Model-Based UI Working Group Charter

The mission of the Model-Based UI Working Group, part of the Ubiquitous Web Applications Activity, is to develop standards as a basis for interoperability across authoring tools for context aware user interfaces for Web-based interactive applications.

Join the Model-Based UI Working Group.

End date 30 November 2013
Confidentiality Proceedings are public
Initial Chair Gerrit Meixner, DFKI
Initial Team Contacts
Dave Raggett (0.2 FTE)
Usual Meeting Schedule Teleconferences: Weekly
Face-to-face: 1-3 face to face (F2F) meetings are planned per year, but the chairs have the prerogative to call additional meetings if the work requires or decide not to call a F2F if budget or timing requirements make it difficult to organize.


Application developers face increasing difficulties due to wide variations in device capabilities, in the details of the standards they support, the need to support assistive technologies for accessibility, the demand for richer user interfaces, the suites of programming languages and libraries, and the need to contain costs and meet challenging schedules during the development and maintenance of applications.

The market for authoring tools for Web applications and interactive application front ends in general remains under developed. In many cases, the tools that exist rely on proprietary formats, or APIs specific to particular programming languages, and this hinders developers from switching between tools, and this is increasingly a concern in a number of industries, e.g. aviation and automotive. The emergence of popular libraries such as jQuery demonstrate the importance of reducing the burden on developers, and the need to decouple the effort required to work on different aspects of design and implementation of interactive application front ends. If you are focusing on the usability or styling of a user interface, you shouldn't need to deal with the lower level details of how this will be realized on a given device or platform.

This Working Group draws upon many years of research into model-based design, and continues the work started in the Model-Based UI Incubator Group, the associated W3C Workshop in Rome, and a follow up meeting at the W3C Technical Plenary 2010:

Compatibility and Deployment Expectation

The Model-Based UI Working Group will benefit from extensive experience with model-based user interface design solutions, and will provide a strong basis for interoperable authoring tools for interactive application front ends, with HTML5 as a key delivery platform. The Web is increasingly seen as a platform for distributed applications, and the MBUI WG specifications are expected to be widely utilized as a basis for reducing the cost and increasing the productivity of application user interface designers as well as application developers.


Use cases and Requirements
As needed to guide and justify the design decisions for the development of the specifications.
Specification of meta-models for interchange of models between authoring tools for (context aware) user interfaces for web-based interactive application front ends
This could take the form of UML diagrams and OWL ontologies, and cover the various levels of abstraction (e.g. as defined in the Cameleon reference framework, as well as that needed to support dynamic adaption to changes in the context).
Specification of a markup language and API which realize the meta-models.
This is expected to draw upon existing work such as (but not restricted to) Concur Task Trees (CTT), Useware Markup Language (useML), UsiXML or UIML.
Test assertions and Test suite for demonstrating interoperability
This is needed to support progress along the W3C Recommendation Track, and in particular, to exit from the Candidate Recommendation phase.
Model-based user interface design primer
An explanation/guideline for how to apply the specifications to support the development of the associated use cases.
Open Source Implementations
Working Group members may wish to develop open source implementations of authoring tools to demonstrate the potential, and for use in developing and applying the test suite described above.

Out of Scope

Some features are explicitly out of scope for the Working Group

Defining markup and APIs for direct interpretation by interactive application front ends (e.g. web browsers).
But where appropriate, it should be feasible to define markup, events and APIs that are supported by libraries, e.g. JavaScript modules. This may be needed to support dynamic adaptation to changes in the context.


The Working Group will develop specifications for two W3C Recommendations, together with W3C Working Group Notes for associated non REC track deliverables. Open source implementations may be released to accompany the specifications.


Note: The group will document significant changes from this initial schedule on the group home page.
Specification FPWD LC CR PR Rec
Meta-Models for Context Aware interactive application Front Ends March 2012 September 2012 February 2013 June 2013 August 2013
Markup Language and API for MBUI March 2012 September 2012 February 2013 June 2013 August 2013

Timeline View Summary

Dependencies and Liaisons

W3C Groups and Specifications

CSS Working Group
Style sheets for Web applications. This is relevant to "skinning" concrete user interface designs, and also to the means to adapt styling to match device capabilities through CSS media queries. The MBUI WG could review proposed CSS3 modules for their fit for the needs for a range of UI designs.
Device API's Working Group
Defining client-side APIs for applications to interact with devices services such as Calendar, Contacts, Camera, etc. The DAP WG is also expected to consider work on APIs for local discovery that could be valuable for context aware applications.
Geolocation Working Group
API for determining the location and orientiation of a device, and therefore relevant to location aware user interfaces.
HTML Working Group
HTML5 is an important delivery target for the Model-Based UI Working Group.
Internationalization Core Working Group
Ensuring that W3C specifications are fit for use with different languages, scripts, and cultures. In the context of UI design, a key consideration is enabling designers to support localization
Multimodal Interaction Working Group
Specifications relating to multimodal interaction, including interpretations of user input (EMMA), ink traces from touch and pen input (InkML), the representation of emotions and related states as part of user interaction (EmotionML). The related HTML Speech Incubator Group focuses on integrating speech technology in HTML5 to provide a browser-independent multimodal experience. The MBUI WG should ensure that the proposal meta-models enable the design of multimodal user interfaces.
Real-Time Communications Working Group
This is a proposed W3C Working Group that would focus on specifications for interactive real-time communications, including the establishment of peer to peer connections.
SVG Working Group
Scalable vector graphics that can be animated and scripted as part of the user interface for Web applications. SVG provides a target for model-based UI design on its own or in conjunction with HTML.
UWA Delivery Context Ontology
Provides a formal model of the characteristics of the environment in which devices interact with the Web or other services. The Delivery Context includes the characteristics of the Device, the software used to access the service and the Network providing the connection among others. The Delivery Context is an important source of information that can be exploited to create context-aware applications, thus providing a compelling user experience.
Voice Browser Working Group
Specifications for human-computer interaction via speech. These provide a target for model-based UI design.
The Accessible Rich Internet Applications Suite, defines a way to make Web content and Web applications more accessible to people with disabilities. It especially helps with dynamic content and advanced user interface controls developed with Ajax, HTML, JavaScript, and related technologies. Model-Based UI design should simplify the generation of ARIA enabled applications.
The Protocols and Formats Working Group assists other W3C groups with reviews of proposed specifications to ensure that W3C specifications provide support for accessibility to people with disabilities. The MBUI WG would seek review from WAI-PF to ensure that the model-based UI design specifications take accessibility into account for both designers and end-users.
Web Applications Working Group
Covering a variety of APIs and mechanisms for use by Web applications, e.g. offline operation, background scripts, cross docuument messaging and remote events. Together, these provide rich possibilities for targeting model-based UI.
Web Events Working Group
Chartered to develop specifications for physical multitouch interface events (including such related interface as pen-tablets, electronic whiteboards, and similar input devices), as well as for higher-level events which encapsulate touch interfaces, keyboard input, mouse control, and other input devices, into a single simple, consistent model that defines user actions (such as zoom-in, scroll, redo, undo, and so forth). The Web Events Working Group will consider four conceptual layers for interaction: physical, gestural, representational and intentional. This will be of direct benefit to the Model-Based UI Working Group, and close cooperation is expected between the two groups.
Web Notifications Working Group
Defining an API for displaying simple notifications to the user. This is potentially relevant as a means for alerting users to changes to the context, thereby inviting users to request changes to the UI.

External Groups

A European FP7 research project aimed at developing a novel, open platform for enabling the creation of context-sensitive service front-ends that react to changes in the context, adapting the UI to a person's devices, tasks, preferences, and abilities. The MBUI WG should establish close links with Serenoa to benefit from the research perspective and experience with model-based UI design and delivery to a variety of contexts and modalities.
A European FP7 research project aiming to deliver a platform for web applications across mobile, PC, home media (TV) and in-car devices. The webinos project will define and deliver an Open Source Platform and software components for the Future Internet in the form of web runtime extensions, to enable web based applications and services to be used and shared consistently and securely over a broad spectrum of converged and connected devices, including mobile, PC, home media (TV) and in-car units. The MBUI WG should liaise with webinos to benefit from the use cases and platform design work being done by webinos.
The MARIA Environment provides a novel solution able to exploit task models represented in the ConcurTaskTrees (CTT) notation and user interface models (in the MARIA language) for the design and development of interactive applications based on Web services for various types of platforms (desktop, smartphones, vocal, and multimodal, etc.).
Morpheo MyMobileWeb
An open source, standards-based software framework that simplifies the rapid development of mobile web applications and portals. MyMobileWeb encompasses a set of technologies which enable the automatic adaptation of applications to the target Delivery Context (browser, device, network, and location, etc.).
UsiXML (which stands for USer Interface eXtensible Markup Language) is a XML-compliant markup language that describes the UI for multiple contexts of use such as Character User Interfaces (CUIs), Graphical User Interfaces (GUIs), Auditory User Interfaces, and Multimodal User Interfaces.
ANSI/CEA-2018 defines a task model description language aimed at the user interfaces for consumer electronic devices. The MBUI WG should clarify the positioning and scope of its work with respect to ANSI/CEA-2018.
The purpose of the OASIS UIML Specification TC is to develop a specification for an abstract meta-language that can provide a canonical XML representation of any user interface (UI). The language should be capable of specifying the requirements, design, and implementation of any UI.
The project automotiveHMI is funded by the German Federal Ministry of Economics and Technology and aims to improve the process of the development of user interfaces in the automotive domain. An integrating approach based on standardized languages, models and interfaces leads to an improvement of efficiency for all companies involved from car manufacturers and component suppliers to the producers of the used tools. The description based on abstract models also enables the convergence of new, multi-media and multimodal forms of interaction in completely new operating systems. The MBUI WG should establish close links with automotiveHMI to benefit from the research perspective and experience with model-based UI design and delivery to a variety of automotive platforms.


To be successful, the Model-Based UI Working Group is expected to have 8 or more active participants for its duration. Effective participation in the Working Group is expected to consume one work day per week for each participant; and up to two days per week for editors. The Model-Based UI Working Group will allocate also the necessary resources for building Test Suites for each specification.

The Working Group welcomes participation from representatives of W3C Member organizations. To enable a broad spectrum of input, the group also anticipates the active participation of individuals as W3C Invited Experts (read the policy for approval of Invited Experts). Participation from W3C Members and non-Members alike will help ensure the goals of this charter are effectively addressed. Invited Experts in this group are not granted access to Member-only information.

Participants are reminded of the Good Standing requirements of the W3C Process.


This group primarily conducts its work on the public mailing list <public-mbui@w3.org>.

Information about the group (deliverables, participants, face-to-face meetings, teleconferences, etc.) is available from the Model-Based UI Working Group home page.

Decision Policy

As explained in the Process Document (section 3.3), this group will seek to make decisions when there is consensus. When the Chair puts a question and observes dissent, after due consideration of different opinions, the Chair should record a decision (possibly after a formal vote) and any objections, and move on.

Patent Policy

This Working Group operates under the W3C Patent Policy (5 February 2004 Version). To promote the widest adoption of Web standards, W3C seeks to issue Recommendations that can be implemented, according to this policy, on a Royalty-Free basis.

For more information about disclosure obligations for this group, please see the W3C Patent Policy Implementation.

About this Charter

This charter for the Model-Based UI Working Group has been created according to section 6.2 of the Process Document. In the event of a conflict between this document or the provisions of any charter and the W3C Process, the W3C Process shall take precedence.

Dave Raggett <dsr@w3.org>, W3C Staff Contact

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