ANSI/NISO Z39.86-2002: NFF File Format Proposals: National File Format: NCAC: CAST

At the first NFF Committee meeting, held January 7, 2003 in Washington D.C., the user requirements were discussed. We recognize that not all requirements were identified at this meeting, but the overall direction and thinking was very clear. In the process of gathering requirements for the ANSI/NISO Z39.86 standard, we went through a very similar process. We heard the same requirements being put forward that were identified at the NFF meeting. In fact we tracked new requirements that were brought up at the NFF meeting. We did hear some new and interesting requirements, but only a few. The first draft of the features and functions for the NFF that have been released to the committee confirms that observation. As members of the NFF Committee, and as members of the Advisory Committee for ANSI/NISO Z39.86-2002 to formally propose that the XML-based DTBook element set incorporated in this standard be endorsed by the NFF Committee as the recognized US National File Format.

ANSI/NISO Z39.86-2002 comprises a comprehensive solution for making information accessible to print-disabled persons. It includes as a core item the DTBook element set for markup of a textual content file. It is this textual content file that can be used by publishers to provide their content in a form to be used by authorized entities. Z39.86 also incorporates the components necessary to create a synchronized presentation in multiple media. It provides great flexibility for both the producer and the user.

This proposal does not address all issues brought before the NFF Committee. It does not address the issues of a national repository, who should supply figure and other graphical descriptions, what is the target population to be served, who is responsible for providing the XML files, or final format distribution issues. This is putting forward a proposal for the source file format for the textual content.

ANSI/NISO Z39.86-2002 is Already a Recognized Standard

The American National Standards Institute (ANSI) and the National Information Standards Organization (NISO) have already endorsed this standard. Both of these are formal standards bodies recognized in the United States. In addition, the Digital Accessible Information System (DAISY) Consortium, has endorsed this specification for all new developments and is planning to move this standard towards the International Standards Organization (ISO).

Maintenance of ANSI/NISO Z39.86-2002

The National Library Service for the Blind and Physically Handicapped (NLS), a division of the Library of Congress, is the formal maintenance agency for ANSI/NISO Z39.86-2002. Who better than the Library of Congress to support the national standard? The Advisory Committee, consisting of members from a variety of agencies serving the print disabled, is in place to identify any errata, review additions and modifications, incorporate new specifications, and to promote the standard. In other words, this is a living standard that has committed individuals working in the disability community ready to support the standard.

Invitation to the NFF Committee to have Experts Participate in the Maintenance and Development of the Standard

The Advisory Committee for the ANSI/NISO Z39.86-2002 is ready to have an appropriate number of qualified individuals from the NFF Committee serve as experts in the ongoing maintenance and development of the standard. We want to extend this as an offer to the NFF Committee. These individuals can contribute to the maintenance of the standard and to help incorporate new requirements into the standard. It is not a requirement that the NFF Committee provide individuals, but we want to extend this invitation.

The Advisory Committee meets face-to-face at least twice a year, holds at least monthly conference calls, and participates on an active email discussion list to address the issues associated with the standard. The funding for this participation is provided by the organizations employing the committee members.

Why Use DTBook as the National File Format for Accessible Textbooks?

ANSI/NISO Z39.86-2002 was developed to make print material accessible to print-disabled persons. It includes as a core item the DTBook element set for markup of a textual content file. DTBook was developed especially for use in rendering print materials accessible to persons with print disabilities. The three most likely alternative element sets were evaluated and rejected for the following reasons: HTML was not found to be detailed enough to support our needs. Docbook played was deemed too rigid. Since the print textbooks that are the starting point are so varied in structure, it is not possible to use a DTD which enforces a prescribed document structure, as Docbook does. TEI was found to be too complex. TEI was developed for scholarly use, and as such was expected to be used by highly trained and motivated persons. Even TEI Lite covers many areas that are of no interest to our community and has far more elements than does DTBook.

We concluded after much debate that we needed a conversion Document Type Definition (DTD); that is, an element set that describes the structure and content of a print book in sufficient detail to enable it to be converted to alternative formats. (See an online paper, Digital Talking Book Production Process, from CSUN 99. Link opens in new browser window). Once work on the DTD began, we concluded that it would make sense to begin with common HTML tags, as they were already widely used and their semantics are understood, and to augment them as needed. The final tag set contains many HTML tags as well as a good number of new tags developed for this application.

In describing DTBook, the "pizza" metaphor has been used to clarify the use of the base tag set and additional modules. One can think of the DTBook tag set as being a basic cheese pizza, and modules as toppings that can be added as desired. The DTBook tag set contains the common elements found in textbooks and reading materials used in the K-12 arena. The over arching structures, such as front matter; headings for parts, chapters, sections, and sub-sections; rear matter, etc. are defined. Block-type elements, such as paragraphs, block quotes, lists, footnotes, sidebars, etc. are also defined. Inline items, such as emphasized text, acronyms, citations, footnote references, sentences, etc. are identified. A complete list of these can be found in the standard. The point here is that the basic types of books can normally be represented in XML using this basic cheese pizza.

Now think of separate modules that can be added, as toppings on a pizza. A poetry module that would contain the tags needed to mark up poems is under development by the Z39.86 community. The community has also done preliminary work on a module for the markup of plays. These might be considered green peppers and onions for the pizza. The modules that can be added to the basic structure depend on the information one needs to convey.

The World Wide Web Consortium (W3C), the standards setting body for the Internet, has used this modular approach as well. One topping we may consider adopting for our pizza is the work they have done with MathML: http://www.w3.org/Math/

This is a module we should consider using when providing information in the field of mathematics. This is definitely meat on the pizza! The work conducted in the W3C paid close attention to the needs of persons with disabilities, but there is a lot of work, requiring significant resources, that needs to be done with accessibility tools to take advantage of math provided in XML in this way. The math work has been discussed by the Z39.86 Advisory Committee, and we have demonstrated that a MathML segment can be incorporated in a DTBook document.

Other modules will be required as time goes on, such as for other scientific disciplines, dictionaries, music, and so forth. The DTBook DTD was designed to meet the majority of the markup needs in non-technical books. It was deliberately kept lean so it would be easy to learn and use. The other modules to be developed would only be used as needed, thus minimizing complexity for users. DTBook incorporates a simple XML mechanism, described in section 4.2.2 of the standard and in the DTD itself, for incorporating tags from other element sets as needed

Supporting Materials for the NFF

Much more than the identification of an XML tag set must be in place to support a National File Format. Guidelines must be identified that clarify the tags, their semantics, and their proper use. The presence of semantics, or the meaning of a tag, is critical for a reading system to correctly present information to persons with disabilities. With print, it is the visual information that helps the reader to use the information efficiently. The eye can take in a whole page at a glance and the student learns to visually identify headings, sidebars, footnotes, etc. However the student with a disability accesses the equivalent information by a reading system that understands the meaning of the tags and presents different types of information differently depending on the student's needs.

For example, it is important for a reader to know if they are reading a paragraph, a list item, or a block of quoted text. This semantic information is provided in the source files by applying the correct tag. The publishers asked us to associate the description of XML tags with something familiar in the publishing industry. The Chicago Manual of Style was chosen, as it is a definitive reference work used in the publishing industry to identify visual elements and their usage in print.

A set of "Structure Guidelines" has already been developed to support the application of the DTBook DTD. This was recently revised following the passage of Z39.86 in March of 2002.

In the Structure Guidelines you will find each element semantically defined, with reference to the Chicago Manual of Style, or another authoritative reference work. Examples of usage are provided with each tag.

Momentum Behind the ANSI/NISO Z39.86

One key factor behind the ever-growing enthusiasm for Z39.86 is the support for the XML source content identified in DTBook. Demonstrations at the NIST 2001 Electronic Publishing conference showed a source file encoded in DTBook, and from that file braille, a Microsoft Reader version, and a Digital Talking Book were generated. Many formats from a single source. The support for Z39.86 ranges across a variety of areas:

Finally, for those of us involved with standards and the disability community over the past ten years, we have never before seen as much support for a technical specification. In fact, part of the inspiration to endorse a National File Format comes from the huge success that the ANSI/NISO Z39.86-2002 standard has already enjoyed.

Glossary

Docbook - DocBook provides a system for writing structured documents using SGML or XML. It is particularly well-suited to books and papers about computer hardware and software, though it is by no means limited to them. In short, DocBook is an easy-to-understand and widely used DTD. Dozens of organizations use DocBook for millions of pages of documentation, in various print and online formats, worldwide. (Norm Walsh)

DTBook - An XML element set (dtbook.dtd) that defines the markup for the textual content of a DTB (Digital Talking Book).

TEI - Text Encoding Initiative. Initially launched in 1987, the TEI is an international and interdisciplinary standard that helps libraries, museums, publishers, and individual scholars represent all kinds of literary and linguistic texts for online research and teaching, using an encoding scheme that is maximally expressive and minimally obsolescent.

XML - The Extensible Markup Language (XML) is a standardized language for marking up files containing structured information.

XML as a source Format

XML allows a content developer to separate structural and semantic information from presentational information. For example, when creating a textbook chapter in XML, the developer could identify and encode ("tag") items for both structre (heading, section, page number, sidebar) and semantic (summary, elaboration, definition) meaning.

Presentation features (font type, font size, font color, etc.) would not be encoded in the source document in order to allow a variety of output formats, each of which can have elements such as font size and color customized to the accessibility needs of individual students.

With XML, content developers can use a wide range of �tags� to mark up content so that its format can later be customized. They are not limited to a set of proprietary tags and can even define their own tags and create domain-specific vocabularies.

A number of organizations (DAISY Consortium, Open eBook Forum, Web Accessibility Initiative, publishers, etc.) have developed specific tagging schemas for marking accessibility, educational, and structural features in each textbook prior to its transformation. Using XML, these tagging schemas can be combined or cross-referenced in a manner that can be processed and transformed into different outputs.

The tagging structure of the files can insure that they are consistent, correct, and maintain the structure of the text book, e.g., Part, Unit, Chapter, etc., so that all students can follow a teacher�s directions regardless of the version--digital or print--that they are using.

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