Requirements for WCAG 2.0 Techniques

Draft Version 0.2
20 November 2002

Introduction

[preamble text]

Requirements

• Techniques must be structured in such a way that multiple views can be achieved, including in particular:
  • Checklists
  • Test files
  • Techniques by conformance level
  • Others?
  This implies that Techniques must be highly structured and largely machine manipulable. It is expected that they will exist in XML documents conforming to the DTD/Schema in Appendix A.
• Each Technique must be assigned a unique identifier to enable machine-readable conformance statements.
• Techniques must be usable by a variety of audiences, including in particular
• Content developers
• User agent developers
• Evaluation tool developers
• Authoring tool developers
• Assistive technology developers
• Others?
• Each set of Techniques must apply to a distinct technology (e.g., HTML, CSS, SVG, ECMAScript).
• There must be a separate Core Techniques document that will provide information that is too specific for WCAG but not related to a specific technology, such as:
• Mapping to Unicode
• Media equivalents for multimedia
• Clear and simple writing (4.1)
• Supplementing with non-text content (4.2)
• Summaries and definitions (4.3)
• Others?
• Where technologies work together (e.g., HTML and CSS), relevant joint techniques must be presented with the host technology (e.g., HTML). If techniques do not involve interactions between the two technologies, they must be presented with the techniques for their respective technology only.
• Techniques must state to which versions of the technology they apply, that is, describe a practice to avoid or that will have a positive accessibility impact. They may specify all versions, all versions prior to or later than a particular version, or enumerate particular versions.
• Techniques may describe practices that are not yet supported by user agents, authoring tools, etc. in order to provide guidance for tool developers. When possible Techniques should also describe practices that work in contemporary tools.
• Each technique must map to a specific WCAG Success Criterion or Additional Ideas by URI and number for clarity and to enable auto generation of hybrid Guidelines/Techniques documents.
• There may be multiple techniques for each Success Criterion or Additional Ideas, clearly stated that they are alternate techniques.
• Each technique must state whether it fully implements the Success Criterion or Additional Ideas and if not provide references to other techniques (in the same or other Techniques documents) needed to complete the implementation.
• Techniques should be testable whenever possible and must declare whether they are considered testable. Guidance about testing methods may be provided.
• Techniques must [should?] include or link to test cases showing positive and negative implementations of the technique. [This implies the creation of a test suite that exists at a layer below the Techniques layer.]
• Techniques should include descriptions, commentary, implementation notes, links to resources or training materials, etc. to contain information not part of the structured data.
• Techniques documents must be versioned in such a way that updates to the documents do not break interdependencies that may exist among multiple documents (e.g., on Core techniques, HTML dependent on CSS, etc.).

Appendix A: XML DTD/Schema for Techniques

[To be provided]