A method of examining relationships between variables, Based on the assumption that the observed and directly measurable indicators are only indirect and/or special externalities with more general characteristics. They are hidden variables because they are concepts or structures that are not available for direct measurement. However, It can be determined by analyzing the correlations between observable traits and highlighting factors that can be interpreted (provided that the structure is good) as a statistical expression of the latent variable. Factor analysis provided reliable results for psychological, intelligence and personality tests.