IMPEDANCE SPECTROSCOPY (IS) IS ONE OF THE MOST INFORMATIVE TOOLS FOR CHARACTERIZATION OF ELECTROCHEMICAL SYSTEMS. IT IS BASED ON THE RESPONSE OF SYSTEM TO A PERIODIC ELECTRICAL STIMULUS, IN A WIDE FREQUENCY RANGE. HENCE, THE RESULTANT DATA INCORPORATE, THOUGH NOT DIRECTLY OBSERVABLE, INDIVIDUAL CONTRIBUTIONS OF COUPLED UNDERLYING SYSTEM’S PROCESSES, EACH RESPONDING TO A LIMITED FREQUENCY RANGE. HOWEVER, AS IMPLICITLY NOTED, IS DOES NOT DIRECTLY MEASURE THE INFORMATION OF SYSTEM’S PROCESSES, AND SO, THE INFORMATION HAS TO BE EXTRACTED FROM THE DATA. TO DOING SO, THE COMMON APPROACH IS TO CONSTRUCT A HYPOTHETICAL WORKING MODEL (KNOWN ASTHEORETICAL APPROACH) THAT BEST DESCRIBES THE IS DATA. THIS HYPOTHETICAL MODEL INDEED DESCRIBES THE SYSTEM’SSTRUCTURE.AFTER VALIDATION OF SUCH MODEL USING SOME CRITERIA, THE OBTAINED MODEL’SPARAMETERS ARE ASCRIBED TO THOSE OF THE SYSTEM. HOWEVER, AS THE WORKING MODEL IS CHOSENA PRIORI (I.E. SYSTEM’S STRUCTURE IS HYPOTHESIZED AND NOT IDENTIFIED), ONLY THE SO-CALLED PARAMETRIC IDENTIFICATION IS POSSIBLE. AN ALTERNATIVE TO THETHEORETICAL APPROACH FOR EXTRACTION OF INFORMATION FROM IS DATA IS THE SOCALLED EXPERIMENTALAPPROACH, WHICH IN ADDITION TO PARAMETRIC IDENTIFICATION, ENABLES DERIVATION OF THE WORKING MODEL (I.E. STRUCTURAL IDENTIFICATION) FROM EXPERIMENTAL DATA (JUST CONTRARY TO THE THEORETICALAPPROACH WHICH ONLY IDENTIFIES SYSTEM’S PARAMETERS). DIFFERENTIAL IMPEDANCE ANALYSIS (DIA), AS ANEXPERIMENTAL APPROACH, CAN BE REGARDED AS A NEW TOOL FOR ANALYSIS OF IS DATA. DIA IS BASED ON TRANSFORMING IS DATA BY SCANNING THE SO-CALLEDLOCAL OPERATING MODEL (LOM) OVER ENTIRE DATA. THIS RESULTS IN NEW SET OF DATA WHICH CAN BE APPLIED, THROUGH FURTHER ANALYSIS, FOR PARAMETRIC AND STRUCTURAL ANALYSES.