SD - SGML

We have the evolution of:

• Markup language, to
• Metalanguange / generalized markup, to
• SGML (metalanguage) and
• Application of SGML using
• Document Type Definitions (DTDs).

SGML - Standards

• SGML = ISO 8879, Standard Generalized Markup Language
• Related Standards
  • ISO 8613, ODA, Office Document Architecture: formating, imaging, interchange; represented in SGML or binary --- includes layout
  • ISO 10179, DSSSL, Document Style Semantics & Specifications

SGML - Explanation

• Is a
  • tagging language, DB language
  • extensible doc. descrip. language
  • metalanguage to define doc. types
• Supports
  • logical structure, hierarchies
  • file linking & addressing
  • multimedia and hypertext

Documents, DTDs, Procedures

SGML-encoded documents can be:

• checked for syntactic compliance with a DTD
• printed in accordance with DSSL specifications
• displayed on a screen
• indexed for context-specific searching
• translated into another representation

SGML - Markup

SGML allows 4 types of markup

• Descriptive: tags
• Referential: entity references
• Metamarkup: markup declarations
• Processing instructions: LINK, CONCUR

The most important type is Descriptive Markup.

• Elements
• GI (generic identifier) - found in start and end tags
• id= idref; attribute/value pairs
• content
• Top element = doc.
• Elements have content model (i.e., a grammar production)

Example

DTDs

• Define a class of documents.
• Specialize SGML for documents in a class.
• Use an attribute grammar.
• Use a bracketted grammar.
• Hierarchy support means nested content.
• Ordering means OHCO is fully supported.
• Developing a DTD: DTDspin, modular approach, DTD for theses, ACM's eclectic approach (but making sure formatters exist).

Our Uses of SGML

• CODER: dictionaries, INCARD (project with cardiology data)
• Project Envision
• Bibliographic records
• Transactions articles
• Tech reports (WATERS): for biblographic records instead of refer or BibTeX
• Dissertations and theses
• TREC, TULIP
• HTML and HTML+

Advantages of SGML

• Maintainability
  • Allows multiple use: Paper - screen; thesis - article - book
  • Immune to new WP s/w or new versions
• Portability
  • Author to online use to publisher
  • Electronic Manuscript Project (of AAP)
    • Guidelines for articles, books
    • Elements for mathematics, tables
  • Text Encoding Initiative (TEI)
    • Proposed and run by: Humanists, Linguists, Literary Community
    • Guidelines for: dictionaries, drama, poetry, sculpture descriptions, simultaneous translations, ...
• Benefits
  • Sharing, collaborating
  • Avoid rekeying, proofing, fixing galleys: initially, and on new editions
  • Derive bibliographies & citations
  • Immediately publish too in online databases and on CD-ROM
• Less Cognitive Demand, Better Support of Content Orientation
  • Element recognition only -> derive markup selection & performance
  • Focus on structure
• Special Assistance / Processing
  • Multiple views (recall LectorMotif)
  • Outlining / structure editing (e.g., Author/Editor)

Doc. Modeling w. SGML

• Characterize structure using DTD
• Depth / thoroughness of tagging
• Bibliographic entries, names
• Math, tables
• PAT model, representation, retrieval
• PAT and LECTOR specification files
• OHCO, grammar models --- especially if one avoids SGML customization
  • Minimization, entity references
  • CONCUR, processing markup
  • Extensive use of attributes
• Attach semantics / weighting / evidence effects -- to context

HTML References

• A Beginners Guide to HTML
• HTML Quick Reference
• Hyper Text Markup Language (HTML)
• A Beginners Guide to URLs

TEI Guidelines for Electronic Text Encoding and Interchange (P3)