SGML, XML and the Kona Architecture

What is SGML? -- An Acronym zStandard - International standard ISO-8879 zGeneralized - Not tied to a single machine, platform or system zMarkup - Describes information about the content of a document zLanguage - Definitions of the structure of the document contains can be written

Sample SGML Document <!DOCTYPE REPORT PUBLIC "-//KonaExample//DTD Prescription //EN" [ ]> Amoxicillin 250 mg. capsule 30 1 cap(s) 3 times daily until gone 0 may substitute AB

What SGML Provides z a list of elements which appear in a document za specification of the order and frequency in which these elements appear in the document (DTD) za verification that the marked up document conforms to the specification (parsers or validations)

Elements zElements are delimited with start tags and end tags Start tagContentEnd tag Tylenol One element

Attribute Syntax Attributes immediately are specified after the element they are associated with Start tagAttributeContentEnd tag Tylenol One element with one attribute

What’s a DTD ? zDocument Type Definition zDescribes the structure of the document yThe names of allowable elements ythe content of each element type ythe structure of the document including xthe order in which elements must appear xhow often elements can appear ythe properties of the elements (attributes)

What is the Difference between HTML and SGML? zHyperText Markup Language (HTML) zAn application of SGML zA DTD for authoring documents to be distributed via the World Wide Web zFormats documents for viewing on a computer screen

Why not use HTML? zDoes not offer a rich tag set zNo mechanism to structure documents in a clinical manner zInstable as a standard zDelivery format not a collection technology zLoose document type

What is XML? zeXtensible Markup Language (XML) zXML = SGML with a few exceptions: yA DTD is not required yProvides stylesheets for presentation in a web browser (XSL) ySome SGML syntax is not supported yDesigned for simple processing of diverse types of documents and data

The Role of XML zWhen HTML does not meet the needs zWhen collection of information is required zWhen information resources are of long term value zWhen there are complex relationships between information resources (links)

XML Example <PRESCRIPTION> Prescribed medication: Amoxil Form: capsule Dosage: 25 mg daily </PRESCRIPTION>

What is the KONA Proposal? zProposal zArchitecture that allows for varying levels of complexity in clinical documents zInterface that is a mediator between two applications or systems zExchange mechanism from a document centered perspective with varying levels of requirements

The Kona Architecture zMulti-layered schema consisting of three layers zA basic, abstract layer to exchange narrative documents (ProseDoc) zA layer that provides simple classification (ClinicalContent) zA layer that requires greater clincical semantics

The KONA Architecture

Moving Boxes zContent: shoes zMy Label: Master Bedroom Closet: slippers, running shoes, hiking boots zForeman Mover’s Label: First Upstairs Right Room zActual Mover’s Label: Upstairs

A Transformation Prescribed medication: Amoxil APPLICATION KONA Architectural Forms specify how tags are changed: Prescribed medication: Amoxil Transform to

SGML Architectures SGML architectures facilitate exchange between SGML documents & differing DTDS yOrganizations will most likely create their own DTDs to best meet their needs ySemantics vary by granularity, localization, and specialization

Kona Design Assumptions zKona builds on HL7; 2.3 used for proposal zDocuments contain narrative text and data (codes) zNot all clinical documents require the same degree of codes or markup

Flexible exchange: an oxymoron? zCentral dilemma of all information exchange standards: zlocal diversity, responsive to change zglobal rigidity, resistive to change zHow to provide extensible, flexible framework for information, yet retain the ability to exchange it freely?

Flexible exchange: Kona methodology zProvide central information model : RIM + Meta DTDs zProvide context for narrative text zDevelopment not required for mapping from local/specialized model to exchange model