The course aims to familiarize students with the principles and logic of scientific method, by introducing some basic concepts and tools in empirical research. Course objective is to provide a statistical vision of reality: starting with the observed variability of a phenomena, it develops a reflection on the variability and errors inherent to the process of observation and measurement, in order to understand how all the empirical knowledge is actually of sampling nature. It takes place as well as mindset and statistical tools are needed to address the study of any phenomenon. The first part of the course is structured around the concept of statistical distribution, and describes the methods for the analysis and synthesis of the information collected. In the second part of the course deals with the analysis of dependence between two variables, and discusses the concept of causality. Finally, the principles of statistical inference are presented: sample estimation and statistical testing of hypotheses, with the aim of making understood primarily their logic and meaning.