A visual formalism for graphical user interfaces based on state transition diagrams

We present a "lightweight" visual formalism that can be used to examine the state space complexity of an interface. The method can form a basis for designing, testing and documenting the \´front-end\´ component of a typical GUI forms based interface. The standard is intended to be free standing and seeks to address issues specific to forms based GUI interfaces. The method is based on a state transition diagram (STD) notation that is used to model the GUI component. STDs can be used at an early stage in the design of an interface to quantify and control surface level complexity. Further to allowing a visualisation of the complexity of an interface, techniques used in graph theory are applied to determine a novel measure of complexity that can then be used to better usability.