functions associated with making web content accessible. Among others this would include the ability to add headings, provide alternative text for images and add captions to videos.

1.3 Collaboration tools and accessibility

By following established guidance such as that of Web Content Accessibility Guidelines (WCAG) [wcag22], designers of collaboration tools can help ensure that their user interfaces are perceivable to and operable by a wide range of users with disabilities. However, implementing current guidelines is not sufficient by itself to ensure that such a user interface is understandable, or that it can be used efficiently to complete collaborative tasks. However conforming to WCAG may well be insufficient for collaborative environments. For example WCAG does not inform automated interface simplification control7mdash;a general web accessibility requirement being considered in APA's WAI-Adapt Task Force.

The collaboration features of these tools are necessarily complex. This can impose significant cognitive demands on many users, not only users with specialized accessibility requirements. This is especially true for screen reader users, screen magnification and color contrast assistive technologies, as well as for persons living with various cognitive and learning disabilities. Many users cannot track updates on multiple locations simultaneously, Rather, they necessarily must view and comprehend the interactive elements of the application's features sequentially, for example in speech or braille for screen reader users. A screen reader or magnifier used in a collaborative application may well present suggested changes and comments in one section of the screen while the user is reading a document in a word processor. The user may also be expected to be communicating verbally with fellow collaborators (e.g., in a meeting) while undertaking editing tasks. Moreover, at any time, incoming changes made by collaborators may alter the text that the user is reading or editing in real time.

Due to the cognitive demands created by collaboration tools in the practical and social contexts in which they are used, strategies for improving accessibility are desirable that extend beyond current W3C guidance.

Thus when we talk about collaborative tools we necessarily must consider accessibility burdens imposed by their concomitant complexity. In truth collaborative tools are necessarily complex interfaces for all users, and not only persons with various disabilities. A fairly common example is the use of arbitrary color to flag edits put forth by different collaborators. However, identifying collaborators only by colorization violates WCAG 2.2 Success Criterion 1.4.1 as described below in User Need 11.

2. User need definition

Specific user needs are frequently defined both by task required to achieve a particular goal and also by environmental conditions. Context matters. For example, the cognitive demands imposed by interacting with the collaboration-related features of an application depend not only on the needs and capabilities of the user, including the possible presence of assistive technology, but also on the context. A collaborative task that the user can perform independently while working alone in a distraction-free environment may become cognitively burdensome if performed in a situation such as a meeting. Working with comments and suggested changes in a document may become more cognitively demanding if other authors are simultaneously editing the same content, and the user needs to be aware of their activities (e.g., to avoid introducing conflicting changes) while still performing the editing task. The use of different input types and methods, such as speech input or switch-based input, can affect the amount of time required to enter and edit text, as well as the user's ability to respond to potentially disruptive changes introduced by collaborators.'

3. Real-Time co-editing


WCAG requires that status messages be made available to assistive technologies. See Web Content Accessibility Guidelines (WCAG) 2.2 [wcag22], success criterion 4.1.3, and the associated definition of status message.

4. Annotations


See Web Content Accessibility Guidelines (WCAG) 2.2 [wcag22], success criterion 1.3.1.


REQ 8 may be valuable to users in general, and it should be considered for inclusion as a feature of collaboration tools themselves.

5. Version control features

5.1 Suggested changes

5.2 Presenting Differences Between Revisions

6. Notifications and Messages

Collaboration tools may send notifications to the user for a variety of reasons. For example, a user may be notified if a collaborator asynchronously submits changes to a document or project, or adds a comment. These notifications may be delivered via operating system facilities, or by a messaging service, such as e-mail or an instant message protocol. Moreover, the collaboration tool may support commenting, issue tracking, or other forms of interaction via external messaging. These optional capabilities are addressed in the following user needs and system requirements.

A. References

A.1 Informative references

Concurrency control in groupware systems. Clarence A. Ellis; Simon J. Gibbs. Proceedings of the 1989 ACM SIGMOD international conference on Management of data. 1989.
Web Content Accessibility Guidelines (WCAG) 2.2. Michael Cooper; Andrew Kirkpatrick; Alastair Campbell; Rachael Bradley Montgomery; Charles Adams. W3C. 5 October 2023. W3C Recommendation. URL: