home
EMR
XML
specs
opnote
download
links
contact
The Open Healthcare Group
Left A Smarter Way for Better Healthcare Right
XML and Healthcare
What is XML?
Over the years, Hypertext Markup Language (HTML) has made the web one of the most revolutionary means of structuring and presenting information. The limitations of HTML, however, have forced authors to concentrate more on the presentation of web pages rather than the structuring of information. HTML is largely superficial. It describes how a Web browser should arrange text, images and buttons on a page and is thus primarily concerned with the appearance of the page. Therefore, although you may be able to pull up a list of medications on an HTML webpage, your computer would not know what to make of the information. It would simply be interpretated as a list of text.
XML, or eXtensible Markup Language, is the next evolutionary step in markup languages. XML tags describe what the information actually is rather than merely what it looks like. For example, in HTML, an order for a shirt would be labeled as boldface, paragraph, column and row. XML, however, would label it as price, size, color and quantity. A program would then be able to recognize the information as such and thus be able to manipulate the data much more easily.
In addition, as a meta-markup language, XML gives an author the power to create their own set of tags as they are needed. Although not required by the XML standard, Document Type Defitinition (DTD) allows authors to codify the vocabulary and syntax that they wish to use. XML can, therefore, be used to describe information from any domain or industry. Various disciplines, such as chemistry, astronomy and mathematics, have already begun to develop their own domain-specific markup languages. Biosequence ML (BSML) was designed to allow geneticists to exchange and manipulate the flood of information produced by gene-mapping projects such as the Human Genome Project. BSML allows researchers to search through vast databases of genetic code and display the data as meaningful maps and charts rather than as obtuse strings of letters.
Since XML describes the meaning of content independent of its display, XML enables exchange of information between different computer systems. Once data is described in XML, designers can then apply rules organized into stylesheets to reformat the work automatically for various devices, such as mobile phones and handhelds. Furthermore, the information can be readily displayed in all of the world's major languages. A Chinese browser, for instance, will have no problem reading an XML page.
As a non-proprietary format, XML is also not encumbered by licenses, copyrights, patents or other intellectual property right restrictions. Everyone can freely use the XML format. Furthermore, XML is easy to read and write, by both machines and humans.
Some of the goals for XML, as stated in the annotated specification by Tim Bray, are as follows:
  • XML shall be straightforwardly usable over the Internet
  • XML shall support a wide variety of applications
  • It shall be easy to write programs which process XML documents
  • XML documents should be human-legible and reasonably clear
  • XML documents shall be easy to create. [Next]

1. What is XML?

2. Why XML in Healthcare?