In this report the authors present information on the bibliometric instruments and their importance in measuring the quality of scientific journals and researchers. They in particular the history and deployment of the impact factor of the existing Institute for Scientific Information since 1955. Are presented and discussed the criticism regarding the inadequacy of the impact factor for evaluation of scientific production, misuse and strategies editorial handling of the bibliometric index. It is presented to the new classification CAPES for the journals, based on various criteria and the impact factor and its influence on national scientific and academic life. The authors conclude that, despite all obstacles and discussions, the impact factor of the Institute for Scientific Information is still an useful tool and the only isolation available to assess the scientific and intellectual productivity.