This training manual covers the planning, organization and conduct of scientific research in the field of medicine, biology and psychology, the description of the data obtained, the identification of statistical links and differences between medical and biological data. There are questions, test tasks and situational tasks for self-control of knowledge . The textbook is illustrated with figures, diagrams and tables. The publication is intended for graduate students studying in the areas of training 06. 06. 01 Biological Sciences, 30. 06. 01 Basic Medicine, 31. 06. 01 Clinical Medicine, 32. 06. 01 Medical prophylactic case and 37. 06. 01 Psychological Sciences .