in a method for determining the size and shape value for a solid material , in particular scrap metal , in an arc furnace , an electrode flow fed to an electrode for forming an arc furnace between the electrode and the solid is measured and from the measured electrode flow ), an effective measurement value of the electrode flow is determined and from the measured electrode flow ) , a flow part associated with a frequency range of the measured electrode flow is determined , and a quotient of the flow part and an effective measurement value is formed as a measurement of the shape and size value of the flow . thus , a method is provided that enables a property of a fusible element introduced into one of the arc furnaces to be determined .