A method and apparatus for controlling a physical system responsive to an input
to produce a selected output comprises defining a virtual identity system that
includes the physical system for receiving the input to provide an actual output.
A quality of identity of the virtual identity system is checked using at least
a function of the actual output. In a preferred embodiment, adjustments are made
to a model of the physical system as a function the quality of identity in order
to render the correct input more efficiently and accurately.