The W3C Device Independence Working Group (DIWG) has released three specifications supporting its goal of ensuring that presentation devices can access Web content appropriate for their capabilities. The Device Independence Principles document articulates the Working Group's vision of a device independent Web, describing "device independence principles that can lead towards the achievement of greater device independence for web content and applications." The revised draft on Authoring Challenges for Device Independence "discusses the challenges that authors commonly face when building web content and applications that can be accessed by users via a wide variety of different devices with different capabilities. This document examines the effects on authors and the implications for authoring techniques that assist in the preparation of sites that can support a wide variety of devices and proposes a derived a set of requirements for such techniques." A first public working draft of Glossary of Terms for Device Independence provides a glossary of terms used in other documents produced by the Device Independence Working Group.

The W3C DIWG has been chartered to "study issues related to authoring, adaptation, and presentation of Web content and applications that can be delivered effectively through different access mechanisms." Specifically, the WG is tasked with: (1) collecting requirements for Web access via various kinds of presentation device; (2) reviewing related specifications within and outside of W3C; (3) providing use cases and requirements to related activities within W3C; (4) describing techniques which allow authors to better manage device dependencies; (5) [as needed,] proposing recommendations that will lead to enhanced device independence."

Bibliographic Information

• Device Independence Principles. Edited by Roger Gimson (HP). Co-edited by Shlomit Ritz Finkelstein (invited expert), Stéphane Maes (IBM), and Lalitha Suryanarayana (SBC Technology Resources). W3C Working Group Note. 01-September-2003. Version URL: http://www.w3.org/TR/2003/NOTE-di-princ-20030901/. Latest version URL: http://www.w3.org/TR/di-princ/. Previous version URL: http://www.w3.org/TR/2001/WD-di-princ-20010918/. A diff-marked version is also available.

• Authoring Challenges for Device Independence. By Rhys Lewis (Volantis Systems). W3C Working Group Note. 01-September-2003. Version URL: http://www.w3.org/TR/2003/NOTE-acdi-20030901/. Latest version URL: http://www.w3.org/TR/acdi/. Previous version URL: http://www.w3.org/TR/2002/WD-acdi-20021018/.

• Glossary of Terms for Device Independence. By Rhys Lewis (Volantis Systems). W3C Working Draft 25-August-2003. First public Working Draft. Version URL: http://www.w3.org/TR/2003/WD-di-gloss-20030825/. Latest version URL: http://www.w3.org/TR/di-gloss/.

• Published earlier: "Delivery Context Overview for Device Independence." Edited by Roger Gimson (HP). W3C Working Draft. 13-December-2002. "Delivery context refers to the set of attributes that characterize the delivery environment. Among these attributes, the ones that are most relevant for achieving device independence are those that characterize the presentation capabilities of the access mechanism, the delivery capabilities of the network and the presentation preferences of the user. Delivery context information is typically used to provide an appropriate format, styling or other aspect of some web content that will make it suitable for the capabilities of a presentation device. The selection or adaptation required to achieve this may be performed by an origin server, by an intermediary in the delivery path, or by a user agent. From the point of view of device independence, the main concern is accurately reflecting the capabilities of the access mechanism and the presentation preferences of the user. Given appropriate information about the delivery context, the presentation of the delivered content can be selected or adapted to be functional on that device, or may be further customized to provide a better user experience..."

• Published earlier: "Core Presentation Characteristics: Requirements and Use Cases." Edited by Markus Lauff and Amy Yu (SAP). W3C Working Draft. 10-May-2003. Produced by the W3C Device Independence Working Group. "The purpose of defining these Core Presentation Characteristics is to provide a common set of property or attribute definitions that can be reused in many contexts in which the presentation capabilities of a presentation device need to be considered. The use of well-defined Core Presentation Characteristics will simplify the task of adapting content to a specific presentation delivery context. The document sets out what is meant by 'core' and 'presentation,' what should be included in the definition of each characteristic, what should be defined when grouped characteristics into collections, and what kind of characteristics should be included in the core..."

From the Device Independence Principles

Excerpts from the 2003-09-01 W3C Note on Device Independence Principles:

"In recent years, there has been a proliferation of types of device and access mechanisms using the Web, extending far beyond the conventional personal computer. These access mechanisms range from web tablets, appliances and TVs in the home, to mobile devices including phones and PDAs, and access mechanisms for the physically challenged. Connectivity capabilities have also evolved to include high bandwidth modems, LANs and wireless networks. Simultaneously, the needs and expectations of the user with regards to access, availability and consumption of web content have also evolved. Users now expect to get to critical information through different access mechanisms from different locations and at different times during their day. For example, a user may want to access some web information using a PC connected to a cable network when at home, but when out of the house the same user expects to access the same information using a PDA connected through a mobile phone network..."

"Content authors can no longer afford to develop content that is targeted for use via a single access mechanism. The key challenge facing them is to enable their content or applications to be delivered through a variety of access mechanisms with a minimum of effort. Implementing a web site or an application with device independence in mind could potentially save costs, and assist the authors in providing users with an improved user experience anytime, anywhere and via any access mechanism."

"The goal of this [Device Independence Principles] document is to suggest that web content and applications can be authored, generated or adapted for a better user experience when delivered via many different web-connectable access mechanisms. The general phrase 'device independence' is used for this, although the access mechanisms may include a diversity of devices, user agents, channels, modalities, formats etc."

"The vision we share with others is to allow the Web to be accessible by anyone, anywhere, anytime, anyhow. The focus of the W3C Web Accessibility Initiative is on making the Web accessible to anyone, including those with disabilities. The focus of the W3C Internationalization Activity is on making the Web accessible anywhere, including support for many writing systems and languages. The focus of the W3C Device Independence Activity is on making the Web accessible anytime and anyhow, in particular by supporting many access mechanisms (including mobile and personal devices, that can provide access anytime) and many modes of use (including visual and auditory ones, that can provide access anyhow)."

"These three Activities are complementary, and our interests overlap. For example, being able to select an auditory mode of use on a device may be essential to someone with a visual disability. The focus of device independence is on matching web content to the needs, capabilities and limitations of the delivery environment. We wish to minimize the extent to which web content is authored in a way that is only deliverable on a restricted set of devices."

"The principles described here are intended to be complementary to the wider Architecture of the World Wide Web, which consists of a wider set of requirements, constraints, principles, and choices that influence the design of the Web and the behavior of agents within it. Implementations of these principles should also conform to the Web Content Accessibility Guidelines, the User Agent Accessibility Guidelines and the Authoring Tool Accessibility Guidelines...

The principles are independent of any specific markup language, authoring style or adaptation process. They do not propose specific requirements, guidelines or technologies. It is intended, however, that these principles be used as a foundation when proposing greater device independence through, for example: (1) guidelines for authoring of content and applications that use existing markup languages; (2) modifications and extensions to existing markup languages; (3) designs of adaptation tools and processes; (4) evolution of new markup languages. .."

About the W3C Device Independence Activity and Working Group

"The World Wide Web is the universe of network-accessible information. The Web is becoming accessible from a wide range of devices including cellular phones, TV, digital cameras, and in-car computers. A threat we face is that only parts of the Web will be accessible from these devices. W3C is dedicated to ensuring that the Web universe is not fragmented. In keeping with W3C's goal of universal access, and the fundamental design principles that govern W3C technological development, interoperable languages and protocols and single-authored content should prevail."

"W3C is aware of standardization efforts relating to mobile Web and TV Web integration within other standardization bodies. The Consortium and its Members are well-positioned to lead development to avoid incompatibility and achieve single Web authoring. The W3C Device Independence Activity is working to ensure seamless Web access with all kinds of devices, and worldwide standards for the benefit of Web users and content providers alike."

"The Device Independence Working Group tracks devices and services in development or already deployed, collects requirements on Web access with those devices, studies the domain-specific issues to find commonality among them, and reviews related specifications within and outside W3C."

The aim of the W3C Device Independence Working Group is to "avoid fragmentation of the Web space accessible with various kind of devices. The Working Group set out its goals and motivation during the first year work under the previous charter. The Device Independence Working Group collects the requirements on Web access with various devices, reviews related specifications within and outside W3C, and describes techniques which allow authors to better manage device dependencies and propose recommendations in the areas of delivery context and device independent authoring. Please see the Device Independence Working Group page and the Device Independence Working Group charter for further information on the constitution of the Working Group." [adapted from the Activity Statement and home page description]

A summary of W3C work on specifications for Device Independence is provided in the table of Section 3: Revised Milestones for the updated Working Group Charter.