By means of area wide measurement campaigns, characteristic parameters describing the power quality of grids, can be evaluated. Due to economical reasons, a maximum of information with a minimum of measuring devices shall be achieved. Redundant results must be avoided as well as loss of information. The minimum number of measuring devices and their locations depend on the grid topology, the electrical line parameters and the location of possible network disturbers. With the use of correlation- and regression analysis, nodes with similar characteristics regarding power quality can be identified. Base data for these analysis can be extracted from previous measurements or simulation studies. not assigned KP: Elektrizitätsversorgungsunternehmen