It is shown that the energetically evaluated load-indentation measurement procedure introduced by Rother and Dietrich is equivalent to the analysis of the force-indentation depth-curve by means of the well known Bernhardt formula. A disadvantage of the proposed "differential load feed" (DLF) procedure is that differentation enlarges the scatter of the experimental curves. Deviations of the indenter tip from its ideal shape and surface roughness also influence the experimental results in the case of DLF analysis in a manner as one observes for these methods usually used to analyse force-indentation depth-curves.