1. A method of creating a composite eye diagram for a collection of measured data signals from a System Under Test, the method comprising the steps of: (a) assigning data signals of interest to be members of a collection; (b) sampling at times relative to a reference signal the voltage of each data signal assigned to the collection; (c) for each data signal of step (b), populating respectively associated component data structures with TIME, VOLTAGE, and NUMBER OF HITS information useable to to create a component eye diagram for each such data signal of step (b); (d) traversing the component data structures of step (c) and combining their data content according to a selected rule into a result data structure, the combined data in the result data structure representing a composite eye diagram; and (e) displaying the composite eye diagram represented by the result data structure of step (d).