Abstract: An approximation graph for behaviors of the man/machine interface of an application that is obtained automatically by this method can be defined as follows: the nodes (N1, N2, N3) of the graph represent sets of screen objects encoding screens for display during execution of the application and characterized by a property in common. A screen object can be represented by one node only; the oriented arcs (?) of the graph connecting an origin node (N1) to a destination node (N3) illustrate the possibility of transiting, as the result of an event occurring, from a screen described by an object of an origin to a screen described by an object of a destination.