This book presents the results of the research carried out to obtain a Master's degree in Educational Sciences at the Autonomous University of Asunción - UAA-PY. Its aim is to analyse the use of the results of the National Assessment of School Performance (ANRESC) as an instrument of intervention for school managers, in order to ensure the learning of primary school students in the early years. The results presented through the research show that it is up to the manager to develop collective work and democratic management, where power is shared with the professionals involved in the process, so that everyone participates in drawing up the school's pedagogical proposal with the participation of the school and local communities, represented by the School Councils, in order to meet the real needs of the educational process.