The unknown acquaintance, or the impact factor and others

Nobody doubts the importance of the scientific performance's evaluation. At the same time its way divides the group of experts. The present study mostly deals with the models of citation-analysis based evaluation. The aim of the authors is to present the background of the best known tool - Impact factor - since, according to the authors' experience, to the many people use without knowing it well. In addition to the "non-official impact factor" and Euro-factor, the most promising index-number, h-index is presented. Finally new initiation - Index Copernicus Master List - is delineated, which is suitable to rank journals. Studying different indexes the authors make a proposal and complete the method of long standing for the evaluation of scientific performance.