ATLAS.ti and XML
"XML is the ASCII of the Future" - Tim Bray
XML, the eXtensible Markup Language, is a universal standard for information exchange between applications and today is used as such in nearly all information technology-related domains. ATLAS.ti has supported XML since the 4.2 release, and we continue to strengthen the central role of XML.
ATLAS.ti features XMLcentrally. Codes, memos, and entire HUs can be exported to XML format. Exporting codes and memos as XML files allows you to transfer all or only selected codes or memos between HUs. But exporting entire HUs to XML opens up endless possibilities for creating powerful reports, conversions to other applications, and even enables the vision of a completely integrated data management that transcends proprietary standards.
XML – What is it?
In case you are not familiar with XML, like HTML, it can be briefly described as a type of document markup language. XML, however, has the advantage that it is less dependent on the capabilities of a particular application (Web browsers for HTML). 
imnportantly, though, XML concentrates on actually structuring information. Structured information contains both content (actual words, pictures, etc.) plus some indication of what role that content plays (for example, text content inside a "heading" has a different meaning from content in a "footnote"; content in a "figure caption" differs from content in a "database table", etc.). Almost all documents contain some structure, and a markup language is a mechanism to identify this structure in a document. The XML specification defines a standard way to add markup to documents.
Using XML, programs can exchange data via a standard data interface.
If you create an XML output file, it can be read by other applications that support XML. One main advantage is that the application can select and define the elements and the layout of the display independently from any display information contained in the document. This is commonly achieved with the aid of so-called stylesheets.
What does it look like?
XML is short for eXtensible Markup Language. This is already quite a useful description when you compare it to its "competitor" or predecessor HTML, short for HyperText Markup Language.
The crucial term is "extensible", NOT "extended". HTML was intended to enable the exchange of documents and complex information across different technologies, operating systems, browsers, etc. It was also designed as a language which describes the logical structure of documents.
If you look at today’s HTML code (right-click and select "View Source" when browsing a web page), you will have a hard time identifying content amidst the chaotic "noise" produced by tags representing tables, frames, buttons, rulers, fonts, images, indentation, etc.
Both HTML and XML are descendants of a much more powerful (and more abstract) language called SGML, Standard Generalized Markup Language. Like SGML, XML allows new languages to be defined and created, a capability that HTML does not offer. While HTML is a ready-made language itself, XML is a meta-language for defining new languages.
HTML provides no clear separation of content and presentation. With a fixed set of tags, there is no way to clearly mark-up document content in a meaningful manner.
If you have ever seen the source code of an HTML-coded web page, you can easily recognize two of the main distinguishing characteristics of XML:
- The presence of tags (e.g., <MEMO>, <SPEECH TURN>) which are not available in the fixed set of HTML tags (where new tags are proprietary or at least deviations from the standards). The tags used in an XML file represent YOUR data without invalidating any standards! A raw XML file is shown below.
- The absence of presentation-related information (tables, fonts, images, rulers, etc)
An XML version of an interview section with some added information could look this:
If you are interested in learning more about XML, you may want to look at the following online article:
Muhr, Thomas (2000, December). Increasing the Reusability of Qualitative Data with XML [64 paragraphs]. Forum Qualitative Sozialforschung / Forum: Qualitative Social Research [Online Journal], 1(3). Available at: http://www.qualitative-research.net/fqs-texte/3-00/3-00muhr-e.htm.
XML Stylesheets
ATLAS.ti's comprehensive XML output is the key to an entire universe of data management and data interchangeability.
XML is a universal and generic meta-standard that defines general data structures. The real beauty (and power!) of XML is not so much that it can be directly imported by other applications, but that it can be very easily manipulated in many different ways and hence serve a great many purposes at once:
- transform entire projects into pretty much any program format
- shape data and present work results any way you desire by using standard Web design techniques
- extract and recombine data segments according to sophisticated program logic that goes beyond of what even ATLAS.ti can do
ATLAS.ti XML stylesheets use pure XSLT, a universal Web standard that is widely accepted and that can be learned without great effort. Many resources are available all over the Web to help you get up and running with XSLT quickly.
If you have created (or extended) a stylesheet yourself, why not share it with other ATLAS.ti users? We now host a special forum just for XML and XSLT applications of ATLAS.ti. Visit the community at http://forum.atlasti.com
ATLAS.ti already comes with a selection of stylesheets for you to put to immediate use. But they also serve as examples for your own styleesheet authoring efforts. If you are unfamiliar with this powerful tool, go to the Tools menu and select XML | XML Converter.
