A set of measurement techniques that can find multiple DC operating points, as well as explore regions of operation that are unobservable with traditional experimental methods, is described. These techniques are particularly useful for transistor circuits that exhibit hysteresis, S- and N-type current-versus-voltage curves and multiple dc operating points (typically with different physical stability properties). These techniques are the experimental version of well known homotopy techniques used in the simulation of dc operating points and can be applied without access to a numerical simulation model. Such numerical simulation techniques used to identify and describe such behaviors are also surveyed and compared to the measurement techniques described herein.