Systematic generation of XML instances to test complex software applications

We introduce the XPT approach for the automated systematic generation of XML instances which conform to a given XML Schema, and its implementation into the proof-of-concept tool TAXI. XPT can be used to automatize the black-box testing of any general application that expects in input the XML instances. We generate a comprehensive set of instances by sampling all the possible combinations of elements within the schema, applying and adapting the well known Category-Partition strategy for functional testing. Originally, XPT has been conceived for application to the e-Learning domain, within which we briefly discuss some examples.