Harmonization of land use class sets should consider both space and time, as the objective should include harmonization of land use change to analyse environmental processes and problems. Analysis of major class sets reveals that a parametric approach with two parameters may suffice: 'function' that describes land use in an economic context and 'activity' that is defined as the combination of actions resulting in a certain type of product. An example of land use harmonization in Albania illustrates how creation of a reference system based upon the principles of classification, using the synergy between classification and information technology concepts and based upon the 'function' and 'activity' parameters can facilitate harmonization between land use class sets in parallel to achieving land use change harmonization. As not only data quality is of paramount importance, further research is necessary to define quantitative measures to determine harmonization results both at class level and between class sets.
