Disclosed herein are signal identification methods and systems. In some examples, the method and/or system allows appliances to be associated with their electrical usage. In one example, a method for determining whether a load is in a steady state or in transition includes analyzing a time series of electric power or current measurements on at least one circuit, at least one load coupled to the at least one circuit; and determining whether the load is in a steady state or a transition. Also disclosed is an appliance identification method. Further disclosed is a method of mapping unlabeled appliances which utilizes a STEC Table which summarizes linkages between transitions and steady state clusters.
ACKNOWLEDGEMENT OF GOVERNMENT SUPPORT
 This invention was made with government support under Grant No. 0912914 awarded by the National Science Foundation, Grant Nos. DE-FG36-08G088161 and DE-FG30-08CC00057 awarded by the United States Department of Energy. The government has certain rights in the invention.