EN
The paper presents the methodology of experimental research described on the basis of KBN grants realized in 1992-1996. Biometrical topics from theese grants are contained in the following four fundamental problems: 1. Planning and analysis of one- and two-factor experiments carried out in incomplete designs. 2. Methods for the analysis of individual genetic and breeding experiments. 3. Methods for the analysis of series of variety trials and plant genetic or breeding experiments. 4. Methodology of experimental research applied to the results of DUS trials, plant protection and in legume breeding.