The catologues of visual and eclipsing binaries have been analyzed by means of a mulivariate statistical method, with the purpose of putting into evidence mutual relations among the observed quantities as well as clustering properties in the mulri-dimensional space. Preliminary results of the analysis show several interesting feataures, and a physical interpretation can be attempted. Nevertheless, observational selection effects play an important role. The way back to the understanding of formation and evolutionary properties is extremely difficult, and unbiased conclusions about fundamental parameters as the initial period and mass ratio distributions cannot be obtained.