The Classical Data Situation

The classical methods of statistical data analysis were designed for a relatively simple situation. First, the data were obtained for single individuals (persons, objects, products,…) which were the basic entities of the data gathering process by using interviews, experiments, archives, etc. Second, the recorded data concerned a list of one or several well defined variables and, third, these variables were single-valued insofar as the observation of each variable for a given individual resulted in just one single ‘value’ or ‘category’ such as in the statements: ‘the height of a person is 170 cm’, ‘the colour of a car is red’ etc. Depending on the situation, these variables were classified into quantitative (continuous or discrete) and qualitative (ordinal or nominal) ones.