In socialism, Working Psychology, has as its fundamental objective, the continual improvement of the working conditions and the living conditions of the workers and this is obtained by the conformation of work. To determine these changes, to transform the environment, scientifically speaking, it is necessary to reckon from the knowledge of the present requirements of the working post and its analysis. This explains why the study of an analysis of a working post has not a purpose of its own but depends of the practical or theoretical objective we have in mind. The way we determine the requirements of the working post will depend of our concept of working requirements and fundamentally of the object of the investigation to which it serves as base. This is why we should use the direct determination of the requirements of work only when we want a general information of the working activity, evaluating the significance and grades of importance of the requirements. When we give up the differentiated analysis of the working activity, we have to be conscious of certain mistakes we can commit in the immediate evaluation of the requirements, it is then very important to select the adecuate methods to obtain the necessarv information so we can diminish many of the errors in which we might fall. The present article deals with some of these aspects.