ABSTRACT
Epidemiological studies and statistical analysis of data require the existence of a system for collection and maintenance of masses of different pieces of information. The interval scale is identical to the ordinal scale except that the increments designated by the number are equal. A ratio scale is an interval scale in which a zero can be established or a value such as a threshold of detection for chemical analytical equipment can be agreed on. Data management is that segment of scientific activity dealing with data record keeping, data quality control, and accountability of all the data collected in the process of carrying out a research project. The technological aspects of data acquisition methods have developed into a rapidly evolving technology. Computers, mainframe and personal, have already changed the organization of procedures for data management and the skills of professional and technical personnel attached to this fundamental aspect of research.
