Аннотация
In this paper we present the basics of planning, carrying out and statistical analysis of experimental studies. We describe the most common types of experimental studies, interpretation of results as well as the main advantages and disadvantages of these studies. Practical examples of experimental studies with step-by-step algorithms of sample size calculation and statistical data analysis using formulas and free software are presented. Moreover, we present a few international and local examples of experimental studies in the fields of clinical medicine and public health.