1. A method of diagnosing an arc welding process by monitoring an electric arc welder as the welder performs the arc welding process by creating actual welding parameters between an advancing wire and a workpiece to create a weld, said welding process controlled by command signals to a power supply of said welder, said method comprising: segmenting said wave shapes into a series of time segmented states; selecting a specific waves shape state; monitoring a plurality of weld parameters occurring in one or more of said states at an interrogation rate over a period of time repeatedly during said welding process; calculating a plurality of quality parameters for each of said one or more states based on said measurements of said weld parameters during said welding process; and analyzing at least one of said plurality of quality parameters and said plurality of weld parameters to diagnose said arc welding process by determining one or more possible causes of one or more localized or continuous defects of the weld; comparing a value of each of said quality parameters calculated for each period of time to a corresponding expected quality parameter value to determine if a difference between said calculated quality parameter value and said corresponding expected quality parameter value exceeds a predetermined threshold; and when said difference exceeds said threshold, weighting said calculated quality parameter value with a magnitude weight based on said difference, and weighting said calculated quality parameter value with a time contribution weight based on a time contribution of its state to the wave shape including said state.