Biometry has to improve the quality of decision making both in biomedical research and in clinical practice

The leading principles of biometrical design, evaluation and decision making in biomedicine can be summarized as follows: (1) formulation of the problem to be solved and of the specific question(s) to be answered; (2) definition of the population in study, ways of sampling and manoeuvres (treatments); (3) determining the kind and number of variables (time intervals of measurement, investigated biomedical parameters); (4) performing the pilot study if necessary (to arrange randomized blocks, to form hypotheses); (5) formulation of zero (alternative) hypothesis, setting the values of alpha(beta) risk; (6) ordering the sample sizes; (7) testing the type of statistical distribution and the homoscedasticity of the obtained data; (8) calculation of the point and interval (confidence, tolerance) estimates; (9) performing the chosen tests, e.g. on the significance of differences or correlations; and (10) the conclusions for science and practice, with eventual return to point (1) on a higher level of knowledge.