With the help of statistical usage models individual test cases or complete test suites are automatically provided by simple push button operations.

Statistical Test Case Generation

Usage models are graphical models and represent

  • usage states for modelling the user behavior during the interaction with the system, as well as
  • state transitions to specify the reaction of the system on a user's interaction.

For example, the input of a search item in the search field of an Internet browser is an interaction between the user and the browser and displaying a list of web pages that fulfill the search criterion is the expected response of the system. Both usage states input and output of a list with web pages as well as the state transition between these usage states that is triggered when the interacting user is pressing the Enter key are described in the usage model.

Usually there are many alternatives to move from a given usage state to possible successor states. For example, instead of pressing the Enter key in our example a different action may be performed, such as switching to another window by using the mouse. This will bring the user to another usage state.

The probability that a particular action can be performed is called transition probability between the usage states.