ZedAI Introduction
From zedwiki
ZedAI is a colloquial short form for ANSI/NISO Z39.86 Authoring and Interchange Framework.
It is one of the two major parts of the ANSI/NISO Z39.86 2009-2010 revision.
This document summarizes its rationale, nature, and intended role in XML-based authoring, within the DAISY community and beyond.
Why focus on Authoring in DAISY?
Previous DAISY specifications have focused on describing accessible information products that end users receive: distribution formats. The DAISY Digital Talking Book (DTB) has been the classic distribution format pioneered and promoted by the DAISY Consortium.
The DAISY 3 (Z39.86-2002 and 2005) standard defines an XML grammar (originally called DTBook, more recently also DAISY XML, and in some parts of the world also known as "NIMAS files") that is intended to contain the textual component of a DAISY DTB multimedia presentation. The DTBook grammar was also designed as a "Conversion DTD"; meaning that its purpose is to capture and represent paper print books in XML format. In other words, DTBook was designed to be a format for creating content, or an authoring format.
As the DAISY community has grown exponentially over the last decade, so has the uses of and expectations on the DAISY format. The print book scope has become too tight. Further, many organizations have started implementing a production system where DTBook/DAISY XML serves as an XML Master Document that is used to produce several output formats - not only DAISY DTBs, but also e-text, large print, and occasionally even Braille.
As a result of this, it has become increasingly clear that combining the roles of authoring and distribution formats into one and the same XML grammar does not work well. The functional requirements of an XML authoring format and an XML distribution format are not always in harmony. Therefore, the Z39.86 Committee has decided to treat these two different functions separately in the forthcoming revision of the DAISY standard. There will be one specification focused entirely on an authoring format and another specification focused entirely on distribution formats. This approach will allow us to strengthen the effectiveness and expressive power of the DAISY format both in terms of authoring and distribution, since we will no longer have to make technical compromises when trying to cram functionally disparate requirements into the same standard.
What is the Z39.86 Authoring and Interchange Framework?
The Z39.86 Authoring and Interchange Framework (ZedAI for short) is a specification that defines an XML-based framework with which content producers can represent various types of information in an extensible, standards-compliant way, suitable for the transformation into multiple output formats.
Some key points about this definition:
- Handling various types of information
While DAISY's scope initially was about print books, today it is used for a wide variety of content such as newspapers, magazines, consumer medical information, audio tour guides, conference proceedings, corporate documentation, emergency preparedness, museum exhibits, and much more. The ZedAI framework addresses this by not imposing a limitation on the kinds of information resources that can be represented. The specification will describe not a single all-encompassing XML language, but rather a clear framework for the creation of languages, each of which can be custom-tailored for particular content types.
- Extensibility
Today, information is dynamic both in content and in delivery format. The ZedAI Framework is designed from the start to be nimble, to be able to adapt quickly to new kinds of uses. As noted above, it is designed as a means for creating custom languages for different purposes. In ZedAI, these are referred to as profiles. In order to encourage the growth and efficient creation of profiles, the framework will be built on smaller, specialized modules that can be reused and combined in different ways. And for cases where subtle differences between structures needs to be expressed within a single profile, there will be mechanisms in place for content producers to add these semantic inflections within the framework.
- Standards Compliance
The ZedAI Framework will be part of the planned major revision of the Z39.86 standard under the auspices of NISO. The framework in its turn builds on established standards from the W3C and ISO. By using a standardized format, organizations ensure that their content is interoperable and a safe investment in the long term, and that tool support will be provided from many vendors across the globe. By using existing standards where available, we are saving work by building on the recognized efforts of others.
- Supporting multiple output formats
ZedAI is an authoring format. It does not impose any limitations on what kinds of distribution formats can be created from it. We know that DAISY DTBs, E-text, Braille and large print are output formats that are within scope of the current DAISY community. We also know that by building the ZedAI framework to be extensible and adaptable at multiple levels, support for new output formats can be added and implemented as the need arises.
Who is the intended audience?
As inherited from the previous versions of ANSI/NISO Z39.86, the primary intended audience of the Z39.86 Authoring and Interchange Framework is producers and providers of accessible content (such as DAISY DTBs, Braille, e-text, and large print). The principles and building blocks of the framework are however generic enough to be adopted by any publisher that engages in XML-based parallel publishing.
Note: end-users (actual consumers of content) are not in the intended audience. The Z39.86 Authoring and Interchange Framework should be seen as a provider-side format, used as a source from which final end-user products are subsequently rendered.
What about the Interchange part of the name?
Today, an increasing number of organizations are interchanging accessible materials such as DAISY DTBs and (to a lesser extent) Braille. The interchange is currently based on transferring readymade end user products between organizations and countries.
We call the framework the Z39.86 Authoring and Interchange Framework to underline the fact that this format can also yield tremendous effectiveness in the interchange/interlending domain. For example, by transferring documents in the more abstract form that the Authoring and Interchange Framework represents, organizations can postpone the decision on what output format these documents should be rendered to. Organizations can ultimately let the end user decide, at lending time.
What is the basic design approach used in the Z39.86 Authoring and Interchange Framework?
Its quite simple, actually, at least if you're a bit geeky.
The XML grammars referred to above in this document are technically referred to as Profiles.
The XML document model of a ZedAI Profile is compound. This means that a profile's document model consists of a set of abstract XML grammar modules, that are combined to form a concrete document model.
By employing compoundness and modularization as the primary mechanisms of document model composition within the ZedAI Framework, we ensure that the framework is natively extensible, and as such adaptable to various information domains and processing contexts.
This architecture also encourages reuse of grammar modules; either such created explicitly for use in the Z39.86 Authoring and Interchange Framework; or such created by other standards bodies, in other contexts.
To ensure that we stay technically compatible with the mainstream, and to avoid reinventing wheels, the architecture builds upon the principles defined by W3C XHTML Modularization 2.0.
Note: Technical readers may want to have a look at a more lengthy overview of the framework components.
How will Profiles and Modules be provided to the public?
The ANSI/NISO Z39.86 Maintenance Committee intends to host an online catalog where certified profiles (and their modules) are provided. New profiles and modules will be appended to the certified catalog over time.
Where can I learn more?
Please refer to the Authoring_&_Interchange_Working_Group main page for more information.
A document describing the architecture of the ZedAI framework is also available.
The Working Group tracks issues and develops schemas etc at the Google Code ZedNext Repository
