In the last two decades of the 20th century, the term access has begun to have a specialized and somewhat technically oriented meaning in the library community. Specifically, access is used as an alternative to acquisition of library materials. In other words, the library has fulfilled its mission if it gets the requested information for a patron even though a particular library might not have it. Access also refers to the ability of a computer to find and retrieve a citation or document in an electronic database. In both cases, access is enhanced by the associated technology. In the first case, interlibrary networking facilitates finding remote sources of information. In the second, a data collection is organized through software and made available through a combination of computer hardware and software.
But what of the human side of access? Is there yet another possible meaning or use of the term as it applies to making buildings and materials accessible to patrons with special needs? Certainly many libraries have led the way in making their facilities accessible to the handicapped. What if the disability is visual impairment? Once patrons are inside the building, what do libraries offer if their needs require alternative forms of typical library materials? Unless the library is specifically oriented toward visually impaired patrons, chances are good that access to the material is virtually impossible.
This problem provides an opportunity to apply technology to facilitate access for the print-disabled. Yuri Rubinsky and his International Committee for Accessible Document Design (ICADD) colleagues have devised a method of electronic document markup and transformation based on the Standard Generalized Markup Language (SGML) which leverages the existing document structure and enables rapid production of alternative forms of a text for the visually impaired. This article discusses Rubinsky's explanation of the process delivered as part of the Distinguished Seminar Series at OCLC on October 11, 1994. We will briefly cover the background of Rubinsky's work, discuss SGML and the automated transformation process, and suggest what this process might imply for patrons, libraries, and librarians.
A basic SGML text consists of a Document Type Definition (DTD) and the document content; content is composed of markup and data. The DTD defines the valid markup elements for a document type and what they mean. In other words, a DTD is a descriptive envelope for the content of the document. For example:
<:!DOCTYPE ARTICLE [ <:!ELEMENT ARTICLE -- (AUTHOR, TEXT) <:!ELEMENT AUTHOR -- (#PCDATA) <:!ELEMENT TEXT -- (#PCDATA) <:!ATTLIST TEXT style CDATA #implied ]The preceding DTD defines a document type article as consisting of two structural parts, author and text. The elements author and text are further defined by the terminal symbol PCDATA which means that the contents of this element is parsed character data, i.e., data characters in the text that are not markup. Finally, the text element has an attribute style.
In the "document instance," markup tags surround pieces of document content and describe the function of the pieces in the document's overall structure. Attributes modify the elements by carrying additional information about the document section. In the following example, the tags are in bold and the attribute is in italic:
<article> <author>Yuri Rubinsky</author> <text style=emphasized>This is a SHORT article</text> </article>The resultant printed output given the above DTD and document instance could be:
This is a SHORT article
Note that we said that the resultant output could appear like the string above. This is because an (output) application could use the style attribute value "emphasized" to italicize the text. No physical manifestation is presumed by the style attribute value.
A key aspect about a DTD is that it allows you to validate attributes and attribute values for each element without marking up the document again for a special output application (like Braille). The SGML parser determines whether the document structure is valid. The output application (print, Braille, Mosaic, etc.) determines what the special markup attributes mean.
Rubinsky cites the production of his novel, Christopher Columbus Answers All Charges, as an example of the successful use of the ICADD Architecture and the SDA transforms (Rubinsky and Giacomelli, 1993). The SDA transforms were used throughout the creation of the work. As soon as the authors completed their intellectual activity, the work could be submitted to publishers to create versions for various visually impaired readers. Following the receipt of the electronic version of the SGML text, it took two hours to create the Braille version; 90 minutes to make a voice-synthesized version; two days to create the large print version. Rubinsky is quick to point out that the fact that the work was a novel expedited the transformation process, but he believes that similar gains can be achieved for texts in all subject areas. Clearly, complex texts will take longer to transform, but will require significantly less time than the eight months it now takes. As a footnote to this publication process, the trade paperback version of Christopher Columbus . . . appeared three months after the print-disabled versions, thus making it the first book to achieve this distinction.
I am grateful to my colleague, Dr. Keith Shafer, for the supplemental material and examples of SGML.
Dr. Keith Shafer offers the following definition: "SGML is a meta-language for writing DTDs. A DTD describes how a document conforming to it should be marked up. For instance, a DTD will describe which structural tags (elements) may occur in the document and in what order . . . Simply put, a DTD describes a class of documents. Documents can be validated against a given DTD to see if they conform to the desired format."
Rubinsky, Yuri, and Marc, Giacomelli. 1993. Christopher Columbus Answers All Charges. Erin, Ontario: Porcupine's Quill.
Presented October 11, 1994. Yuri Rubinsky is president and co-founder of SoftQuad, Inc.