An educational psychologist is a psychologist whose differentiating functions may include diagnostic and psycho-educational assessment, psychological counseling in educational communities (students, teachers, parents, and academic authorities), community-type psycho-educational intervention, and mediation, coordination, and referral to other professionals, at all levels of the educational system. Many countries use this term to signify those who provide services to students, their teachers, and families, while other countries use this term to signify academic expertise in teaching Educational Psychology. Specific facts Psychology is a well-developed discipline that allows different specializations, which include; clinical and health psychology, work and organizational psychology, educational psychology, etc. What differentiates an educational psychologist from other psychologists or specialists is constituted by an academic triangle whose vertexes are represented by three categories: teachers, students, and curricula (see diagram). The use of plural in these three cases assumes two meanings; the traditional or official one and other more general derived from our information and knowledge society. The plural also indicates that nowadays, we can no longer consider the average student or teacher, or a closed curriculum, but the enormous variety found in our students, teachers, and curricula. The triangle vertexes are connected by two-directional arrows, allowing four-fold typologies instead of the traditional two-way relationships (e.g., teacher-student). In this way, we can find, in different educational contexts, groups of good teachers and students (excellent teaching/learning processes and products), groups of good teachers but bad students, and groups of bad teachers and good students, producing in both cases lower levels of academic achievements. In addition, we can find groups of bad teachers and bad students (school failure). This specific work of an educational psychologist takes place in different contexts: micro-, meso- and macro-systems. Microsystems refer to family contexts, where atmosphere, hidden curriculum, and expectations and behaviors of all family members determine, to a large extent, the educational development of each student. The term mesosystem refers to all variety of contexts found in educational institutions, knowing that different variables such as geographical location, institution marketing or type of teachers and students, etc., can influence the academic results of students. Macrosystem has a much more general and global nature, leading us, for example, to consider the influence that the different societies or countries have on educational final products. One illustrative example of this level can be the analyses carried out on data gathered by the PISA reports. This approach would be the essence of educational